The engine model and serial numbers appears on a metal tag or decal that's attached or affixed to the flywheel shroud, on the carburetor side of the engine. If there's no tag or decal that originally came with the engine, or if the engine block was replaced with a replacement short block or if the blower shroud has been replaced, there's no way of knowing exactly what year the engine is. All you'll know is the year of the blower shroud itself. Tags/decals and flywheel shrouds can be swapped from one engine to another and there are no numbers or identification characteristics on the blocks themselves (except for the 10hp through 14hp engines has 9 head bolts, the 16hp has 10 head bolts and the 18hp is OHV). Therefore, to see what size the engine actually is, it's best remove the cylinder head and measure the bore and stroke to determine engine size. Because a 10hp can be bored and stroked to a 12hp, using a 12hp piston, rod and crank, and a 12hp can be bored to a 14hp, using a 14hp piston, rod and crank.
Bore, stroke and valve sizes of 4hp through 18hp single cylinder Kohler engines:
| Engine | K90 (3.6hp) K91 (4hp) |
K141 (6¼hp) |
K160 (6.6hp) |
K161 (7hp) |
K181 (8hp) |
K241 (10hp) |
K301 (12hp) |
K321 (14hp) |
K341 (16hp) |
K361 (18hp OHV) |
| Bore (std.) | 2.375" | 2.875" | 2.875" | 2.938" | 2.938" | 3.250" | 3.375" | 3.500" | 3.750" | 3.750" |
| Stroke | 2.000" | 2.500" | 2.500" | 2.500" | 2.750" | 2.875" | 3.250" | 3.250" | 3.250" | 3.250" |
| Valve Sizes | 1.262" int. 1.262" exh. |
1-3/8" int. 1-1/8" exh. |
1-3/8" int. 1-1/8" exh. |
1-3/8" int. 1-1/8" exh. |
1-3/8" int. 1-1/8" exh. |
1-3/8" int. 1-1/8" exh. |
1-3/8" int. 1-1/8" exh. |
1-3/8" int. 1-1/8" exh. (early) 1-3/8" exh. (late) |
1-3/8" int. 1-3/8" exh. |
1-7/16" int. 1-13/32" exh. |
MODEL NO. (Deciphering model number to determine basic description of engine.)
Example: Model K321PT
K = K-series engine | 32 = Cylinder displacement (approximate cubic inch) | 1 = Single cylinder | PT = Pump model/Retractable start (Version code below Ê)Another example: Model K301AQS
K = K-series engine | 30 = Cylinder displacement (approximate cubic inch) | 1 = Single cylinder | A = Narrow Base Block and/or Special Oil Pan | Q = Quiet Model (Quiet Line) | S = Electric Start (Version codes below Ê)Version Codes:
A = Narrow Base Block and/or Special Oil Pan
B = Basic Engine
C = Clutch ModelG = Generator Application
P = Pump Model
Q = Quiet Model (Quiet Line)R = Reduction Gear
S = Electric Start
T = Retractable StartST = Electric Start and Retractable Start
EP = Electric (Power) Plant
SERIAL NO. (Year engine was manufactured.)
| [E] - 1 7 2 452 Letter code |
[9 0] 7 6 4 3 0 First two digits (if seven digit number). |
[1 0 0] 2 6 6 9 2 First three digits (if eight digit number). |
[1 5] 0 1 8 9 7 5 9 1 First two digits (if ten digit number). |
| A............1965 B............1966 C............1967 D............1968 E...(early)1969 |
10-19...(late)1969 20-29...........1970 30-39...........1971 40-49...........1972 50-59...........1973 60-69...........1974 70-72...........1975 73-79...........1976 80-89...........1977 90-94...........1978 95-99...........1979 |
100-109....1980 110-119....1981 120-129....1982 130-139....1983 140-149....1984 150-159....1985 |
15............(late)1985 16....................1986 17....................1987 18....................1988 19....................1989 20....................1990 21....................1991 22....................1992 23....................1993 24....................1994 25....................1995 |
| The remaining digits of serial number are factory code (line/shift at factory when engine was assembled on that day). These numbers are for warranty purposes only. | |||
SPECIFICATION NO. Engine Code à Model
Code à Model
26, 27, 31......K91 (4hp) |
Code à Model
29 .................K141 (6¼hp; [small bore]) |
Code à Model
46..................K241 (10hp) |
Code à Model
60..................K321 (14hp) |
| NOTE: The three numbers and the letter following the first two numbers (not shown above È) are the specific variation to the engine to meet OEM specifications. No information is available from Kohler to what these numbers represent. | |||
The Differences Between the Old Kohler K-series and the Newer Kohler Magnum Engines -
The Magnum engines replaced
the K-series in later years. The Magnum engines are basically the same engine
as the K-series. The main differences are, besides the sheet metal that covers
the block, the Magnum has solid state electronic ignition, a fixed main jet
(Walbro) carburetor and the starter fastens to the bearing plate instead
of the engine block. And there are no provisions for using ignition points.
Most of the external and all the internal parts are interchangeable, and
most aftermarket (high-performance) parts are interchangeable with either
engine.
A Magnum model M10, M12, M14 or M16 (10-16hp) engine can be used in a Cub Cadet. The block will need to be converted to a narrow base by cutting off the flanges on each side and cut threads in the holes in the block for a narrow oil pan. Also, because of the 3/8" flywheel retaining bolt, an aluminum clutch hub adapter with a 3/8" hole will need to be used, acquire a 5/8" to 3/8" reducer/step washer. (I make these.) Everything else should fit in the tractor with no problems.
BUYER BEWARE! A word of caution before purchasing a used pulling engine: Remove the cylinder head and oil pan (they're easy to remove), and then inspect the internal parts for damage and/or excessive wear. If the seller refuses to allow the head and pan to be removed, then it'll probably be best not to purchase the engine.
And if you're looking for some yellow paint to paint your Cub Cadet with, try your local farm and home supply store. They usually have International Harvester Yellow. It closely matches the color of Cub Cadet yellow.
Why Aluminum Block Engines (except V-Twins) Don't Work Well for Pulling Competition -
Most aluminum engine blocks will "bend and twist" a few thousands of an inch when hot and under pulling stress. Therefore, they'll lose valuable compression because the valves become unseated and the piston rings lose partial contact against the cylinder wall. Not to mention the main radial ball bearings are also put into a bind under the stress of pulling.
If the crankcase is building up too much air pressure in an OHV aluminum block engine, and blowing oil out the crankcase breather, the main cause of this the cylinder head(s) are warped and needs to be resurfaced on a large, flat sanding disc. New head gaskets needs to be installed, too. What happens is the metal in the heads between the pushrods (where there is no head bolt) become warped due to normal engine operating heat. New aluminum "bends and twists" a few thousands of an inch as the block and head(s) get hot for the first time. Crankcase oil plugs the gap as the piston travels downward on the intake stroke, and part of the compression goes into the crankcase upon the compression stroke. The engine will probably not blow oily smoke out the exhaust either. Once repaired, this shouldn't happen again.
Cast iron engine blocks on the other hand hold their shape a lot better when hot and under stress. Aluminum engines work best for conditions that doesn't place them in a lot of stress. Such as ATVs, racing go-karts, racing lawn mowers, etc. Because there's fresh air moving over the engine, keeping the metal cool, and the block isn't being strained by the vehicle pulling a heavy load. That's why cast iron Kohler engines work best for competition pulling. Because cast iron is able to "hold its shape," handle high operating temperatures, severe stress, high compression and very high rpm (above 4,000 rpm). This is why riding mowers, lawn tractors, lawn and garden tractors all have aluminum block engines. And most garden tractors have a cast iron engine block.
In addition, on the cast iron block single cylinder Briggs and Stratton and Tecumseh engines, the valve stems are parallel to the cylinder. This means that the valve heads set further away from the piston. And in the cast iron block single cylinder Kohler engines, the valve heads set closer to the piston (valve stems and lifters are angled 4°). Therefore, the other engines can't build up as much compression as Kohler engines can. Plus, they can't flow as much air in and out of the combustion chamber at high rpm, like Kohler engines can.
These are things that can be done to virtually any flathead twin cylinder engine to gain more power and torque:
- Check that the cylinder walls are in good condition and not severely scored or worn. If they're in good condition, deglaze them, and if the pistons are reusable, install new piston rings.
-
If it's a Kohler engine model KT17II, KT19II, M18 or M20, leave out the
cylinder-to-crankcase gaskets and apply
Clear RTV Silicone Adhesive Sealant instead. Doing this
should allow the pistons to come approximately .030" closer to the top of
the cylinders, increasing the compression ratio slightly. By the way -
I've always preferred to use
Clear RTV Silicone Adhesive Sealant for two reasons: being
it's an adhesive, it bonds parts together, forming a leak-proof seal; and
being it's clear, it makes for a clean-looking repair job. It can't be seen
between the parts.
NOTE: It's not recommended to use the series 1 engine models KT17, KT19 or KT21 because these engines don't have a pressure relief valve in the oil pump lubrication system, which could cause insufficient oiling to one of the connecting rod journals. - Perform a professional valve job. If it isn't already, regrind the intake valve faces and seats at a 30°/31° angles, respectively, and regrind the exhaust valve faces and seats a 45°/46° angles, respectively.
- Set the valve clearances at .006" for the intake valves and .010" for the exhaust valves.
- Resurface the cylinder heads on a flat sanding disc to insure proper head gasket sealing.
- In each cylinder head, relocate tip of spark plug closer to exhaust valve. To do this, weld up the spark plug hole, bore an angled hole toward the exhaust valve, then cut threads and mill seat area able for installation of the spark plug.
- Use full synthetic 10W40 motor oil. Full synthetic oil don't get hot like conventional (petroleum-based) oils do. It's more slippery and remains cooler even after the engine has been in operation for several hours to better protect internal parts for longer engine life. And I don't think it matters which brand of synthetic oil to use, because they all pretty much do the same thing.
FYI- Boring the cylinders to a maximum of .030" and installing .030" oversize pistons and rings won't help to increase the power that much. It'll only add about 1/10th of a horsepower with virtually no increase in torque. What increases the torque substantially is giving the engine a longer stroke. But these engines isn't capable of this.
Nothing else may be needed to be done to the engine, except for perhaps perform a professional tune-up. Or better yet, install electronic ignition. Also, many twin cylinder engines have inadequate valve clearances and this robs the engine of proper operation and valuable power. Set the valve clearances at .006" for the intake and .010" for the exhaust. After performing the tune-up and resetting the valve clearances, the engine should start quicker, idle better, accelerate with less hesitation and produce more power and torque at any rpm.
To perform a professional valve job on a twin cylinder flathead B&S or Kohler engine, the parts that will be needed are: two head gaskets, two crankcase breather gaskets, intake manifold mounting gaskets and valve stem seals (for intake valves only). New valve guides, especially for the exhaust valves, may also be needed. But that's to be determined once the valves are removed. A quality-made valve spring compressor tool is required to remove and reinstall the valves. The valve faces and valve seats angles are to be reground or recut at 45° (intake valve face for Kohler), 30° (intake valve face for B&S) and 46° (intake and exhaust seats for Kohler & exhaust seat only for B&S), 31° (intake seat for B&S), respectively. If you can't do this yourself, a local automotive machine shop can do it for you. You'll need to take the engine or tractor to the shop to have the valve seats reground or recut. Make sure they're reground or recut at the proper angle, too! And it'll be a good idea to have both cylinder heads resurfaced on a flat sanding disc to ensure proper head gasket sealing. The head bolts can be reused. They rarely go bad. Top of page
Why aluminum block engines (except v-twins) don't work well for pulling competition - Top of page
An aluminum engine block will "bend and twist" or flex a few thousands of an inch when hot and under pulling stress. Therefore, they'll lose valuable compression because the valves become unseated and the piston rings lose partial contact against the cylinder wall. Not to mention the main radial ball bearings are also put into a bind under the stress of pulling.
Cast iron engine blocks on the other hand hold their shape a lot better when hot and under stress. Aluminum engines work best for conditions that doesn't place them in a lot of stress. Such as ATVs, racing go-karts, racing lawn mowers, etc. Because there's fresh air moving over the engine, keeping the metal cool, and the block isn't being strained by the vehicle pulling a heavy load. This is why the cast iron block Kohler engines work best for competition pulling. I think that Kohler is the best engine for pulling. They're the "Chevrolet" of garden tractor pulling engines. Because cast iron is able to "hold its shape," handle high operating temperatures, severe stress, high compression and high rpm. This is why most riding mowers, lawn tractors and lawn & garden tractors have aluminum block engines. And most garden tractors have a cast iron engine block.
In addition, on the cast iron block single cylinder Briggs & Stratton and Tecumseh engines, the valve stems are parallel to the cylinder. This means that the valve heads set further away from the piston. And in the cast iron block single cylinder Kohler engines, the valve heads set closer to the piston (valve stems are angled). Therefore, Kohler are capable of producing more compression, and they can flow the air better in and out of the combustion chamber at high rpm.
How to Convert
a Kohler Command Pro V-Twin Vertical Shaft Engine into a Horizontal Shaft
-
- Drill the oil drain-back holes in the corners of the cylinder heads near the valve train so the oil can drain back down in the oil pan.
- The oil pump must be changed (pickup tubes are different).
- The vertical shaft engine has no horizontal mounting holes on the block. (They are on the sump cover.) So a couple of L-shaped engine mounting plates must be fabricated to convert the block into a horizontal shaft and mount the engine in the tractor frame.
- Various holes in the block must be blocked off (drain holes are different, etc).
- The intake manifold, throttle linkage and carburetor will also need to be swapped.
- Everything else on the engine should work with no modifications. The PTO end of the crankshaft will be a little long, being it's made for a vertical shaft engine. But it'll still work just fine in the horizontal position.
By the way - I don't build high-performance V-twin engines and I know very little how to improve the performance of them because no one here in Missouri pulls them. The only contacts I have concerning V-twin engine builders and high-performance parts are listed below Ê. Contact them and perhaps they can help you.
- Al Hodge Performance V-Twins. He modifies the Briggs & Stratton Vanguard V-twins for all types of racing and performance applications. Output ranges from 25 to 42hp. Modified engine weight is around 80 lbs. He supplies engines for some of the fastest Cushmans in the National Champion lawn mower racers, tractor pullers, Class Champion scale sprint cars, ATV's, hunting boat upgrades, etc. All of his engines are non-governed and include solenoid shift, high torque starters. Sorry, he doesn't have a manual or any printed literature....he offers cams, billet rods, high compression pistons, mega-valve machine ported heads, titanium valves, rev-kits, roller rockers, billet push rods, billet rocker covers, stroker kits, etc. Give Al a call @ 704-291-7825 Monday thru Friday 10:00 am until 4:00 pm EST. E-mail: pki@trellis.net
- R.P.M. - Rader Performance Motors When Performance Counts, Count on Rader Performance Motors! Services Include: Complete Engine Building - Stock, Stock-Altered and Kohler V-Twins Custom Flow Bench Water Brake Dyno Tuning = Maximum Horsepower Dyno Tested, Track Proven Performance Contact: Mark Rader | Phone: (740) 927-3312 | E-mail: rpmark@sprintmail.com.
- Frank Edwards of Galax, VA. Kawasaki water cooled V-Twin garden tractor high-performance. Selling performance parts and building complete pulling engines. Call for details. 276-236-5305. E-mail: sdrawde@ntelos.net
- Lakota Racing ( http://www.lakotaracing.com/ )
- Midwest Super Cub ( http://www.midwestsupercub.net/ )
- Performance V-Twins ( http://www.performancevtwins.com/ )
How to Convert a Briggs & Stratton Twin Cylinder Flathead Vertical Shaft Engine into a Horizontal Shaft -
The parts needed to convert
a vertical shaft twin cylinder flathead B&S engine into a horizontal
shaft model are as follows. The parts below
Ê must come off a horizontal shaft twin
cylinder flathead B&S engine.
- Acquire an oil pan off a horizontal shaft engine (to replace the side cover).
- Acquire an oil dipstick and tube off a horizontal shaft engine.
- Acquire a side cover off a horizontal shaft engine (to replace the oil sump cover).
- Acquire an intake manifold, carburetor and governor linkage controls off a horizontal shaft engine.
- Install a steel oil dipper on each connecting rod to lubricate internal parts.
- Drill oil drain-back holes in the block for the camshaft and crankshaft bearings so the oil will lubricate these vital moving parts and drain back down in the oil pan.
- Everything else on the engine should work with no modifications. The PTO end of the crankshaft will be a little long, being it's made for a vertical shaft engine. But it'll still work just fine in the horizontal position.
To install a twin cylinder engine into a Cub Cadet, on the narrow and wide frame Cubs, the frame rails will need to be cut down for installation of an opposed twin cylinder engine. But the spread frame Cubs are made for the opposed twin cylinder engine. And a V-twin engine will fit in virtually into any Cub Cadet with few modifications. The frame rails shouldn't have to be altered either. Go here for an example of a V-twin that was installed in a wide frame Cub Cadet: http://www.smallenginewarehouse.com/RepowerItems.asp?Brand=Cub%20Cadet&Model=1000.
When rebuilding an aluminum block
engine, remember - as an aluminum block and cylinder head get hot for the
first time, they "warp" or bend and twist a few thousands of an inch due
to normal engine heat. This is called block (and related parts) warping.
In other words, the metal "takes shape." It's normal for new engine parts
and unavoidable. So be sure to have the cylinder head and other parts resurfaced
on a flat sanding disc to insure 100% gasket sealing, and bore the cylinder
to insure a 100% piston ring seal. After the parts get hot again, they should
not bend and twist again. This is a one time deal.
How to Determine if an Engine Needs to be Rebuilt - (Most of this information applies to most small engines, automotive, farm and industrial equipment engines.)
First of all, oil usage is
controlled by the "snugness" of the piston in the cylinder or how cool the
engine operates. The below Ê are things
that can cause an engine to burn oil:
- Over-advanced ignition timing (past the 20° BTDC setting for gas).
- The [adjustable] high speed fuel mixture in the carburetor leaned out too much.
- A fixed high speed main jet Walbro carburetor used and the engine was operated above 3,200 rpm.
- Throttle shaft severely worn in the carburetor, creating a vacuum leak, leaning out the air/fuel mixture.
- Motor oil not changed regularly or too light of viscosity oil is used for warm weather.
- If the engine was ran with an excessively dirty air filter or without a quality air filter under dusty conditions.
Either or a combination of the above È will definitely cause an engine to overheat (except without an air filter), causing the rings to lose their tension against the cylinder wall, resulting in the oil being burned. I have seen all of these things happen to a good engine many times.
Kohler engines can be rebuilt multiple times, as long as everything in it is rebuildable. Before the engine is removed from the tractor and disassembled, first, remove the cylinder head and observe the top of the piston. If it's 100% coated with carbon, then the piston rings are in good condition. But if there's oil present and some of the carbon is washed away around the edges, this means that the rings and piston are worn and need replacing, or the cylinder needs to be rebored for installation of a new oversized piston and rings assembly. But if the cylinder is max'd out at .030" and worn, it can be sleeved back to STD size.
The cap on a connecting rod is precision machined (honed) to form an absolute perfect circle to match the rod it is installed on. If a cap is swapped from one rod to another and then installed in an engine, chances are, the rod will be too tight or too loose on the crank journal. If an oil dipper breaks off the cap, another cap can be used on the rod, but the cap (and rod) would need to be precision honed to form a perfect circle again.
And if the crank journal is worn, it can be reground undersize and a matching undersize connecting rod or one with bearing inserts installed. Or the crank journal can be reground until it's perfectly round again, and if the old connecting rod isn't severely scored or burnt, it can be resized to fit the odd-size reground journal. This would save money from having to purchase a high-dollar undersize connecting rod or it's useful for engines when a new replacement undersize rod is no longer available. The rod would still be strong and should last a long time, too. (As long as the engine isn't revved too fast or ran out of oil.)
To resize the rod so it'll fit to a few thousands of an inch smaller diameter crank journal, first, metal is removed from the mating end of the rod cap, then the cap is fasten to the rod. The big hole in the rod is now oblong or "egg shaped." Then the big hole in the rod is honed until it's .002" larger than the diameter of the crank journal. Honing reshapes the hole into a perfect circle again, only smaller in diameter. This works very well and it lasts as long as an ordinary STD size rod and crank journal. This can only be performed on a rod with a good bearing surface. It cannot be done on a burnt or heavily scored connecting rod because too much metal would need to be removed. Also, if the crank journal is worn beyond .030" undersize, it can be welded up and reground back to STD size. There's lots of tricks that can be used to rebuild an engine. The rebuilt engine should last a long time, too.
Now move to the valves. To test for leaking valves, with the cylinder head removed and the piston at TDC on the compression stroke (both valves fully closed), apply Liquid Wrench (spray) or WD-40 around each valve and then use [150± psi] compressed air to blow through the exhaust and intake ports. Wrap a rag around the air nozzle and place it snug against the port so full air pressure will be against the valve. If bubbles form around the valves when applying the air pressure, this means that the valves are leaking and a professional valve job is required.
To remove the engine from a typical IH Cub Cadet, first disconnect the battery negative terminal and disconnect all the wiring from the engine and fuel line if the gas tank is separate from the engine. Then remove the PTO clutch engaging linkage, remove the engine mounting bolts, then slide the engine forward so it'll clear the clutch disc or driveshaft, then lift the engine out of the tractor.
Now remove the oil pan and connecting rod cap. Observe the rod cap for scoring or burning. Replace or repair it if necessary. Also, the crankshaft journal may be worn and if it is, it will need to be reground to the next undersize. And have the crank journal mic'd (precision measured with a micrometer) to determine if it's excessively worn. If it is worn, it can be reground to .010" and a .010" undersize connecting rod can be used or the original rod can be bored for installation of .010" bearing inserts. But if it needs to be reground to .020" or .030", the rod will need to be bored for installation of matching bearing inserts. The only OEM rods available without a bearing are STD size and .010" undersize.
If the cylinder wall is badly scored or tapered, have it bored to the next oversize. The only pistons available for a stock engine are STD, .010", .020" and .030". If the cylinder is worn beyond for installation for a .030" piston/rings assembly, it will need to be sleeved for installation of a STD size piston/rings assembly. But if building an engine for more power, don't have the cylinder bored to a maximum of .030" if it doesn't need it. Because a .030" overbore won't necessarily give an engine more power. Having a longer crankshaft stroke increases the power.
And if you're wondering, the model K141 (6¼hp) engine has a bore diameter of 2-7/8". The model K161 (7hp), which replaced the K141, has a bore of 2-15/16". It use the same piston/rings assembly as the model K181 (8hp) engine. Pistons/rings assemblies are no longer available in the 2-7/8" size. When rebuilding a K141, the cylinder must be bored for use with a 2-15/16" piston/rings assembly, which will then make it a model K161. The connecting rod and crankshaft are the same in the K141 and K161, but is different in the K181.
The following specialty tools are required to disassemble and reassemble
a Kohler engine. Most of these tools are available at auto parts stores and
on eBay.
More sophisticated tools or tooling and machinery is required to perform machine work on certain engine components, such as: bore the cylinder; regrind the crankshaft journal(s); bore connecting rod for installation of bearing inserts; recut or reground the valves and seats; etc. In most cases, the valves can be reground. But if they're severely worn, they need to be replaced. I sell most of the parts required to perform a complete engine rebuild. Most common parts are: piston and rings, gaskets w/oil seals, valves, carburetor kit and tune up kit. |
Most of the time, cleaning the burnt aluminum from a crankshaft journal won't work because the journal itself may be scored or worn. Therefore, it'll be better to have it reground to the next undersize and install a matching undersize connecting rod. Or if an undersize rod or bearing inserts isn't available, have it reground undersize (to wherever it "cleans up") and resize the connecting rod for proper fit.
With engines when there's no an undersize connecting rod or bearing inserts available, if the crank journal is worn beyond STD size and need to be reground, being 99% of all worn journals are "egg-shaped" or oblong, it can be reground to where it is perfectly round again, and then the connecting rod can be resized so it'll fit the smaller diameter undersize journal.
To resize the rod so it'll fit to a few thousands of an inch smaller diameter crank journal, first, metal is removed from the mating end of the rod cap, then the cap is fasten to the rod. The big hole in the rod is now oblong or "egg shaped." Then the big hole in the rod is honed until it's .002" larger than the diameter of the crank journal. Honing reshapes the hole into a perfect circle again, only smaller in diameter. This works very well and it lasts as long as an ordinary STD size rod and crank journal. This can only be performed on a rod with a good bearing surface. It cannot be done on a burnt or heavily scored connecting rod because too much metal would need to be removed. Click here if you're interested in having this service performed.
Don't Be A Slob When Rebuilding An Engine!
Always be professional whenever
you rebuild an engine! Before assembling a fresh engine, always take
the time to provide a neat and absolutely clean work environment. Make sure
that your repair table or bench is sturdy enough to support the weight of
a fully assembled cast iron bock Kohler engine. And make sure that your tools,
shop/business towels, engine parts and hands are clean, too. Don't allow
any dust or dirt to enter the work area, including the engine block and it's
internal parts. If necessary, place the engine parts on a large, clean cloth
or cardboard to help keep them clean and organized until they're ready to
be installed. The reason everything should be kept as clean as possible is
because even the smallest bit of dirt inside an engine will "grind away"
at the internal parts when the engine is in operation, causing unnecessary
and expensive wear.
You can also use an automotive engine stand to rebuild a Kohler engine. Just use the two starter bolt holes on the side of the block to mount your engine to the stand. You can completely disassemble and reassemble the entire engine, except for the starter, and you can get at everything on the outside and inside of the engine with no problems.
To "basically" overhaul or rebuild
an engine that burns a lot of oil, all that needs to be done on a Kohler
engine is remove the oil pan and cylinder head, disconnect the connecting
rod from the crankshaft and then drive the piston and rod out of the block
with a long wooden stick and a medium size hammer. Inspect the entire piston
and cylinder wall for wear. If no wear is evident, then install a new set
of rings on the piston (thoroughly clean the parts first though) and reinstall
the piston in the block as described. But to do a professional and complete
rebuild, read the rest of the information in this web page and linked pages.
It's common knowledge that most
metals retracts (shrinks) a few thousandths of an inch when cool or cold,
and expends (swells) a few thousandths of an inch when warm or hot. Knowing
this, when building or rebuilding an engine, keep in mind that if the engine
parts are either cool or warm, the end-play clearances for the camshaft,
crankshaft, valves, piston-to-cylinder wall, etc., will vary according to
the temperature conditions the engine is being assembled under. According
to the manufacturer's clearance specifications, allow for slightly greater
clearances if the temperature is cool (when working in a shop that don't
hold heat well during wintertime), and for lesser clearances if the weather
is around 72° F. Actually, it's best to build or rebuild an engine during
warm weather with the engine parts warmed at room temperature at around 72°
F.
Painting Aluminum or Cast Iron Engine Blocks and Cylinder Heads -
To get paint to stick to aluminum, the shiny and slick surface of aluminum will need to be "roughened up" with sandpaper or sandblasting so the paint (or primer paint) can grip or adhere into the microscopic scratches and crevices from the sanding or sandblasting.
To get paint to stick to a cast iron engine block (and/or cylinder head) is with the cast iron being absolutely dry. Cast iron is porous, like a sponge. It soaks up oil, and when something is painted that has oil in it, the paint may eventually peel off because the paint itself cannot soak into the cast iron so it can grip or adhere to it. To get paint (or primer paint) to stick to a used or "seasoned" cast iron block, the cast iron will need to be thoroughly heated to burn out the oil. Soaking the block in a hot tank with a chemical solution at an automotive engine machine shop will clean a lot of the oil out of the cast iron. But placing the block in a special oven furnace and rotating it against large flames will definitely burn out the oil. Then painting the inside of the block with quality paint or primer before reassembly should prevent the crankcase oil from seeping through the cast iron and making a mess on the outside. This is why Cub Cadet transaxles are painted on the inside. Kohler never painted any of their [cast iron] blocks on the inside.
Information About Using Imported/Aftermarket Engine Parts -
Most imported pistons, rings, rods and other parts from Rotary or Stens hold up VERY WELL. We've used these parts in our own equipment and pulling tractors for many years and we've sold them to our customers with no complaints whatsoever. Besides, it's how well the engine block and crankshaft are machined (cylinder bored straight, crank journal reground to OEM specs, cleanliness of the parts and work area, etc.), that determines how well and how long internal engine parts will hold up. Don't blame shoddy workmanship on shoddy parts.
What Makes an Engine "Rev Up" When Accelerated?
The throttle plate in the carburetor or throttle body (fuel injection) is nothing but an air valve. When it's opened up, the piston(s) draws more air (and fuel) in the combustion chamber(s), which builds up more air pressure (higher compression), which in turn allows the engine to produce more power and rpms. But with the engine idling, the air pressure in the combustion chamber(s) is very low. This is why and how an engine idles slowly and won't produce much power at idling speed.
Important Information About Kohler Crankshafts -
Crankshafts, rather being made
of steel or cast iron, and despite how well-balanced the rotating parts are
in a pulling engine, suffer a lot of vibration at very high rpm in a single
cylinder engine. Therefore, if possible, before purchasing a used crankshaft,
it's best to look it over for hairline cracks with a strong magnifying glass
or better yet, a powerful microscope. And as the saying goes about buying
anything off of eBay:
BUYER BEWARE! So ask for a money-back
guarantee, or you may have nothing but a piece of scrap metal on your hands.
Identifying Kohler Crankshafts -
- To identify the 10, 12, 14 and 16hp Kohler crankshafts, the 10hp cranks have a shorter stroke than the other cranks. You can compare a 10hp crank to a 12, 14 or 16hp crank by placing them side by side, and with the counter weights down, looking at the bottom part of the rod journal, the journal on the 10hp will be closer to the main journals. (3/8" of difference in stroke.)
- The 12hp crankshaft is different from the 14 and 16hp cranks because the counter weights are machined off for the lighter-weight 12hp piston assembly. NOTE: Some 10hp cranks also have the counter weights machined off like the 12hp does, but some don't.
- And the 14hp and 16hp cranks are identical in weight and appearance. Some may have a few more holes drilled into the counter weights, but that's the only difference.
- If you know your engine's exact model and specification numbers, you can go to kohlerplus.com, find the part number for the crankshaft, and then find the dimensions and specifications of the crankshaft here: CRANKSHAFT REFERENCE MANUAL. (Requires Adobe Acrobat Reader and use Google Chrome web browser for a faster download of web sites with large files.)
How to Remove Only the Crankshaft from a Kohler Engine -
-
Remove
the flywheel and anything that's on the PTO end of the crankshaft.
- Remove the cylinder head.
- Remove the oil pan.
- Remove the piston/connecting rod assembly from the engine block.
- Remove the bearing plate.
- Finally, being very gentle, bump the PTO end of the crankshaft with a 2 lb. brass head hammer or a 2-3 lb. steel hammer and wooden block to remove it from the engine block.
- And if an engine originally came with balance gears, there's no need to reinstall them. They're made of out of balance cast iron material, they serve very little purpose and they may break, possibly destroying the engine block.
Here's Something Important To Keep In Mind About A Reground Crankshaft Journal -
Sometimes as the rod journal
(crank pin) wears, it will develop a "flat spot" at a certain place when
the piston is at the ATDC position on the compression stroke. The combustion
process place the most pressure on the piston and connecting rod at this
particular point, which squeezes the oil out between the rod bearing surface
and crank journal, causing brief metal to metal contact. As this happens,
this point wears more than the rest of the journal, causing the journal to
become oval or "egg shaped." Sometimes the upper part of the connecting rod
will wear as well, but in most cases, it's the part that moves the most that
wears more, which is the crank journal.
When regrinding a journal, and if a STD size journal is not worn past .005" on the low side or on the "flat spot," then the crank grinder person can regrind it "centered" to the next undersize, which is .010", or if he gives it an extra .001" of additional oil clearance, it'll have a .011" undersize journal and the crankshaft will retain it's original stroke. But if a standard size journal is worn .006" or more, then the crank grinder can "cheat" and regrind the journal to the next undersize by offsetting the journal .006" or more in the lathe and regrind it to .010". By doing this, and depending on the amount of wear the journal had and the location of the low side or "flat spot," the crankshaft will have a slightly longer or shorter stroke. Otherwise, if the severely worn journal were to be reground "centered," it would have to go to .020" undersize, and the stock stroke will be retained. The decrease or increase of the stroke on a crankshaft with a worn STD, .010" or .020" journal can vary from .001" to .005". and as much as .010" on a STD size journal that's been reground to .020" undersize or even .015" on a STD size journal that's been reground to .030" undersize! So when a pulling club's rules state that an engine must have the stock factory length stroke, and if a crankshaft was reground, it may actually have a slightly longer or shorter stroke.
Something to take into consideration is this: Depending who regrind the crank journal undersize, the stroke can be offset more or less by .005". Some grinders like to "center" an excessively worn journal so it can be ground to the next undersize.
FYI - Oil clearance is the distance between the connecting rod bearing surface and crank journal. A thin coat of oil is supposed to keep all moving parts inside an engine from making contact with each other. If there's too little oil clearance between the rod and crank, especially in a high rpm engine, the rod will swell due to excessive heat, and then the rod will make contact with the crank and burn on the journal. If there's too much clearance, the rod will knock and possibly break at higher rpm, which could destroy the entire engine block.
Grinding a Crankshaft Journal -
Grinding a crank journal is
performed in
crankshaft grinder machine. It's actually much easier to
grind a journal on a single cylinder small engine crankshaft than it is to
grind a crankshaft with multiple journals. It takes a lot of skill and full
attention when regrinding crankshaft journals. Basically, what the crankshaft
grinder machinist needs to do is...
- Make sure the grinding stone is precision balanced, then true it up so it won't leave skip marks on the journal.
- On a single cylinder crankshaft, clamp one of the main journals in the first chuck, then clamp the other main journal in the second chuck to make sure the crankshaft is perfectly centered in the first chuck, then loosen the second chuck and move it away from the crankshaft.
- If it's a multiple journal crankshaft, perform the above with the crankshaft firmly clamped in both chucks.
- Firmly tighten the chuck(s).
- Relocate the first chuck (for a single cylinder crankshaft) or relocate both chucks (for a multiple journal crankshaft) off-center according to the crankshaft's stroke.
- Set up the dial indicator, and position it's lever on the #1 journal.
- Rotate the crankshaft slowly by hand until the lowest area on the journal shows on the dial indicator and then zero in the dial indicator.
- Relocate the first chuck (for a single cylinder crankshaft) or relocate both chucks (for a multiple journal crankshaft) off-center according to the crankshaft's stroke.
- If it's a multiple journal crankshaft, position the steady rest in the center main journal to prevent flexing of the crankshaft when grinding.
-
Slowly and very carefully grind
each journal to the next undersize until it's within .0001" of specs. But
the grinder machinist needs to stop midway of grinding and carefully measure
the journal(s) with a
digital micrometer (a
dial or digital caliper are not as accurate) from time
to time so the journal(s) will grind within specs. Once metal is removed,
it's hard to replace. If a journal is ground undersize too much, it can be
reground to the next undersize, or if it's already reground to the maximum
undersize, it can be welded up 360°, then reground to STD size again,
or to the undersize of the other journals. But welding a journal and then
regrinding it can be very expensive! And the crankshaft's stroke may not
be the same.
- Back the stone away, and finish polishing the journal with a crankshaft polisher. The polishing process will remove the roughness of the grinding stone and about .0001" of metal until the journal is within specs.
The standard (STD) size rod journal (crank pin) on Kohler's K241/M10 (10hp),
K301/M12 (12hp), K321/M14 (14hp) and K341/M16 (16hp) flatheads, K361 (OHV
18hp) and the M20, MV20 twin cylinder engines measures 1.500" on the "high
side", and 1.499" on the "low side" (maximum wear limit). If an engine is
going to run no faster than 4,000 rpm (either for general yard work or
competition pulling), then it should be safe to have a worn rod journal reground
on the high side. The grinder person will grind the journal(s) as follows:
- .010" undersize, which will measure 1.490" for a .010" undersize aluminum bearing surface connecting rod or a connecting rod with .010" bearing inserts.
- .020" undersize, which will measure 1.480" for a connecting rod with .020" bearing inserts.
- .030" undersize which will measure 1.470" for a connecting rod with .030" bearing inserts.
But when having a worn rod journal reground for an engine that's going to run at higher rpms or at wide open throttle for pulling competition, it'll be a good idea to indicate this to the crank grinder person by writing on one of the counterweights the words LOW SIDE with a bright-colored paint marker (TEXPEN®). The grinder person will then grind the journal(s) as follows:
- .011" undersize, which will measure 1.489" for a .010" undersize aluminum bearing surface connecting rod or a connecting rod with .010" bearing inserts (recommended).
- .021" undersize, which will measure 1.479" for a connecting rod with .020" bearing inserts.
- .031" undersize which will measure 1.469" for a connecting rod with .030" bearing inserts.
- The additional .001" of [oil] clearance is to prevent overheating and scoring of the plain aluminum connecting rod or bearing inserts and/or rod journal at high rpms.
NOTE: If the word RACE is written on a crank for additional oil clearance, some crank grinders will still grind a journal on the low side and add an additional .001". Which will make the journal .012", .022" or .032" undersize. So RACE should only be used on a journal that's going to be reground on the high side, which will provide the same clearance as having a journal reground on the low side. And by the way - the additional .001" of clearance (with either LOW SIDE or RACE) will not cause the rod to make a knocking sound. Click HERE for Complete Kohler Single Cylinder Engine Specifications and Tolerances.
The heat-treating or hardening
process that Kohler use on the rod journal area obviously goes deep into
the crank. Because it's been proven that when the journal is ground for an
undersize bearing, a .010", .020" or even a .030" undersize bearing can be
used with no problem. Myself and many other pullers use undersize bearings
in our pulling tractors, and I have no problems with the crank journal wearing.
Heck, I've been using a .020" undersize bearing with the same crankshaft
in our 30 c.i. tractor for 5 years and in about 75 pulls, and the crank journal
hasn't worn at all. Most crank journals wear because of dirty motor oil or
the wrong viscosity of oil is used. Not because of "soft metal" in the journal.
Actually, the bearing material is not supposed to make contact with the crank
journal. They're supposed to be kept separate by clean motor oil. And as
far as cast iron Kohler crankshafts breaking is concerned, an undersize journal
shouldn't make a cast crank break. I've always seen them break next to the
journal, not in the journal area. As with anything, crankshafts break because
something makes them break. Either out-of-balance parts, dirty flywheel
taper/crankshaft taper or a manufacturing defect makes a crankshaft break.
By the way, a crank journal that's been turned .030" undersize will help to produce slightly more rpm and horsepower because there's less bearing surface to cause friction. Some NASCAR engineers do this to their racing engines. It works.
If you have a crankshaft that's made for a special purpose, and it has a worn .030" journal, and that particular crankshaft is no longer available, well, the journal can be welded up and reground back to STD size. Here's one place who can do this for you: Big 2 Engine Rebuilders, Inc., 3214 25th Ave., Gulfport, MS 39501-5909 Phone: 228-863-5425 FAX: 228-868-8728. Ask for Pete Bloss.
Stroking a Stock-Stroke Crankshaft -
Virtually any machine shop that
regrind crankshafts can weld up the rod journal and regrind it to give it
a slightly longer stroke. But keep in mind if thinking of doing this, that
if using a stock-length connecting rod with a stock compression-height piston,
the piston will pop out of the cylinder half the distance that was added
to the stroke on the crank journal. The piston could hit the cylinder head.
Also, grinding the center of the [stock] camshaft may be required for clearance
of the connecting rod swing due to the longer stroke. And notching of the
cylinder wall on either side of the rod swing for clearance may be required
to prevent the rod from striking the lower part of the cylinder wall. Finally,
the oil dipper on the rod cap may need to be shortened to prevent it from
hitting the bottom of the oil pan.
But if building a stock engine at 4,000 rpms for more power and torque, it'll be better and less cost effective to use a stock stroke crankshaft, and install a reground low-rpm torque cam to give the engine a little more muscle. Performing a performance valve job to increase the air flow and milling of the head will help the engine to pump out a few more ponies, too.
Advertisement:
If you need any of the services performed or items listed
below Ê, please contact A-1 Miller's
Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136
USA |  Phone: 1-573-875-4033.
Please call Monday-Friday (except Holidays), 9am to 5pm, Central time zone.
If no answer, please try again later. (When speaking with Brian, please
be patient because I stutter.)
 Fax: 1-573-449-7347.
 E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
|
Crankshaft Repairs -
|
|
| Reconditioned OEM Kohler Crankshafts - [When
available.]
Available for Kohler engine models K241/M10
(
|
|
 Main Crankshaft
Radial Ball Bearings for Kohler K-series and Magnum cast iron block engine
models K141 (6¼hp), K160 (6.6hp), K161 (7hp) and K181/M8 (8hp). Heat
treated. These are specifically designed to provide maximum performance through
precise ball implement selection. Aftermarket bearing packed with fresh grease
from the factory. Dimensions: 1.18" i.d. x 2.44" o.d. x .62" width. See note
below Ê. NOTE: If yours have more
than .005" of play (wear), then it needs to be replaced. Kohler part
# 231625-S.
8 Ball Main Crankshaft Radial
Bearings for Kohler K-series and Magnum cast iron block engine models K241/M10
(10hp), K301/M12 (12hp), K321/M14 (14hp), K341/M16 (16hp) and K361 (18hp
OHV). Heat treated. These are specifically designed to provide maximum
performance through precise ball implement selection. Aftermarket bearing
packed with fresh grease from the factory. Good for general yard and garden
or high-performance use. At high rpms or at wide open throttle, bigger balls
run cooler which create less rolling resistance than a bearing with smaller
balls. Dimensions: 1.57" i.d. x 3.54" o.d. x .90" width. See note below.
Ê NOTE: If yours have more than .005"
of play (wear), then it needs to be replaced. Kohler part # 235376-S.
NOTE: With the main bearings removed from an engine, and if all the oil is cleaned from the bearings, allowed to thoroughly dry, and then the bearings are spun by hand, and if the bearings isn't worn much or at all, they might feel "rough" and make a rattling sound. This rattling sound isn't necessarily because the bearing is worn. The noise is caused by the balls running dry on the races because there's no oil to separate them. They're simply making metal to metal contact. Try applying a small amount of motor oil to the balls/races and then spin them. They should now be a lot quieter. The same thing will happen with new radial ball bearings. By the way - Most main bearings in a Kohler engine will wear extremely little, if any at all, and usually don't require replacing. Although some main bearings will wear (which is obvious), and need to be replaced. And excessively worn main bearings will make a rumbling noise and the engine will have a more than-usual-vibration. |
|
 All-metal
self-locking flywheel retaining nuts for threaded stud on end of K-series
and steel crankshafts. Guaranteed to stay tight! IMPORTANT: Apply thin
coat of motor oil on threads of crankshaft before installing nut then torque
each at 65 ft. lbs.
|
 Flywheel retaining bolt for
threaded hole in end of crankshaft. Each are grade 8, 1-1/2" long. Torque
at 40 ft. lb. Replaces Kohler part # 25 086 253-S.
|
 Steel Adapter
Step-Washer for mounting Cub Cadet aluminum clutch hub with 5/8" center hole
to Kohler Magnum crankshaft with a 3/8" bolt. A must to center hub and prevent
hub breakage! $8.00 each, plus shipping & handling. |
|
 Steel Rectangular
Flywheel Key for early Kohler K-series engine models K241, K301, K321 with
the 8" diameter flywheel. Dimensions: 3/16" wide x 1/4" tall x 1-3/8" long.
OEM Kohler part # X-366-1-S.
Aluminum Rectangular Flywheel Key for Kohler K-series engine models K141, K160, K161, K181, K241, K301, K321, K341, K361 and Magnum M8. Made of 6061 alloy; medium-grade hardness aluminum. Dimensions: 3/16" square x 1-3/8" long. Replaces Kohler part # X-366-1-S.
Aluminum Square Flywheel Key for Kohler K-series engine models K141, K160, K161, K181, K241, K301, K321, K341, K361 and Magnum M8. Made of 6061 alloy; medium-grade hardness aluminum. Dimensions: 3/16" square x 1-3/8" long. Replaces Kohler part # X-286-17-S.
|
|
Once installed and in
operation, there is no warranty or guarantee of any kind on crankshaft
regrinds.
10hp), K301/M12 (12hp), K321/M14
(14hp), K341/M16 (16hp) or K361 (18hp OHV). These cast iron cranks are genuine
Kohler, used and in excellent condition. They have either a 1" or 1-1/8"
diameter x 3-1/2" long keyed PTO shaft. They have good gear teeth and may
have a worn or unworn connecting rod journal in either STD size or undersize.
Which can be reground to .010", .020" or .030" undersize. Although .030"
is rare, it's still very safe to use. FYI - To be honest, these are old,
used crankshafts. So if you need one with an unworn STD size rod journal,
you'd probably have just as good a chance of winning the lottery than finding
a used Kohler K-series or Magnum single cylinder crankshaft with an unworn
STD size journal. And if you're going to use a pulley, clutch, etc., on the
PTO end, then I will need to know the exact dimensions of the PTO end on
your crankshaft so I can match it to one that I may have in stock. For accuracy,
measure the length from the oil seal shoulder out. If you know your engine's
exact model and specification numbers, go to
Extra Thick Steel Washers for retaining flywheel and/or Cub
Cadet aluminum clutch adapter hub to flywheel (a must to prevent hub breakage!),
or use as a safety washer w/grade 8 bolt on PTO end of crankshaft.
Steel Square Flywheel Key for
Kohler K-series engine models K141, K160, K161, K181, K241, K301, K321, K341,
K361 and Magnum M8. Dimensions: 3/16" square x 1-3/8" long. Kohler part #
X-286-17-S.
Steel Woodruff Flywheel Key
for early Kohler engine models K160, K161, K181 and later 10-16hp K-series
and all Magnum engines. 3/16" wide x 1" long. Kohler part # X-46-3-S.
About Crankshafts Breaking at High RPMS -
A cast or billet steel crankshaft should survive as high as 7,000 rpms for a long time if they've been precision-balanced to the connecting rod and piston assembly. Some cast cranks break, and steel crankshafts are prone to breaking, too. When they do break, it's usually due to: being in an engine that broke the connecting rod and the rotating assembly came to a "sudden stop", and the flywheel kept wanting to spin, but cracked the crank instead; an out of balance flywheel (steel flywheels should be precision-balanced, too); and/or an out of balance starter pulley on the PTO end (which should also be precision-balanced). An out of balanced flywheel or pulley will cause the crankshaft to flex a few thousands of an inch at high rpms. When they flex, this causes metal fatigue, which creates a microscopic crack next to the rod journal, and they eventually break. Kind of like bending a piece of wire back and forth by hand, until it eventually breaks. I heard that the Magnum crankshafts are tougher than the early K-series cranks when precision-balanced. And when a crankshaft breaks at high rpms, it can also break a cast cam or bend a billet steel cam, which could crack the engine block at the cam pin on the flywheel side.
If a stock engine runs with a "hunting" sound, and the governor lever moves side to side while running at around 3,600 or 4,000 rpms, and if adjusting the carburetor or adjusting the rpms doesn't fix the problem, then perhaps the governor gear/flyweights assembly is worn on its stub shaft, or the shaft itself is worn. This will cause the governor gear to wobble around on its shaft, which will cause the governor to oscillate. And the engine will run erratic. To fix this problem, the governor gear and shaft must be replaced with new ones, or a cast iron governor gear. (Nylon governor gears are known to wear more often than cast iron ones.)
How to Remove and Replace the Governor Gear/Flyweights Assembly in a Single Cylinder Kohler Engine -
- Remove the internal parts of the engine (mainly the crankshaft and camshaft).
- Remove the governor gear retaining screw (the Phillips head screw that's on the outside of the block).
- The governor gear can now slide off the stub shaft.
-
If the engine is going to be rebuilt
and the block thoroughly cleaned, be sure to remove and save the small thrust
washer that's on the governor gear's stub shaft! This special washer is
made of either hardened steel or bronze for durability. A lot of people are
not aware of this washer and it usually falls out of the block and gets lost
while cleaning inside the block.
- Install the new governor gear assembly in reverse order of removal.
How to Replace a Worn Governor
Stub Shaft (Governor Pin) in a 6¼hp-16hp Kohler Engine -
- Remove the governor gear as described above È.
- Remove the cam gear cover and through the cover opening, use a 5/16" steel rod with a blunt end and medium size hammer to drive the welch plug from the block.
- Going through the welch plug hole opening, use a 5/16" steel rod with a concaved end (depressed center) and medium size hammer to drive the stub shaft from the block.
- Fabricate a driver from a 5/8" diameter solid steel rod having a 3/8" diameter x 3/8" deep drilled hole in one end to install the new stub shaft in the hole. Allow the stub shaft to extend 3/8" from the block.
- Place the welch plug over a 7/8" socket and use the hammer to depress the center so the plug will become concaved (depressed center).
- Apply Clear RTV Silicone Adhesive Sealant around the welch plug counterbored hole and install the welch plug in the hole with the depressed center facing upward. Use the hammer to flatten the welch plug so the diameter will expand and fit tight in the counterbore hole. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for two reasons: being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean-looking repair job. It can't be seen between the parts.
Nylon VS Cast Iron Governor Gear Assemblies -
The most popular Kohler governor gear assembly nowadays for competition stock
garden tractor pulling are the ones that's made of cast iron. These are no
longer made or available from Kohler or any other source. They were used
in the 4hp, 6¼, 7hp, early 8hp, early 10hp and 12hp K-series Kohler
engines 'til the late 1960s. It's impossible to tell if an engine has a metal
governor gear by looking at it from the outside. The only way of knowing
for sure is remove the oil pan and look at it from inside.
There's really nothing special about the cast iron governor gear, except when the governor linkage is disconnected, they can withstand very high rpms and won't explode (break apart) like the nylon governor gears sometimes do. The reason the cast iron ones are so popular nowadays among stock pullers is because some pullers like to compete in two separate classes, one class that has an engine rpm limit of around 4,000± and another class with a higher rpm limit, or open rpm. Consider this: The governor gear spins 1.25 times faster than the crankshaft. This means at 4,000 rpm, the governor gear spins at 5,000 rpm. At 6,500 rpms, it spins at 8,125 rpms! And when using a nylon governor gear, don't worry, as long as the governor linkage is adjusted correctly, it should hold up just fine in an engine that will never operate above 4,000 rpm. The cast iron governor gear will fit all Kohler K-series and Magnum 4hp-16hp flatheads, 18hp K361 OHV single cylinder cast iron block and the KT-series and Magnum flathead twin cylinder engines. |
 |
Advertisement:
| If you need any of the parts listed below
Ê, please contact A-1 Miller's Performance
Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
1-573-449-7347. E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
|||
 Nylon
Governor Gears. Good for up to 4,000 rpm. OEM Kohler part # A-235743-S.
|
Cast Iron Governor
Gear. Good for above 4,000 rpm up to
wide
open throttle. Will not explode or flex at high rpms like the nylon governor
gears sometimes do. OEM Kohler part # A-237031. (Discontinued from Kohler.)
|
||
  Governor Gear Stub Shafts for Kohler engine models K141
(6¼hp), K160 (6.6hp), K161 (7hp), K181/M8 (8hp). Dimensions: 3/8" diameter
x .625" long. Each is press-fit into block. Kohler part # 230125-S.
Governor Gear Stub Shafts for Kohler engine models K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp), K341/M16 (16hp), K361 (18hp OHV) and all KT-series & Magnum twin cylinder flathead engines. Dimensions: 3/8" diameter x .815" long. Each is press-fit into block. Kohler part # 235125-S.
|
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 New hardened steel
thrust washer for nylon or cast iron governor gears. Kohler # 237022-S.
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 Governor Cross
Shafts for Kohler engine models K141 (6¼hp), K160 (6.6hp), K161 (7hp)
and K181/M8 (8hp). New shaft includes thrust washer. The lever on these rarely
break. NOTE: Before installing, apply clean motor oil on shaft for smooth
governor action and less wear to shaft and/or bushing. OEM Kohler part
# 230540-S.
 Governor Cross Shafts for Kohler
engine models K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp), K341/M16
(16hp) flatheads, K361 (18hp OHV). New shaft includes steel thrust spacer.
NOTE: Before installing, apply clean motor oil on shaft for smooth governor
action and less wear to shaft and/or bushing. OEM Kohler part # A-235256-S.
|
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 Bronze Governor
Shaft Bushing for all Kohler engine models K90 (3.6hp), K91 (4hp), K141
(6¼hp), K160 (6.6hp), K161 (7hp) and K181 (8hp) w/spec # 30100-30848
and various M8 (8hp) engines with V-shaped/coiled governor spring under bushing.
NOTE: When ordering, please specify engine model and specification
numbers. And before installing bushing, apply clean motor oil on shaft
for smooth governor action and less wear to shaft and/or bushing. OEM
Kohler part # 230476-S.
|
|||
Steel Thrust Washer for governor
cross shaft above È. Kohler part #
X-25-58-S.
Steel Thrust Spacer for governor
cross shaft above È. Kohler part # 25
112 17-S.
Bronze Governor Shaft Bushing
for Kohler engine model K181 (8hp) w/spec # 301000-301045, and various M8
(8hp) engines with extension governor spring. NOTE: When ordering,
please specify engine model and specification numbers. And before installing
bushing, apply clean motor oil on shaft for smooth governor action and less
wear to shaft and/or bushing. OEM Kohler part # 41 158 02-S.
Bronze Governor Shaft Bushing
for all Kohler K-series and Magnum engine models K241/M10 (10hp), K301/M12
(12hp), K321/M14 (14hp), K341/M16 (16hp) and K361 (18hp OHV). NOTE: When
ordering, please specify engine model and specification numbers. And
before installing bushing, apply clean motor oil on shaft for smooth governor
action and less wear to shaft and/or bushing. OEM Kohler part # 235476-S.
Bronze Governor Shaft Bushing
with Neoprene Rubber Seal installed in machined counterbore to keep dirt
out (which wears the bushing) and prevent oily mess on side of engine. Seal
fits snug on shaft and in bushing, and has no effect with operation of governor
whatsoever. For Kohler engine models above
È with bushing # 230476-S, 41 158 02-S
or 235476-S. NOTE: When ordering, please specify part number of bushing
or engine model and specification numbers. And before installing bushing,
apply clean motor oil on shaft for smooth governor action and less wear to
shaft, seal and/or bushing. An innovative concept by Brian
Miller, because nobody else advertise this part.
NEVER USE
GASOLINE OR A HIGHLY FLAMMABLE LIQUID TO CLEAN YOUR PARTS!
Gas cleans good, but it's extremely flammable, making it too dangerous to
handle. The best (and safest) way to clean an engine block and its parts
for rebuilding is to wash all parts with cleaning solvent (or
mineral
spirits, also known as
paint
thinner). Paint thinner is also known as or can be used as cleaning solvent
for oily or greasy engine or mechanical parts. Personally, I've always used
paint thinner to clean my engine parts.
Another product that works great for cleaning engine parts is Greased Lightning® Multi Purpose Cleaner. But use caution when using this product! It will remove the paint also. So it's best to use it on bare metal or parts that need repainting.
For stubborn or caked-on grime, use a heavy duty oven cleaner, such as EASY-OFF® or equivalent. (Use the fume-free brand so you can breath.) Just spray the parts thoroughly, let set for 30-45 minutes, then blast the grime and debris off with a high pressure water washer. Pressure from an ordinary garden hose just won't cut it. After cleaning, blow dry the parts and be sure to coat the bare metal with oil so they won't rust. If oven cleaner won't work, take the cast iron and steel parts to an automotive machine shop and have them "hot tanked" and have the aluminum parts sandblasted. I don't suggest sandblasting cast iron engine blocks or related parts because some of the sand can become lodged inside the engine and come loose when the engine is in operation, causing severe internal engine wear. Personally, I just coat the parts with oven cleaner and then blast the dirt off with my 1,000 psi water pressure washer.
Paint thinner can also be used to dry motor out oil that's spilled on a concrete floor. Just pour some thinner on the oil, use an old broom to thoroughly mix the thinner with the oil, and eventually, the oil will dry with no signs of it ever being on the floor.
How to Remove Surface Rust from a Cast Iron Engine Block or Cylinder Head -
Use a heavy duty bathroom toilet bowl cleaner. Most of them will remove rust and scale. If it reads on the label that it will remove rust, then that's the one to use. This is what I use on some of the blocks I get in that need cleaning. I just apply the cleaner on the block, allow it to soak for about 30 minutes and then blast it off with my 1,000 psi water pressure washer. The rust and grime comes right off!
How to Get More Power Out of a Stock Engine -
It takes three things to make an internal combustion engine run: compression,
carburetion and ignition. There's three things that make an internal combustion
engine run: Carburetion, compression and ignition. Fuel needs to get to the
carburetor and then into the engine. The engine needs to have adequate
compression to fully compress the air/fuel mixture to make power. And the
ignition needs to be strong enough to ignite the air/fuel mixture. The ignition
timing must also need to be set correctly to ignite the air/fuel mixture
precisely at 20° BTDC to take full advantage of the exploding gases.
Actually, it takes four things to make an engine run, including the starting
system. If an engine won't start or if it's hard to start, and it has adequate
compression, the carburetor and ignition seems to be working fine, then the
only thing left is the starting system. Perhaps the starter motor or battery
is going bad. They probably appear to be operating normal, but maybe one
or the other isn't cranking the engine over fast enough to produce adequate
compression to start the engine. I've seen this happen a few times. But if
the compression, carburetion or ignition is weak or defective, power will
be decreased dramatically. When checking for loss of power, always check
the following things:
ü Carburetion
is when an adequate amount of fuel and air mixture enters an engine
smoothly.
ü Check the
ignition timing. If the timing is retarded or
over advanced, the engine will lose power and run sluggish. Check for a
worn points lobe on the camshaft,
too.
ü Compression is when the air/fuel mixture
is adequately pressurized in the combustion chamber on the compression stroke.
The secret to gaining more horsepower and torque is increase the compression
ratio and improve the air flow in and out of the combustion chamber.
ü Another way to gain more power from the
high rpm is to install a special camshaft along
with larger diameter valves, performance valve
job, stiffer valve springs and porting/polishing
the intake and exhaust runners.
ü Apply
J-B Weld (apply at room temperature, allow to fully
cure in 24 hours) inside the intake port and smooth it so the air will flow
without any restrictions into the combustion chamber. This works great. But
before applying the J-B Weld, make sure the port is absolutely clean or the
J-B Weld will not bond to the engine block.
ü and a few other things that's mentioned
elsewhere in my pulling tips web sites.
FYI - When everything that's mentioned here is performed to an engine, it should produce maximum power. But if just a few things are performed, the power will be increased, but not to the maximum. For example: if the valves are reworked for more airflow, then the intake and exhaust runners would also need to be enlarged, and the carburetor would need to be bored to take full advantage of the maximum airflow. But if the intake runner isn't enlarged, this would create a "bottle neck," and air will be restricted. The same goes for the valves and carburetor. Also, if a cam with more duration is installed, then the valve and air intake system would need to be maximized to take full advantage of the performance camshaft. But if just the cylinder head is milled, and nothing else is done to the engine, this alone should add a few ponies to an engine. The same goes when just popping the piston out of the cylinder. Each time a performance thing is done to an engine, power output will be increased. But if a series of things are performed, such as maximizing the air intake system, they can work together for better engine performance.
When it's time to put more muscle in an engine...
In order for an engine to turn at extremely high rpm (6,000+), the compression ratio and air flow in and out of the combustion chamber must be increased to the maximum. The secret to increased engine performance is to get as much air (and fuel) into the combustion chamber, and get it out as quickly as possible. (Remember - engine performance is entertainment to the spectators.) For the compression ratio to be increased, the air entering the combustion chamber must be squeezed as tight as possible.
The only things that can cause an engine to overheat and loose power are as follows:
- Clogged cooling fins or broken fins on the flywheel
- Too high compression ratio for the grade of gas being used
- Ignition timing advanced too much
- Lean fuel mixture
- Vacuum leak at the carburetor, which will also cause a lean fuel mixture.
Get Maximum Horsepower and Torque from a "Basically Stock" Kohler 10-16hp K-Series or Magnum Engine -
Approximately 48% more horsepower and torque can be produced from a basically "stock" single cylinder flathead Kohler engine. This means that approximately 15hp can be produced from a 10hp, 17hp from a 12hp, 20hp from a 14hp and 23hp from a 16hp governed engine at 4,000 rpm (the factory setting of maximum rpm for virtually all small gas engines, including all of Kohler engines is 3,600) on Premium gasoline! And if the majority of the fins are removed from the flywheel, or if a steel flywheel is used, this will add about 3-4 more hp at 4,000 rpm per engine! Also, about 10% to 13% more power can be produced with E-85 or methanol fuels! Click here for information regarding E-85 fuel. The above È figures was computed using Mr. Gasket's DeskTop Dyno computer application. (Do a search on the Internet for this application.) And even more power can be produced above 4,000 rpm! But be sure to install a billet steel flywheel, connecting rod and scatter shields whenever running an engine above 4,000 rpm! The compression ratio must be increased in order to increase the power output. Click here for references to various compression ratios. After modifications have been made, the increase in power will definitely be noticeable!
For pulling competition only, remove or disable the operation of parasitic accessories from the engine (which robs horsepower and causes drag on the engine), such as the starter/generator or alternator charging system, and including reducing the height of the fins by about 3/4 on the flywheel. Click here to learn how to do this.
Advertisement:
| If you need your crankshaft and piston/rod assembly and/or flywheel
precision dynamically balanced, please contact A-1 Miller's Performance
Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
1-573-449-7347. E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
Precision, Dynamic Spin-Balancing Service -
|
And depending on battery drainage and need for recharging, to be precise, and with the engine running at 3,600 rpm, the generator part of the starter/generator unit or alternator stator use about 3/8hp (of engine power) when it recharges a fully discharged battery at full 15 amps; about 5/8hp at full 20 amps; and about 7/8hp at full 30 amps. But if the battery doesn't need much recharging, the charging system draws less hp from the engine. I know this small amount isn't much, but every hp counts in competition pulling. So to reserve this power for pulling, disconnect the generator or alternator from charging the battery (and powering other accessories as well) simply by splitting the wire that connects to the FIELD terminal (the smaller wire and terminal) on a s/g unit and splitting the wire that connects to the center terminal on the voltage rectifier/regular of an alternator system. Then connect an ordinary OFF/ON toggle switch in that wire or circuit to turn off and on the charging current. And it'll be best not to spin the s/g when pulling. Being it has radial ball bearings, the excessive spinning won't hurt it. But being the V-belt causes drag, depending on belt tension, it can use up to 2hp of engine power just to spin it. This is also power that can be put to the rear tires for pulling. Besides, wouldn't it be better to spin the tires than the starter/generator? So to disengage the s/g belt, install threaded studs with locknuts on the s/g bracket and install a heavy spring on the s/g so it'll remain close to the engine. To crank the engine, install the belt on the pulleys, then pull out on the s/g with a fabricated handle to tighten the belt. After the engine starts, release the s/g and flip the belt off. But use caution doing this for an obvious reason!
Briggs and Stratton, Tecumseh, Onan and Kohler's cast iron block 7hp and 8hp, and the twin cylinder flathead engines are all somewhat limited on what can be done to boost their horsepower and torque. These engines are built from the factory to produce as much power as they possibly can, and still run safely on low octane gasoline. Therefore, very few modifications can be perform to help increase the power output. The only alternative is to use a bigger engine.
The increase in the compression will cause the combustion chamber to operate at a higher temperature. If low octane gas (87 octane) is used, and because low octane gas burns more rapidly than high octane gas, it'll burn hotter in a high compression engine, causing the piston and rings to overheat and wear out much sooner. Therefore, high octane gas (at least 91 octane [Premium]) must be used in a high compression engine because it burns slower and it maintains a cooler operating temperature within the combustion chamber. It'll help the engine last longer plus the high octane gas will help to produce more power. Also, it's safe to use just ordinary unleaded [high octane] gasoline with no additives (except what's already been formulated with the gasoline at the pump). Premium gasoline is the highest octane automotive gas you can get at your local filling station or convenience store.
High compression engines naturally operate at a higher operating temperature. So when using low octane gasoline (87 octane rating) in a high compression engine, the octane of the gas is reduced by 1 point for every 10º above the operating combustion chamber temperature that it is formulated for. This will cause the gas to burn faster and cause the engine to lose power. "Detonation" (pounding of the piston) could also occur. When trying to restart an overheated high compression engine on low octane gas, what is happening is the gas is burning quickly and entirely in the combustion chamber, and producing expanding heat before the piston reaches TDC, driving the piston back down in the cylinder before it reaches TDC. It'll cause the engine to "runt, runt" or momentarily make the crankshaft rotate in the opposite direction (but the weight of the flywheel prevents this from happening). Overheating could also crack the [cast iron] cylinder, shrink the piston, burn a hole in the piston (detonation) and weaken the expansion of the piston rings. Methanol fuel has an octane rating of 135. This is why methanol works best in high compression engines.
If you have a stock, low compression engine, then it won't benefit whatsoever from using high octane fuel. All it'll do is waste fuel (some of the fuel will go unburned and exit out the exhaust) and the engine won't develop full power, even with advanced timing. So it's best just to use low octane fuel for best performance.
In an ordinary engine that's built-to-factory-specs (with no modifications), it's OK to use just 87 octane gasoline. If you were to use high octane gas in a low compression engine, you'll just be wasting money and gas. Because some of the gas will go out the exhaust unburned, with no increase in horsepower whatsoever.
The initial setting for proper operation of the governor for stable engine speed is first loosen the clamp nut on the governor lever and rotate the shaft counterclockwise with the throttle in the full throttle position. Then tighten the nut. After you start the engine, run it a full (governed) speed and select the hole in the governor that allows the engine to run at 3,600 rpm.
A nylon governor gear works best if an engine will never run above 4,000 rpm. But if you're going to pull competitively with an engine and disconnect the governor to run the engine at wide open throttle, then it's best to install a cast iron governor gear. Because nylon could explode due to the increased rpm.
And if you've heard that by drilling a hole through the flyweights on the governor gear to lighten them will improve engine performance, well, first of all, the flyweights are made of extremely hard material for obvious reasons. I tried, and there is no way to drill a hole through them. It's even hard to grind metal off of them. Besides, lightening the flyweights will not help in engine performance whatsoever. All it'll do is allow the engine to rev up more, that's all.
If you want to do away with the governor, you must remove it entirely from inside the engine block. Otherwise, at high rpm, the flyweights that's attached to the governor gear (which is called the "governor spool") could cause the nylon spool to explode. Or, you could disconnect the governor link from the carburetor and wire the arm to the exhaust pipe. This will prevent the governor spool from being damaged at high rpm. But then you must fabricate a throttle linkage of some kind to activate the throttle on the carburetor. For safety reasons, install a steel flywheel and crankcase side shields on an engine with no operating governor!
If you need even more power, remember the old saying? "There's No Substitute for Cubic Inches!"
If you're running a 10hp (K241)
Kohler engine in a class that allows up to a 12hp engine, there's no need
to go out and acquire a 12hp block, and then have all the fancy machine work
that was originally done on the 10hp block. Instead, a 10 can be easily converted
into a 12 by having the cylinder bored for a 12hp piston assembly, a 12,
14, 16 or 18hp connecting rod, and a 12hp crankshaft.
NOTE: Some 10hp Kohler engine blocks have K301
embossed in the casting on the PTO
end. These blocks have a thicker cylinder wall and can be safely bored for
a 12hp piston (even up to .030" oversize), without making the cylinder wall
too thin. They cannot be bored for a 14hp piston though.
The K301 blocks with a 10hp bore can be safely bored for use with a 12hp piston. The K301 blocks are actually a 12hp block with a 10hp bore. There's nothing special about this blocks, except for the thicker cylinder wall. They weren't used in any "heavy duty" specific purpose either. What happened is on the production line at Kohler, when they ran out of 10hp blocks, they grabbed a bunch of 12hp blocks and bored them for use with a 10hp piston to finish the production of a bunch of 10hp engines. And not all Kohler blocks that have the K301 characters are actually 10hp blocks. Some are bored for a 12hp piston assembly (3.375" STD size bore) and therefore, are a 12hp block. The ones that are bored for a 10hp piston assembly (3.250" STD size bore) have a thicker cylinder wall and therefore, are a 10hp block. To determine which block is which, the diameter of the cylinder bore needs to be accurately measured.
How to Create a 25.7, 27.7, 31.6 CID Engine or a Hybrid Kohler Engine Model K261, K281 or K321 - An innovative concept by Brian Miller, because nobody else advertise this.
To create a 25.7, 27.7, 31.6 CID engine or a hybrid Kohler engine model K261,
K281, K321, use a K301/M12 (12hp), K321/M14 (14hp) or K341/M16 (16hp) engine
block and piston/rings assembly respectively, a stock K241/M10 (10hp) connecting
rod or a 5.558" (10hp) billet rod with a 1.500" journal hole, and a K241/M10
(10hp) crankshaft. This will create a de-stroked 12hp, 14hp or 16hp Kohler
engine. The model K261 will use a 12hp block; the K281 will use a 14hp block
and the K321 will use a 16hp block.
If the K261 is built to the max at 4,000 rpm with reworked stock size valves, ported, quality performance torque cam and a bored-out 1.2" carburetor, it'll produce about 16½hp and 23 ft. lb. of torque at 4,000 rpm. And if built to the max at wide open throttle with reworked stock size valves, ported, big performance cam and bored-out 1.2" carburetor, it'll produce about 26hp at 7,500 rpms and 22 ft. lb. of torque at 6,000 rpm. If the K281 is built to the max at 4,000 rpm with reworked stock size valves, ported, quality performance torque cam and a bored-out 1.2" carburetor, it'll produce about 22hp and 28 ft. lb. of torque at 4,000 rpm. And if built to the max at wide open throttle with reworked stock size valves, ported, big performance cam and bored-out 1.2" carburetor, it'll produce about 30hp at 7,000 rpms and 25 ft. lb. of torque at 6,500 rpm. If the K321 is built to the max at 4,000 rpm with reworked stock size valves, ported, quality performance torque cam and a bored-out 1.2" carburetor, it'll produce about 25hp and 33 ft. lb. of torque at 4,000 rpm. And if built to the max at wide open throttle with reworked stock size valves, ported, big performance cam and bored-out 1.2" carburetor, it'll produce about 36hp at 7,500 rpms and 30 ft. lb. of torque at 6,000 rpm. Here's how to make it happen:
|
For installation of bearing
inserts in the connecting rod, the big end will need to be bored .070" offset
toward the wrist pin hole so the piston will come flush
with the top of the block, or it can be bored .050" offset toward
the wrist pin hole for a .020" piston pop-out. NOTE: If boring
the rod didn't remove metal from the entire circumference of the hole, roughen
the uncut portion with 60 grit sandpaper, apply
How to Create a 27 CID Engine or a Hybrid Kohler Engine Model K271 (Stroker 10hp Engine) - An innovative concept by Brian Miller, because nobody else advertise this.
To create a 27 CID engine or a hybrid Kohler engine model K271, use a K241/M10
(10hp) block with a 10hp piston/rings assembly, a 12hp, 14hp, 16hp [flathead
engine] connecting rod, an 18hp OHV ALCOA rod or a 5.7" billet rod, and a
12hp, 14hp, 16hp flathead or an 18hp OHV engine crankshaft. This combination
will create a 27 cubic inch engine, a hybrid model K271, or a "stroker 10hp
engine." With a STD size [10hp] piston, this engine will have a 3.250" bore
and 3.250" stroke, resulting in a 26.96 cubic inch displacement engine. For
strength and durability, especially if it's built to the max, it's best to
use a model K241 (10hp) block with K301
embossed on the PTO end, like the one pictured above
È. These particular blocks have an extra
thick cylinder wall.
If this engine is built to the max at 4,000 rpm with reworked stock size valves, ported, quality performance torque cam and a bored-out 1.2" carburetor, it'll produce about 19hp and 25 ft. lb. of torque at 4,000 rpm. But if built to the max at wide open throttle with reworked stock size valves, ported, big performance cam and bored-out 1.2" carburetor, it'll produce about 29hp at 7,000 rpm and 22 ft. lb. of torque at 6,000 rpm Here's how to make it happen:
|
For installation of bearing
inserts in the connecting rod, the big end will need to be bored .080" offset
toward the oil dipper so the piston will come flush
with the top of the block, or it can be bored .100" offset toward
the oil dipper for a .020" piston pop-out. If boring the rod
didn't remove metal from the entire circumference of the hole, roughen the
uncut portion with 60 grit sandpaper, apply
How to Build a 30 Cubic Inch (NQS Outlaw) Pulling Engine -
To build a "somewhat" competitive 30 cubic inch pulling engine, acquire a
newer 12hp Kohler block with a large intake port, have the cylinder bored
to .050" oversize for a 3.425" aftermarket (J&E or Arias) piston/rings
assembly, and use a stock stroke (3.250") crankshaft. This bore and stroke
combination calculates to 29.94 c.i. (Install a 1.8" offset
intake valve and a 1.5" offset exhaust valve, big steel cam, billet head,
and use a 44mm Mikuni carburetor with about an 8" long extension.)
The piston and rod combination to use for this particular bore and
stroke are as follows:
But to build a truly competitive 30 c.i. pulling engine,
use a 10hp/K241 Kohler block. (Acquire a 10hp block with K301
Due to the small bore and long stroke, this combination produces more torque (lugging power) at high rpms (wide open throttle) than building a 12hp block with a .050" overbore and stock stroke (3.250") crankshaft. If the engine is built correctly, and if the correct camshaft and gearing is used, it'll give the competition a kick in their butt! No joke. Use the same size valves, cylinder head and carburetor as the stock stroke engine above È. This bore and stroke combination is legal in the NQS's rules, as long as the cubic inch displacement does not exceed 30. With the 3.300" bore and 3.500" stroke, the cubic inches will be 29.94. But to be closer to 30 cubic inches, have a STD size crank journal ground .015" offset, resulting in a .030" undersize journal, lengthening the stroke to 3.5075". The results with the 3.300" bore and a 3.5075" stroke, the cubic inches will be 29.999, which is slightly under the legal limit. Doing this will gain an edge over the competition. Click here for an explanation of why a longer stroke works better. |
The NQS Outlaw 30 Cubic Inch Pulling Engine -
A "somewhat" competitive 30 cubic inch pulling engine is when a newer model
12hp Kohler block having a large intake port, the cylinder to be bored to
.050" oversize for a 3.425" aftermarket (J&E or Arias) piston/rings assembly,
and a stock stroke (3.250") crankshaft. This bore and stroke combination
calculates to 29.94 c.i. A 1.8" offset intake valve and a
1.5" offset exhaust valve, .533" steel cam, billet head, and use a 44mm Mikuni
carburetor with about an 8" long extension should be used.
But a truly competitive 30 c.i. pulling engine is when a
10hp/K241 Kohler block is used. For strength and durability, especially if
it's built to the max, it's best to use a 10hp block with K301
Because of the smaller bore and longer stroke, the combination
above È will produce more torque at
high rpm
(wide
open throttle) than the 12hp block with a .050" overbore and stock stroke
(3.250") crankshaft. Either engine can use the same size offset valves, camshaft,
carburetion and head. If the engine is built right, and if the tractor is
set up right, it'll give the competition a kick in their butt! No joke.
This smaller bore and longer stroke combination is legal in the NQS's rules, as long as the cubic inch displacement does not exceed 30. With the 3.300" bore and 3.500" stroke, the cubic inches will be at 29.94. But to be closer to 30 cubic inches, a STD size [steel stroker] crank journal can be reground .015" offset, resulting in a .030" undersize journal, lengthening the stroke to a maximum of 3.5075". The results with the 3.300" bore and a longer 3.5075" stroke, the cubic inches will be at 29.999, which is just under the legal limit. Doing this will gain slightly more of an edge over the competition. Click here for an explanation of why a longer stroke works better. |
How to Create a 38.3 or 40.8 CID Engine, or a Hybrid Kohler Engine Model K381 or K411 - An innovative concept by Brian Miller, because nobody else advertise this.
  This is considered "old school technology" by today's standards,
but it still works great, and if the engine is built right, it should be
very competitive for pulling. Plus, these type of engines are economical
to build. Anyway, a 38.3 CID hybrid engine requires that a STD size (3.875")
307 Chevrolet OEM-type cast piston, rings and wrist pin be used. And the
40.8 CID hybrid engine requires that a STD size (4") 327 Chevrolet OEM-type
cast piston, rings and wrist pin be used. To create either engine, besides
the piston/rings assemblies, the other parts needed are:
The K341/M16 engines have a STD bore of 3.750". With the 3-7/8" 307 piston, it'll have a 1/8" overbore. And with the 4" 327 piston, it'll have a 1/4" overbore. The 307 (1968-1973) and 327 (1962-1969) piston, rings and wrist pin are available at most auto parts supply stores. Coincidentally, the 307 and 327 Chevy engines have the same stroke as the Kohler K301/M12, K321/M14, K341/M16 and K361 engines, which is 3.250". The K341/M16 engines with a STD size 3-3/4" Kohler piston, stock 3.250" stroke crankshaft and stock head, they have a compression ratio of 7.4:1. But with a STD size 3-7/8" 307 piston, a stock stroke crankshaft and stock head, the compression ratio will be 7.7:1. And with a STD size 4" 327 piston, a stock stroke crankshaft and stock head, the compression ratio will be 8:1. If the 38.3 CID engine is built to the max at 4,000 rpm with reworked stock size valves, enlarged intake and exhaust runners, a quality performance torque cam and a bored-out 1.2" carburetor, it'll produce about 28hp and 37 ft. lb. of torque at 4,000 rpm. But if built to the max at wide open throttle with reworked stock size valves, enlarged intake and exhaust runners, a big performance cam and a bored-out 1.2" carburetor, it'll produce about 32hp at 5,500 rpm and 34 ft. lb. of torque at 5,000 rpm. And if built to the max at wide open throttle with a reworked (Chevy) 1.94" offset intake valve and (Chevy) 1.5" centered exhaust valve, enlarged intake and exhaust runners, a high-performance cam, and a bored-out 1.2" carburetor, it'll produce about 52hp at 7,500 rpm and 39 ft. lb. of torque at 6,000 rpm. If the 40.8 CID engine is built to the max at 4,000 rpm with reworked stock size valves, enlarged intake and exhaust runners, a quality performance torque cam and a bored-out 1.2" carburetor, it'll produce about 30hp and 39 ft. lb. of torque at 3,500 rpm. But if built to the max at wide open throttle with reworked stock size valves, enlarged intake and exhaust runners, a big performance cam and a bored-out 1.2" carburetor, it'll produce about 36hp at 6,500 rpm and 34 ft. lb. of torque at 5,000 rpm. And if built to the max at wide open throttle with a reworked (Chevy) 1.94" offset intake valve and (Chevy) 1.5" centered exhaust valve, enlarged intake and exhaust runners, a high-performance cam and a bored-out 1.2" carburetor, it'll produce about 56hp at 7,500 rpm and 43 ft. lb. of torque at 6,000 rpm. Here's how to make it happen:
|
Fill in the valve reliefs in
either piston with aluminum welding for higher compression, then grind or
machine the weld flat. Leave the notch untouched.
For either Chevy piston to come
flush with the top of the block at TDC, the big hole in the [Kohler] connecting
rod will need to be bored .046" offset toward the oil dipper for
installation of bearing inserts. (Installation of bearing inserts in the
[Kohler] connecting rod is highly advised for high rpm or at
Gain More Power and Torque by Moving the [16hp] Piston Closer to the Valves!
Only the OEM 16hp (K341) and 18hp OHV (K361) Kohler engine blocks, the center of the cylinder bore is offset .250" (1/4") with the centerline of the crankshaft main radial ball bearings. Because of the much larger bore, the piston is moved further away from the valves. On OEM pistons, the wrist pin is also located off-center .010" so they'll be less thrust (friction) on the cylinder wall, and this will allow the connecting rod to operate correctly. That's why these particular pistons have a notch in them indicating that the notch must face toward the flywheel.
In a high-performance 16hp engine, if the cylinder is bored in its original location (when the piston is installed off-center), and at high rpm, this will create a lot of friction in the area of the cylinder wall that's closest to the valves. To minimize or reduce this power-wasting friction, have the cylinder bored inline or centered with the center of the main radial ball bearings, or closest to the center of the main radial ball bearings as possible, depending on the diameter of the piston to be installed. More compression will be produced by doing this, too.
The best way to do this is acquire a [13 fin] 16hp block with an unworn, standard size cylinder. The reason it's best to use an unworn, standard size cylinder is for example, if a 3.825" (.075" oversized) diameter piston is going to be used, the cylinder will need to be bored .030" closer to the valves. The piston will then travel .030" closer with the main radial ball bearings. The piston still wouldn't be centered, but it'll be closer than the 1/4" offset. Larger diameter pistons may not be moved this close to the valves though. But it will help greatly in the performance characteristics.
All Kohler K-series and Magnum models K241/M10 (10hp), K301/M12 (12hp) and
K321/M14 (14hp) engine blocks have 13 cooling fins. Otherwise, there's really
nothing else special about these blocks. Except for certain K-series K241
(10hp) blocks that have K301 embossed
on the PTO end, which have a thicker cylinder wall. These blocks works best
for the 30 cubic inch class pulling tractors with a stroker engine.
The 12 and 13 fin 16hp Kohler blocks -
-
The 12 fin Kohler K-series and
Magnum engine block models K341/M16 (16hp) have an indentation in the cooling
fins (clearance for a straight oil fill/dipstick tube) and a threaded hole
towards the bottom of the cylinder. This block have a thinner cylinder wall
than the 13 fin block. This block is most common, and used mainly for light
duty lawn and garden equipment applications, and can be safely bored up to
a 3.825" [pulling] piston without danger of seriously weakening the integrity
of the cylinder wall.
- But the 13 fin Kohler engine block model K341 (16hp) have a thicker cylinder wall. This block is somewhat rare, and used mainly for heavy duty industrial applications and can be bored for a much bigger [pulling] piston, up to 4-1/8". Both blocks originally have a STD cylinder bore of 3.750".
Here's something to think about: Between the factory-stock 12hp and 14hp engines, there's 2.19 cubic inches of difference. This means you get 2 more horsepower for that much difference. But between the stock 14hp and 16hp engines, there's a whopping 4.63 cubic inches of difference, for just 2 more horsepower! The reason for this is because the friction that the piston place against the cylinder wall in the 16hp robs the engine of valuable power. Kohler had to add more cubic inches just to get a maximum of 16hp out of their K341 engine at 3,600 rpm.
And if you're wondering, the cylinder bore is centered in all the [Jones, Julian, etc.] aftermarket blocks.
Do not
attempt doing the above È on the 10hp,
12hp or 14hp engines! The cylinder on these engines are bored centered with
the centerline of the main radial ball bearings. Which should remain this
way even for a pulling engine.
Is it worth it moving the piston in a 16hp Kohler?
Engines that use a piston or pistons with a notch have an offset wrist pin.
The factory had to do this on a lot of big bore engine blocks because the
cylinder bore is offset with the crankshaft main radial ball bearing centerline.
To lessen wear on one side of the piston, the offset wrist pin allows the
piston to operate straight up and down in the cylinder and not at an angle.
If it can be done, then it's definitely worth moving the bore closer to the
centerline of the main radial ball bearings. The aftermarket Stock Altered
block has the bore in the stock location (.250" off of the centerline of
the crank, toward the starter side of the engine) and is not centered like
some must think. Most all the NQS S/A have the bores shifted closer to the
valves. By doing this you end up with a tighter combustion chamber for more
compression and power. We've done it for a long time on the stock Kohler
blocks by offset boring the engine toward the valves, then pressing in a
sleeve and offset boring the sleeve. You have to leave about .100 to .125
wall thickness on the sleeve on the valve side to maintain the strength.
Depending on how far you move it, the sleeve will show between the fins between
the valve box and jug. However, its cheaper just to buy the S/A block and
offset bore that, the unfinished bore of a S/A block is only about 3 1/2"
so you can offset it quite a bit and still get the bore to cleanup. I paid
around $1,000 to sleeve and offset bore an original Kohler block, but it
can be done. As far aftermarket blocks that have the bores center over the
crank is the Pro/Super Stock blocks like the J2 and others. |
Why a Longer-Than-Stock Stroke Works Better For Pulling Competition -
Many people (pullers) believe that an engine will produce more noticeable power and torque simply by boring the cylinder and installing a maximum of .030" oversize piston/rings assembly. But there's no need to do this, and it won't give the engine anymore noticeable power. The best thing to do is just bore the cylinder to the next oversize, if needed. Or if it's worn beyond .030", have it sleeved back to standard size.
What makes an engine produce more noticeable power and torque is not necessarily a larger diameter piston, it's having a longer stroke. For example: there's a world of difference in power and torque between a 10hp Kohler engine into a 12hp Kohler engine. Unlike a strong 10hp, a healthy 12hp engine will actually pull you back in the seat when you punch the gas. This is because not only the 12hp has an 1/8" larger bore than the 10hp, but it has a much longer crankshaft stroke, 3/8" longer, to be exact! 12hp engines are able to produce 2 more horsepower than the 10hp because of three things: 1) 1/8" larger bore, 2) 3/8" longer stroke, and 3) higher compression ratio because the 12hp use the same cylinder head with the same size combustion chamber as the 10hp. But there's not really that much of a noticeable difference in power and torque between a 12hp and a 14hp engine, because the 14hp has an 1/8" larger bore, but it has the same length stroke as the 12hp. 14hp engines are able to produce 2 more horsepower than the 12hp because of two things: 1) 1/8" larger bore, and 2) higher compression ratio because they use the same cylinder head with the same size combustion chamber as the 12hp. Another example is the 7hp and 8hp Kohler engines. These are virtually identical in every way except for the length of the stroke. The 7hp has a stroke of 2.500", and the 8hp's stroke is 2.750". A 1/4" longer stroke (and higher compression due to the same cylinder head) results in 1hp more. Many new automotive engines nowadays have a small bore and long stroke. Simply because it works better!
A longer-than-stock stroke works better for more engine torque because at very high rpm (wide open throttle), it takes less time for the flame front (combustion) to travel down in the cylinder than it would to travel across the top of the piston. Therefore, due to the longer stroke, the fuel burns more thoroughly and the engine produces more power from the expanding gases of the burning fuel. For pulling competition, on a short stroke engine, at very high rpm and when the engine is under a load, some of the fuel will go unburned [out the exhaust] and loss of power will result. A short stroke engine works best for racing, but not for pulling. Racing engines and pulling engines are not built on the same principles. Racing engines require horsepower (speed) and pulling engines require torque (lugging power). This is why some "cheaters" in pulling run an illegal stroker engine in a class when they're not supposed to. As a result, on a biting track, when all the legal engines have run out of power, the stroker engine will keep lugging on out the gate. This is true for all engines, despite if it's a gas/alcohol burner, Diesel, 2- or 4-cycle. Return to previous paragraph È
If your club's rules allows a longer-than-stock stroke in any particular class, lengthen or increase the crankshaft's stroke slightly by grinding the crank journal .030" undersize with a .015" offset. Doing this will increase the stroke by .015". This would have to be done on an standard size, unworn journal. If the journal is worn, the amount of wear will have to be subtracted from the increase in stroke. Grinding the journal offset to increase the stroke is a way to slightly increase engine performance. It won't make a world of difference in engine performance, but it does help. Many professional high-performance engine builders do this to gain three things:
- Increase the cubic inches to the max according to the rules for more power and torque.
- Pop the piston out of the cylinder to increase the compression ratio.
- The smaller diameter journal will reduce friction at very high rpm. It'll allow an engine to turn freer, which will help to produce more power and torque.
Here's another thing to consider: half of the .015" increase in stroke is .0075". So .0075" plus the .020" offset rod adds up to .0275". Therefore, the piston will pop out of the cylinder at .0275". If the head was milled at .050", the clearance between the piston and head would be .0225". (.0275" - .050" = .0225".) This would still be a safe margin of clearance. The slightly longer stroke would help to increase the power and torque, PLUS the increase of the compression ratio with the .050" milling of the head (remove the raised ridge that mates with the head gasket) would help in power and torque, too.
Also, a 10hp block can be bored to use a 12hp piston and a 12 hp block be bored to use a 14hp piston, but this makes the cylinder wall very thin (approximately 1/8" thick). And it's safe to bore a K301 10hp block for use with a 12hp piston. If an ordinary block is not going to be used for pulling, it should be OK. But if it is going to be used for pulling, It is recommended that the cylinder be "strapped" to the crankcase to prevent the possibility of cylinder/crankcase separation, which can be a terrible experience. Also, to maintain precision engine balance, a 14hp crankshaft must be used with the 14hp piston.
If methanol is going to be burned in an engine, and because the engine will have a thinner cylinder wall with increased compression, It is highly recommended that the cylinder be fastened to the crankcase, to prevent the possibility of cylinder/crankcase separation (engine explosion).
When burning methanol fuel, with a thin cylinder wall, and if the cylinder isn't securely strapped to the crankcase, the engine will likely explode at wide open throttle while under a load on a cool night. The reason this will happen on a cool night is, because air is more dense when it's cool, making it "thicker". The colder air is, the "thicker" it becomes. (This is why it's easier to breathe on a cool day than on a hot day, or when in an air conditioned place.) Anyway, in a cool, dense-air environment, an engine, when run at wide open throttle, especially with a big cam, big ports and bigger valves, will build up more compression, placing a tremendous strain on the thin cylinder wall every time combustion occurs.
Moreover, if you had a 10hp block bored for a 12hp piston, or a 12hp block bored for a 14hp piston, and you use your tractor to push snow, definitely fasten the cylinder to the crankcase! Because it now has a much thinner cylinder wall, and the cold winter air is more dense (like the air is thicker or there's more of it). Dense air will build up the compression pressure within the combustion chamber, causing the engine to produce more power. But what also happens is at full throttle, this high compression is pushing upward on the cylinder head, and pulling upward on the cylinder wall. And sometimes the cylinder wall will break, ruining the whole engine. I know, we've had this happen before. No joke.
Actually, it's in the foreseeable knowledge of the laws of physics on how a successful pulling engine (and entire tractor) is built. Plus, it's the combination of tractor and driver working together as one that does well at the pulls.
If a bigger flathead engine still won't give you enough power, then use an overhead valve engine. They'll produce more horsepower and torque per cubic inch than any flathead engine ever will.
Personally,
I don't fasten All Thread rods directly into the block or bearing plate to
strap the cylinder. I've seen where some engine builders do that. I found
that it's much easier just to use two light-weight 1/8" x 1" flat pieces
of welded-together upside-down "T" shaped steel brackets. I fasten one bracket
using the two upper bolts against the bearing plate so the bracket will clear
the raised ridges on the plate, and the other bracket is installed on the
PTO end of the block, and then I weld the threaded rods to them. This setup
is easier to remove and reinstall when it comes time to freshen the engine.
I think it works great and looks good, too.
And it's doubtful if a 14hp block can be bored for use with a 16hp piston. Some people have done this with success. But the center of the outer part of the cylinder may need to be offset one way or the other (not like in the 16hp block) to center the bore in the block as not to break through the cylinder wall during the boring process. If attempting this, it'll be a good idea to install a head strap rather it's for competition pulling or general yard use.
Boring a 14hp engine to accept a STD size 16hp piston is a tricky process. First, you must find the "center" of the cylinder. This is done by measuring the outside of the cylinder to find the thinnest and thickest parts. If this isn't done, then the boring process could break through the thin part of the cylinder wall. And if the cylinder is bored offset, the wrist pin in the piston will allow the piston to be centered with the crank journal.
"Strapping" the cylinder to the crankcase is when a flat piece of heavy steel or aluminum is across the cylinder head and fastened by means of two minimum 1/2" diameter threaded rods, one located just behind the flywheel and the other on the PTO end of the block. It keeps the cylinder from literately breaking loose from the crankcase because of a thin cylinder wall and/or due to extremely high compression. Position the strap directly over (center of) the cylinder and not over the valve area.
And if there's no bolt holes on the PTO side of the block, then the block can be safely drilled and tapped on the PTO side for a head strap. Just be sure to drill the holes where there's most metal so you won't get into the crankcase. Torque the studs to 10 ft. lb. each.
The Correct and Professional Way to Sleeve a Cylinder:
FYI: The term "resleeving" is removing a previously installed worn sleeve and installing a new one. And "sleeving" is installing a new sleeve when one wasn't already installed.
A sleeve should be installed in a block if the cylinder wall...
- Is severely gouged or scored and will not "clean up" at .030" (above ring travel).
- Is bored to maximum of .030" and is worn or scored, but no bigger piston and rings are available.
- Is cracked towards bottom. (Block is useless if crack is at top of cylinder.)
- Has a wide chunk broke out on the bottom (due to connecting rod failure) and may not provide stability of the piston.
If a block has a small missing
chunk at the bottom, and if the chunk isn't wide enough for the piston to
be unstable in the cylinder, then don't worry about sleeving the block. If
the cylinder wall don't need to be bored (honed) to the next oversize, just
use it as it is. As a matter of fact, pulling engines with a billet rod requires
that the lower end of the cylinder be ground away on each side for clearance
of the wider rod. If performed correctly, this will not interfere with the
stability of the piston whatsoever. But if it's a pretty wide missing chunk,
and you have doubts about the stability of the piston, then perhaps the block
needs to be sleeved. Before installing the sleeve, the cylinder is made bigger
with a boring bar. If performed correctly, the boring bar is adjusted so
it won't cut away approximately 1/8" bottom portion of the cylinder. The
missing chunk will not interfere with the boring process either. The boring
bar machine is positioned firmly with the cylinder to prevent any slippage.
As it bores the cylinder, it'll skip over the missing chunk and continue
to bore the rest of the cylinder. Then after the sleeve is installed, it's
honed for fitting of the piston and rings.
How to Install a Cylinder Sleeve:
- Acquire a cast iron sleeve that's slightly larger in diameter than the cylinder if a .030" oversized piston were installed. Make sure it's slightly longer than the overall length of the cylinder, too. (Virtually any place that sells internal engine parts (pistons, rings, bearings, etc.) offers cylinder sleeves, too.)
-
Bore the cylinder exactly .003" smaller than the outside diameter
of the sleeve.
Despite
the diameter of the cylinder, the .003" interference fit makes for a perfect
press fit. Do not make it any tighter or the cylinder could split or
crack!
- When boring the cylinder, leave approximately an 1/8" ledge or "step" at the bottom of the cylinder for the sleeve to butt against and not [possibly] work it's way down into the crankcase as the engine reaches its normal operating temperature.
- Chamfer or bevel the outside lower end of the sleeve for easier installation in the cylinder.
- Apply high strength sleeve retainer around the sleeve or in the cylinder, and using an upright hydraulic press, carefully and slowly press the sleeve perpendicular into the cylinder until it bottoms out against the ledge. To ease installation of the sleeve into the cylinder, heat the engine block in an oven and cool the sleeve in a freezer. It should then just slip in without using a press. But this must be done quickly before the block cools and sleeve warms up.
- Once the sleeve is installed, grind or machine the protruding upper portion of the sleeve so it's even with the top of the engine block.
- Bore or hone the sleeve for a standard size piston and rings assembly, then chamfer the upper edge of the sleeve so the rings will slide in easy upon installation.
- That's it! Any professional machine shop that performs quality machine work on automotive engines should be able to install a sleeve in a Kohler or virtually any other engine block.
Advertisement:
| If you need to purchase a cylinder sleeve or the cylinder(s) sleeved in your engine block, contact Elson Nichols of Loop 70 Auto Parts and Machine, 14 Business Loop 70 East, Columbia, Missouri 65201. Phone: 1-573-449-0893. E-mail: vjnen@centurytel.net. He has many years of experience in engine machine work and he can professionally sleeve your block and then bore it for a STD size piston/rings assembly. |
Maintain Proper Crankcase Vacuum So the Single Cylinder Engine Will Produce More Power!
The
job of the reed valve in the crankcase breather assembly is to prevent outside
air (plus dust and dirt) from being drawn inside the crankcase. It also maintains
crankcase vacuum so the engine will produce more power, and it prevents motor
oil from being blown out (as long as the piston rings are in good condition).
When reinstalling the reed valve/breather plate assembly on models K141,
K160/K161, K181/M8, the reed valve faces outward. And on all Kohler engine
models, the small hole faces downward, so any oil in the breather assembly
will drain back down into the crankcase. And be careful not to block the
oil drain hole when using
Clear RTV Silicone Adhesive Sealant upon reinstalling.
By the way - I've always preferred to use
Clear RTV Silicone Adhesive Sealant for two reasons: being
it's an adhesive, it bonds parts together, forming a leak-proof seal; and
being it's clear, it makes for a clean-looking repair job. It can't be seen
between the parts.
The job of the [coarse] filter in the crankcase breather assembly is to trap oil vapors from exiting the crankcase (as long as the piston rings are in good condition), and it traps outside dust and dirt from entering the crankcase. It should be used only on engines where the crankcase is not filtered through the air filter assembly with a rubber tube (Quiet Line and Magnum models).
If clean motor oil has contaminated (clogged) a new or good pleated air filter, there's no need to discard the filter and purchase a new one. The oil can be dried out of the filter by soaking it in paint thinner (the thinner will mix equally with the oil), and then allow it to air-dry at room temperature overnight. As the paint thinner dries, the oil will dry out, too.
When reinstalling the crankcase breather assembly on a single cylinder engine, make sure all the original components are reinstalled in the same order they were removed so that proper crankcase vacuum is maintained. This is important on any engine, especially a pulling engine. More horsepower will be created and the inside of the crankcase will stay cleaner longer.
Dyno tests have proven that a single cylinder engine will produce more power with the reed valve and breather plate installed. Some pullers like to use just a fabricated aluminum cover (an "aluminum valve cover" just for looks) and not the reed valve and breather plate. This is wrong because without the reed valve in the crankcase breather, with the engine running and as the piston(s) moves upward, (in a single- or two-cylinder engine) air (and dust particles in the atmosphere) will be drawn into the crankcase through the breather cover hole. And as the piston goes back down, air will be forced out of the crankcase through the same hole. This rapid "in and out" movement of air will rob an engine of power because air must be compressed through the small breather hole. Hot air (and the hot oil vapors) are supposed to be forced out of an engine, not sucked in. And the piston will automatically vent the pressure on the downward stroke through the breather hole.
On the cast iron block 7hp and 8hp Kohler engines, the reed plate is installed with the reed valve facing outward or towards you. This allows air to escape out the crankcase, but no air can enter into the crankcase.
How the Reed Valve Works:
The underneath or backside of the piston creates a vacuum within the crankcase and valve spring compartment. When the piston goes down, air that's in the crankcase is forced out through the reed valve and cover hole, and when the piston goes back up, air wants to be drawn back in, but the reed valve prevents this from happening. Therefore, a vacuum is created and maintained within the crankcase. Air can only be forced out of the crankcase and not be allowed in. By the way - an automotive PCV (Positive Crankcase Ventilation) valve can be substituted for the reed valve. But most pulling tractors don't really need a PCV valve to maintain crankcase vacuum. Nothing will be gained by installing one. It'll just be for looks only. Besides, the reed valve design works excellent just the way the factory intended.
If there's a steady puff of smoke coming out of the crankcase breather, the reason for this is because the piston rings are worn. What is happening is a small part of the exhaust gases in the combustion chamber is bypassing the gaps in the rings, goes down in the crankcase and then out the breather. So it may time for a complete engine rebuild soon. If an engine rebuild is out of the question any time soon, what could be done to prolong the engine life a little longer is switch to 10W40 full synthetic motor oil for warm weather use.
Advertisement:
| If you need any of the parts listed below
Ê, please contact A-1 Miller's Performance
Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
1-573-449-7347. E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
|
 Crankcase Breather
Filter. Replace deteriorated filter and prevent dust and dirt from entering
crankcase. Also traps oil vapors from exiting crankcase. Use on engines where
the crankcase is not filtered through the air filter assembly with a rubber
tube. Fits Kohler K-series and Magnum engine models K141, K160/K161, K181/M8,
and twin cylinder engine models KT17, KT17II, KT19, KT19II, M18 and M20.
|
|
 Small Crankcase
Breather Filter. Replace deteriorated filter and prevent dust and dirt from
entering crankcase. Also traps oil vapors from exiting crankcase. Fills about
1/3 area of breather plate. Use on engines where the crankcase is not filtered
through the air filter assembly with a rubber tube. Fits older Kohler K-series
engine models K241 (10hp), K301 (12hp), K321 (14hp), K330/K331 (12½hp),
K341 (16hp), K361 (18hp OHV), and various Magnum models M12 (12hp), M14 (14hp)
and M16 (16hp).
|
|
 Large Crankcase
Breather Filter. Replace deteriorated filter and prevent dust and dirt from
entering crankcase. Also traps oil vapors from exiting crankcase. Fills entire
area of breather plate. Use on engines where the crankcase is not filtered
through the air filter assembly with a rubber tube. Fits various newer Kohler
K-series 10-16hp and various Magnum engine models M10 (10hp), M12 (12hp),
M14 (14hp) and M16 (16hp).
|
|
| Crankcase Breather Reed Valves. Replace damaged reed valve
to prevent outside dust and dirt from entering crankcase and to maintain
crankcase vacuum so engine will produce more power.
|
|
| Crankcase Breather
Neoprene
Rubber Seals. Places pressure against reed valves above
È to insure better crankcase vacuum.
|
Reed Valve for Kohler K-series
and Magnum engine models K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp),
K341/M16 (16hp) and K361 (18hp OHV).
Reed Valve and Plate Assembly
for Kohler K-series and Magnum engine models K141 (6¼hp), K160 (6.6hp),
K161 (7hp) and K181/M8 (8hp).
Fits certain Kohler engine models:
CH18, CH20, CH22, CH23, CH25, CH620, CH640, CH730, CH740, CV15, CV25, K141,
K160/K161, K181/M8, MV18 and MV20.
Fits certain Kohler engine models:
CH20, CV18, CV20, CV22, CV25, CV624, CV670, CV675, CV680, CV724, CV725, CV730,
CV740, K241, K301/M12, K321/M14, K341/M16, MV16, M18, MV18, M20 and MV20.
Use an Auxiliary Crankcase Breather for Better Engine Venting Above 4,000 rpm...
The factory OEM crankcase breather alone isn't adequate for all high-performance single cylinder engines, especially big cubic inch engines running at all-out rpm. They build up more pressure in the crankcase due to the longer stroke and bigger piston. The downward movement of the piston will force air out of the crankcase. At very high rpm (well above 4,000 rpm), the small holes in the engine block and breather assembly sometimes aren't large enough for a sufficient amount of air to pass through or exit the crankcase. When air exits the crankcase through the OEM breather at very high rpm, it will sometimes take some crankcase oil with it, spewing an oily mess on the track, and probably on the tractor. So if your engine has this problem (not all engines spew oil at high rpm), and to keep this from happening, your engine needs an auxiliary crankcase breather. It helps to relieve some of the air pressure inside the crankcase that's placed on the stock breather assembly. But by looking at the picture to the right, you'll notice that this is an open breather system with no one-way check valve to prevent air from re-entering the crankcase. Relax. This is how it works: the faster a single cylinder engine revs, the less time air has to exit and re-enter the crankcase. In other words, at very high rpm, and being air can be compressed as well as it can be expanded, it cannot re-enter the crankcase through the auxiliary breather simply because there isn't enough time for it to do so. Therefore, the crankcase maintains zero vacuum. The auxiliary breather also has a filter in it. This is to prevent dust and dirt from entering the crankcase at low rpms. And the auxiliary crankcase breather doesn't help to make more horsepower. It just keeps oil inside the engine and off the track.
Advertisement: (posted 1/27/11)
 If your engine needs
an auxiliary crankcase breather kit, please contact A-1 Miller's Performance
Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
1-573-449-7347. E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
For better engine venting and less oily mess above 4,000 rpm. Kit includes
street elbow, short pipe fitting, 12" vinyl tubing, clamp and MOPAR breather.
|
NOTE: For Kohler blocks, use
a 3/4" NPT taper pipe tap to cut threads in the block to install the pipe
fitting. For aftermarket blocks, use a 1" NPT taper pipe tap to cut threads
in the block to install the pipe fitting. Sold below
Ê.
Checking for a Worn Piston -
If there's any oil on top of the piston, this means the
piston is badly worn, which caused the rings to wear. New top and second
piston rings have a square edge (actually, the second ring has a slightly
"angled" edge), and they operate in a particular manner. The top ring holds
the compression. The second ring is the oil scraper or oil control ring.
The "angled edge" allows it to flex as it travels up and down in the cylinder.
It slides over the oil on its way up in the cylinder and scrapes the oil
on it's way down. As the skirt of the piston wears, the piston wobbles side
to side in the cylinder (called piston slap), causing the square edge on
the rings to become rounded. When this happens, the second ring can't slide
over the oil or scrape it back down as well. Instead, it pushes some of the
oil past the gap in the top ring and place it on top of the piston, and it
gets burned along with the gas. The oil ring assembly is the lubricator.
It lubricates the cylinder wall and other rings so they'll last longer. The
rings in all 4-cycle engines, rather it be a gas or diesel engine, small
engine or automotive, operate the same way.
Speaking of a worn piston, if your engine makes an uneven "clattering" sound when running or especially when under a load, then perhaps the piston is loose or worn in the cylinder bore. To check this, remove the cylinder head, and with the piston positioned at TDC, forcibly and quickly move the piston side to side by hand (side thrust of the crankshaft). If you hear a "slap, slap" sound, then the piston is badly worn.
Also, carbon deposits in a
combustion chamber can "eat away" the edge of the piston that's next to the
valves. Carbon is harder than any metal. The only thing that's harder than
carbon is diamond. Carbon deposits is what is left behind with burning of
a fossil fuel. This is why it's so important to have a fine-tuned engine,
so it'll leave behind very little carbon as much as possible.
According to Kohler's specs, when using an OEM or aftermarket piston in an engine, the piston-to-cylinder wall clearance should be no less than .007" and no more than .010". But make it tighter for pulling (.007"). Because OEM pistons will wear slightly when used in a high rpm application. As for a forged, high-performance piston (Arias and J&E), when hot, they will swell more than an OEM piston. Therefore, requiring slightly more clearance. Most high-performance pistons require a .010"-.014" clearance. But check with the manufacturer of the piston for the exact clearance.
If you had the cylinder in your engine block bored oversize, before installing the piston/rod assembly in the cylinder, always clean the cylinder wall with warm soapy water and use a clean cloth that's white in color to see and to remove the microscopic metal dust that get lodged in the cross-hatch honing process of the cylinder wall. (Machine shops do not do this.) The metal will, more than likely, cause the rings to wear prematurely if this is not done. After cleaning, allow the cylinder to air-dry.
The Correct Way to Install Piston Rings -
Lubricate the wrist pin with clean motor oil, and then install the connecting rod on the piston. NOTE: If the piston has a notch on the top (16hp and 18hp OHV engines), install the rod to the piston with the oil hole in the cap facing toward the camshaft. Make sure the match marks are aligned on the rod and cap!
Next, install the rings on the
piston in their correct order according to the provided instructions or refer
to the drawing to the right for correct piston ring installation.
è
Installation of rings on the piston are as follows:
- The oil lubricating (bottom) ring(s) goes on first.
- The oil scraper (middle) ring goes on second.
- Then the compression (top) ring goes on last.
Never attempt to install piston rings in reverse order or they might break upon installation! Install the rings in the order as follows: (The below Ê applies to all 4-stroke small air- or water-cooled engines, automotive, tractor, heavy equipment engines, etc.)
- The bottom ring(s) usually have no particular (upward or downward) way of installing, as they don't flex either way. If it's a three-piece ring, the expander installs first and butts end to end. The ends do not over-lap. The expander "expands" the two thin oil lubricator rings so they can apply more pressure against the cylinder wall to work better.
-
Make sure the middle or second ring is installed correctly! This step is
very important! This particular ring actually flexes. It has a slight angle
on the outer edge that "scrapes" the oil from the cylinder wall on its way
down and glides over the oil on its way up. If this ring isn't installed
correctly or right-side-up, the engine will smoke a lot and use lots of oil.
For most middle rings, the
bevel
(inside angle) faces downward. But for a chrome-edge second ring, the bevel
faces upward. However, if there's a dot (punch mark) or the word TOP or PIP
laser-etched on the ring, it faces upward. And if the middle ring came with
an expander (rippled spring-like ring), install it under the ring. It helps
to stabilize the piston in the cylinder.
- NOTE: If the middle ring is installed wrong side up, and if the engine smokes a lot, this ring can be removed and reinstalled right side up. It can be reused because very little wear has occurred to it. There is no need to purchase another new set of rings due to improper installation. Because installing new rings incorrectly doesn't necessarily cause them to wear more, they just cause the engine to smoke out the exhaust.
-
If there's no specific
instructions on how to install the middle ring, and if a powerful magnifying
glass isn't available to see the angle on the outer edge, then lightly rub
the outer edge of the ring side to side against a flat piece of ceramic tile
at an exact 90° angle. You should see a shiny area on one side of the
angle. Mark the ring so the shiny area will face downward when installing
the ring on the piston.
- And as for the top ring, if it has square edges with no bevel, then there's no certain way how it installs on the piston, being it just holds the compression. And just like the second ring, if there's a dot (punch mark) or the word TOP laser-etched on the ring, it faces upward.
Instructions on how to install the rings should be in the box they came in. And if you're wondering if there's any certain "tricks" when installing chrome rings on the piston or breaking them in, well, there really isn't any. Just install them as you would with ordinary cast iron rings. Being chrome rings are made of much harder material, it just takes longer for them to seat, they hold up to heat better, and they last a lot longer. Go here for more information: http://www.totalseal.com/howdoo.html.
If there's only one ring with a shiny edge, it's the top ring. It has a chrome edge to last longer. If it has a bevel on the inside, it goes upward. But if there's no bevel, it can be installed either way. If the 2nd ring has a chrome edge also, and if it has a bevel, it faces upward. But if it doesn't have a chrome edge, the bevel faces downward. If it has a step on the outer edge, it faces downward. And stamping (the word TOP or .010, .020 or .030) or a paint spot on the ring(s) ALWAYS face upward.
The Differences Between "Deglazing", "Honing" and "Boring" a Cylinder:
-
"Deglazing" is roughing up the
cylinder wall surface with a rotary
cylinder deglazer. A cylinder deglazer can be of the
non-adjustable/spring-loaded ball-type, commonly known as the
Flex Hone (but also called a
dingleberry hone), or the adjustable type (to place more
or less pressure against the cylinder wall) with three spring-loaded, long,
narrow stones, commonly known as the
Rigid Cylinder Hone. The ball-type will get into places
[on the cylinder wall] where the three-stone deglazer can't. And of course,
the piston rings will only make contact with the high places on the cylinder
wall. Anyway, the deglazing process removes the "glaze" or shiny, slick surface
that's on a used cylinder wall, and when moved up and down quickly, the deglazing
process creates ±60º cross-hatch pattern
or tiny grooves, which acts as a reservoir so the rings can be better lubricated
and break-in easier for longer life. Depending on how much metal is removed
or ground away, deglazing may enlarge the cylinder diameter as much as .003".
- "Boring" is necessary when removing an excess of metal from a cylinder for an extremely large/oversize piston and rings assembly.
- "Honing" is slight boring or grinding of a cylinder with an adjustable rotary honing stone to make the cylinder oversize for a .010" or possibly a .020" oversize piston and rings. Honing is the final step after the boring process to slightly enlarge the cylinder further a few thousandths of an inch so it'll be within specs of the oversize piston and rings assembly. Just like deglazing, honing also creates cross-hatch lines or microscopic grooves, which retains oil and allows the rings to be better lubricated and break-in easier.
- Also, honing a cylinder and honing a connecting rod are a very similar process because it only removes a few thousandths of an inch of each. Plus, it makes the big hole in the rod a perfect circle. Boring a connecting rod is when a lot of metal is removed. And connecting rods are never deglazed.
Deglazing the Cylinder -
Despite how nice and smooth the cylinder wall may be, it'll always a good
idea to "break the glaze" with a drill-operated, spring-loaded cylinder deglazer.
Apply a lightweight lubricant such as
Liquid Wrench or
WD-40, and when deglazing the cylinder, and on the last
few strokes, give it a quick up and down motion to produce a 60° cross
hatch pattern. This only takes a few seconds to complete. The grooves in
the crosshatch marks retains oil so the rings can break-in quicker and last
longer. After the deglazing process, thoroughly clean the cylinder wall with
cleaning solvent, then finish cleaning with warm soap and water to remove
the tiny metal fragments left behind during the deglazing or honing process.
If these are not removed, severe wear of the rings could result. Then use
a clean cloth (white in color) around the cylinder wall to see that the wall
is free of the metal fragments. Remember - metal flake looks in paint, not
in crankcase oil. 
About Piston Ring Gaps -
As an engine heats up while running, due to normal combustion heat and cylinder
wall friction, the piston rings expand, decreasing the gap in the rings to
seal in the compression and better control oil usage. This is normal for
all piston-powered engines. The smaller gap specs shown in Kohler's (or any)
engine repair manual are for low rpm engines (up to 4,000 rpms) and the wider
gap specs are for high-performance engines
(wide
open throttle) because they operate at a much higher temperature. Not
all piston rings are machined perfect. Fit each ring squarely in the cylinder
with the piston and use a
feeler gauge to accurately measure the gap.
Grind or file the ends of each ring until the gap is within
specs. Failure to do this could cause the ends of the ring(s) will make contact,
and the excessive expansion will cause the cylinder wall to become scuffed
or scored.
Being piston rings rotate in
the cylinder as the engine heats up and cools down, there is really no need
to stagger the ring gaps 120° or 180° on the piston upon installation
in the cylinder. Actually, it doesn't matter if the ring gaps are offset
with each other or not because heat expansion rotates the rings in the cylinders
a few thousandths of an inch each time the engine is ran. Personally, whenever
I rebuild an engine, I always prefer to stagger the ring gaps 180° just
because it makes me feel good knowing they're offset. But then a few years
later when I freshen the same engine (install new rings, etc.), I notice
that the ring gaps are almost aligned with each other. It's weird how this
happens, heat expansion does it. But if it'll make you feel better, go ahead
and stagger the gaps anyway.
Use a generous amount of clean SAE 30 weight heavy duty conventional (petroleum-based) motor oil to lubricate and coat the cylinder wall, piston and rings (be sure to coat all other moving parts inside the engine with the same oil). Synthetic motor oil shouldn't be used on the piston rings or as a break-in oil because it'll take much longer for the rings and other moving parts to produce a hardened wear surface, especially for the lifters and cam lobes. And never use a lightweight spray lubricant such as Liquid Wrench or WD-40 on internal parts to assemble a fresh engine! Spray lubricants are too thin and will cause premature wear to the bearings, camshaft lobes, piston, rings and possibly the cylinder wall! Liquid Wrench and WD-40 works great for a lot of things, but not for assembly of a rebuilt engine. And on a cast iron block Kohler engine, ALWAYS apply oil inside the camshaft and on the cam pin to prevent engine seizure upon startup! If a freshly rebuilt engine is going to be in storage for a long period of time, quality automotive lubricating grease should be used instead of oil for the camshaft and pin, and on the rod/crank journal. The reason grease works better for storage is because most of the oil will eventually drain off the parts, allowing somewhat of a "dry startup", which could damage or cause excessive wear of valuable parts.
When
installing the piston and rings in the cylinder, the 10hp, 12hp and 14hp
Kohler pistons installs either way because the wrist pin is centered in the
piston. But if the [OEM] piston has a notch, such as the 16hp flathead and
18hp OHV single cylinder cast iron block engine pistons, these install with
the notch facing toward the flywheel end of the block. And to lessen
the chance of blow-by, don't forget to stagger the ring end gaps 180º.
Then use a quality-made
piston ring compressor tool or if a ring compressor isn't
available, a ring compressor can be fabricated out of clean (no paint, rust,
etc.) 2" x 14" x 16 gauge steel sheet metal (heating duct tin works excellent)
with a large adjustable radiator hose clamp to compress the rings. And be
sure that everything is absolutely clean before installing the piston
assembly in the cylinder!
Use a heavy wooden dowell or the wooden or rubber end of the handle of a medium-sized hammer to gently drive the piston into the cylinder. Be sure that the connecting rod is aligned with the crank journal as the piston is driven into the cylinder! If the piston stops going into the cylinder for any reason, stop to see what is stopping it. Don't just keep pounding it!
Piston ring technology has progressed a lot in recent years. Many ordinary small engines and automotive engines nowadays have thinner rings, and the rings place less tension against the cylinder wall. This is mainly to improve fuel economy and reduce exhaust emissions. It also helps the engine produce more power. Also, the engine idles smoother and revs up quicker.
Chrome VS Cast Iron Rings -
Some ring sets comes with the top ring having a chrome outer edge. Personally, I never experienced any differences between using a chrome ring or a cast iron ring. It seems that as long as the oil is changed regularly, a clean air filter is installed and the engine runs cool, one ring lasts just as long as the other. Because incoming dirt in the air intake system and in the oil, and overheating of the combustion chamber are the biggest killer of quality piston rings.
Wrist Pin Retaining Snap
Rings -
For high-performance use (especially wide open throttle operation), use [the proper size] internal snap rings instead of the OEM retaining clips to retain the wrist pin in the piston. Because OEM retaining clips can wear excessively and on rare occasions, they've have been known to come loose at high rpm.
Advertisement:
| If you need a new ring set or a new piston/rings assembly, please
contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia,
MO 65203-9136 USA | Phone:
1-573-875-4033. Please call Monday-Friday (except Holidays), 9am to 5pm,
Central time zone. If no answer, please try again later. (When speaking
with Brian, please be patient because I stutter.)
Fax: 1-573-449-7347.
E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
| NOTE: All parts listed here are NEW, unless otherwise stated. I do not sell cheap junk! As a matter of fact, most OEM Kohler parts are made in China now. Kohler owns some of the factories in China that make the parts. And most aftermarket parts are also made by Kohler in China. Kohler just place the part(s) in a generic box and sell them for less money. So when purchasing a genuine OEM Kohler part that comes in a box with the Kohler name on it, you're really just paying more money for the name. And as far as some parts being no longer available - either the parts didn't sell well or the EPA is trying to phase out parts for the old cast iron block flathead engines because they produce more air pollution than the newer OHV engines. |
 Ring sets for Kohler models
K90 (3.6hp), K91 (4hp) cast iron block flathead engine with a STD size cylinder
bore of 2.375" (2-3/8"). Made of high grade cast iron for durability.
|
Ring sets for Kohler and
Magnum models K141 (6¼hp), K160 (6.6hp), K161 (7hp) and K181/M8 (8hp)
cast iron block flathead engines with a STD size cylinder bore of 2.9375"
(2-15/16"). Made of high grade cast iron for durability. NOTE:
The cylinder in model K141 will need to be bored to 2.9375" because the
piston/rings for the 2-7/8" bore are no longer available.
Piston, ring set, wrist pin and retaining clips for Kohler and Magnum models K141 (6¼hp), K160 (6.6hp), K161 (7hp) and K181/M8 (8hp) cast iron block flathead engines with a STD size cylinder bore of 2.9375" (3-15/16"). Ring sets made of high grade cast iron for durability. NOTE: The cylinder in model K141 will need to be bored to 2.9375" because the piston/rings for the 2-7/8" bore are no longer available. FYI: The biggest piston and rings set available for any Kohler engine is .030". If a .030" cylinder wall is in bad condition, then the cylinder will need to be sleeved back for a STD size piston and rings, or acquire another block (matching yours) with a cylinder wall in good condition.
|
Ring sets for Kohler K-series
and Magnum models K241/M10 (10hp) and K482 (18hp) cast iron block flathead
engines with a STD size cylinder bore of 3.250" (3-1/4"). Ring sets made
of high grade cast iron for durability. Note
- These ring sets will not fit high-performance aftermarket pistons (Arias,
JE, etc.). Check your piston carefully before ordering.
|
Ring sets for Kohler K-series
and Magnum models K301/M12 (12hp) and K532 (20hp) cast iron block flathead
engines with a STD size cylinder bore of 3.375" (3-3/8"). Made of high grade
cast iron for durability. Note - These ring
sets will not fit high-performance aftermarket pistons (Arias, JE, etc.).
Check your piston carefully before ordering.
Piston, ring set, wrist pin and retaining clips for Kohler K-series and Magnum models K301/M12 (12hp) cast iron block flathead engines with a STD size cylinder bore of 3.375" (3-3/8"). Compression height is 1.7". And being the wrist pin is centered, these pistons can be installed in either direction. Ring sets made of high grade cast iron for durability. To maintain engine balance in a twin cylinder engine, two sets of matching oversize pistons and rings are required. FYI: The biggest piston and rings set available for any Kohler engine is .030". If a .030" cylinder wall is in bad condition, then the cylinder will need to be sleeved back for a STD size piston and rings, or acquire another block (matching yours) with a cylinder wall in good condition.
|
Ring sets for Kohler K-series
and Magnum models K321/M14 (14hp) and K582 (23hp) cast iron block flathead
engines with a STD size cylinder bore of 3.500" (3-1/2"). Made of high grade
cast iron for durability. Note - These ring
sets will not fit high-performance aftermarket pistons (Arias, JE, etc.).
Check your piston carefully before ordering.
Piston, ring set, wrist pin and retaining clips for Kohler K-series and Magnum models K321/M14 (14hp) and K582 (23hp) cast iron block flathead engines with a STD size cylinder bore of 3.500" (3-1/2"). Compression height is 1.7". And being the wrist pin is centered, these pistons can be installed in either direction. Ring sets made of high grade cast iron for durability. FYI: The biggest piston and rings set available for any Kohler engine is .030". If a .030" cylinder wall is in bad condition, then the cylinder will need to be sleeved back for a STD size piston and rings, or acquire another block (matching yours) with a cylinder wall in good condition.
|
Ring sets for Kohler K-series
and Magnum models K341/M16 (16hp; flathead) and K361 (18hp single cylinder
OHV) cast iron block engines with a STD size cylinder bore of 3.750" (3-3/4").
Ring sets made of high grade cast iron for durability.
Note - These ring sets will not fit high-performance
aftermarket pistons (Arias, JE, etc.). Check your piston carefully before
ordering.
Piston, ring set, wrist pin and retaining clips for Kohler K-series and Magnum models K341/M16 (16hp; flathead) and K361 (18hp single cylinder OHV) cast iron block engines with a STD size cylinder bore of 3.750" (3-3/4"). Compression height is 1.7". Wrist pin is offset to reduce piston slap. Therefore, piston installs with notch facing flywheel. Ring sets made of high grade cast iron for durability. FYI: The biggest piston and rings set available for any Kohler engine is .030". If a .030" cylinder wall is in bad condition, then the cylinder will need to be sleeved back for a STD size piston and rings, or acquire another block (matching yours) with a cylinder wall in good condition.
|
Ring Sets for Kohler models
MV16, KT17, KT17II, KT19, KT19II, M18, MV18, M20 and MV20 flathead twin cylinder
engines with a STD size cylinder bore of 3.125" (3-1/8"). The Magnum
(M-series) engines have the new style forged Mahle pistons and rings. The
Mahle rings will also fit the old style KT-series cast pistons. Ring sets
for model KT21 are no longer available.
|
| NOTE: High-quality ring sets, pistons and piston/rings assemblies are also available for other makes & models of small gas engines. And the piston assemblies that we sell will work with a stock connecting rod and crankshaft without the need for rebalancing. And always match a billet connecting rod of a certain length to an aftermarket piston (Arias, JE, etc.) that has the correct compression height. These two parts must be matched for the piston to come flush with the top of the engine block, or have a few thousands of an inch pop-out. If using a Kohler connecting rod, the compression height may not be correct with an aftermarket piston (Arias, JE, etc.) that has the wrong wrist pin offset. The same is true with a Kohler piston and a billet connecting rod of a the wrong length. You can find piston ring compressors on eBay. |
| NOTE: Complete engine rebuild kits are available, but a kit will cost more than if the parts were ordered individually. So please contact me with a list of parts you need, and I'll get back to you with a total including shipping & handling. And if you need a part or parts that's not listed here or for other make and model of engines, please contact me and I'll see if I can get it at a reasonable price. |
Piston, ring set, wrist pin
and retaining clips for Kohler models K90 (3.6hp), K91 (4hp) cast iron block
flathead engine with a STD size cylinder bore of 2.375" (2-3/8"). Ring
sets made of high grade cast iron for durability. FYI: The biggest
piston and rings set available for any Kohler engine is .030". If a .030"
cylinder wall is in bad condition, then the cylinder will need to be sleeved
back for a STD size piston and rings, or acquire another block (matching
yours) with a cylinder wall in good condition.
OEM Mahle/Kohler. Pistons and
rings listed below Ê are the "new style"
forged Mahle design. (Narrow wrist pin spacing.) Mahle piston
and rings not available in aftermarket.
Aftermarket. Pistons and
rings listed below Ê are the "old style"
cast K-series design. (Narrow wrist pin spacing.)
"Popping" the Piston Out of the Cylinder -
"Popping"
the piston out of the cylinder a few thousands of an inch by offsetting the
bore in the connecting rod and installing bearing inserts, decking the block
or using a custom piston and connecting rod combination will improve air
flow and raise the compression ratio within the combustion chamber for more
power and torque. Remember, when popping the piston out of the cylinder,
there must a minimum of .030" clearance between the cylinder head and top
of piston! To determine the distance between the cylinder head and piston,
first measure the thickness of the compressed head gasket, and then subtract
.030" for clearance. It may be necessary to machine the underneath area of
the [billet] head directly over the piston to obtain the .030" safety
clearance. Also, the edge of the piston must be ground away for improved
combustion. See further below Ê.
If there's inadequate piston to cylinder head clearance, the piston will hit the head, without a doubt. If the engine is able to crank over and run, this will be evident by a loud tapping sound in the engine. A series of events will then soon happen:
|
Most 10hp (K241) pistons, and some other Kohler engines, don't come flush with the top of the engine block at TDC. Therefore, if installing bearing inserts and you want the piston to pop out of the cylinder a few thousands of an inch, the piston must first be placed in the cylinder without rings with a crankshaft journal at TDC, and then the piston height accurately measured. If you choose to pop the piston out of the cylinder, you must take into consideration the piston height and how far you want the piston to pop out of the cylinder. Example: If the piston comes within .020" of the top of the block and you want the piston to pop out at .020", then the big end of the rod must be offset-bored at .040". By the way - most competition pulling engines have the piston pop out of the cylinder.
The OEM head gasket has a compressed thickness of about .050". The piston and cylinder head needs to have a safety margin (clearance) of .030'. Therefore, with a milled head, the piston needs to pop out at a maximum of .020".
If you choose to use a piston and connecting rod combination that comes flush with the top of the cylinder, decking the block a maximum of .020" will allow the piston to pop out of the cylinder approximately .020". The stock head gasket is approximately .050" thick when compressed. Therefore, this will allow the .030" of the required clearance between the cylinder head and piston. In addition to decking the block, the valve seats will have to be re-done and proper valve lash adjustments must be made.
The compressed thickness of an OEM Kohler head gasket is about .050". The piston needs to have a safety margin of .030" due to rod stretch and crankshaft flex at very high rpm. And yes, when precision-balanced, even a cast iron crankshaft will flex a few thousands of an inch at high rpm without breaking.
The edge of the piston will have to be ground away with the piston in the block and connecting rod attached to the crankshaft. Otherwise, the edge may be too high or too low with the top of the engine block. And if the piston is going to be popped out just .020", there's no need to grind the edge away.
Removing Metal From the Edge of the Piston For Improved Combustion:
- Place the crankshaft in the block along with the bearing plate.
- With the rings off the piston, slide the piston, connecting rod with the bearing into the cylinder.
- Rotate the crankshaft so the piston is at the TDC position.
- Use a felt marker to place a line on the side of the piston next to the deck which face the valves.
- Remove the piston, and use a disc or belt sander to grind off the mark and grind an angled edge on top of the piston about 3/8" back. Create about a 30º angle or smooth the grinding so it'll blend in with the top of the piston. The grinding should resemble a "crescent moon" shape on the piston.
- Finally, use fine sandpaper to smooth and polish the ground edge.
Here's two interesting web sites: Arias Pistons (http://www.ariaspistons.com/) | J&E Pistons (http://www.jepistons.com/).
New high-performance piston and ring assemblies are available from Lakota Racing (http://www.lakotaracing.com/), Midwest Super Cub (http://www.midwestsupercub.net/) and Vogel Manufacturing Co. (http://www.vogelmanufacturing.com/). They offer them in various sizes and compression heights. They also make billet connecting rods to match the compression height of the piston and stroke of the crankshaft. |
The differences between the K241/M10 (10hp) and K301/M12 (12hp), K321/M14 (14hp), K341/M16 (16hp) flatheads and K361 (18hp OHV) Kohler OEM pistons, rods and crankshafts:
- The K241/M10 (10hp) piston have a compression height of exactly 1.62". The wrist hole diameter is .8596" (minimum/worn) -.8599" (maximum/new). Length of the connecting rod when measured from the centerline of each hole is exactly 5.558" in length. The crankshaft has a standard stroke of 2.875".
- The K301/M12 (12hp), K321/M14 (14hp), K341/M16 (16hp) flatheads and K361 (18hp OHV) OEM piston have a compression height of exactly 1.7". The wrist hole diameter is .8757" (minimum/worn) - .8760" (maximum/new). Length of the connecting rod when measured from the centerline of each hole is exactly 5.3" in length. The crankshaft has a standard stroke of 3.250".
- All the engines above È have the same deck height, which is exactly 8.625" (when measured from centerline of main radial ball bearings to top of block.)
What does "Compression Height" of a Piston Mean?
The
compression height is the measured distance from the top of the piston to
the center of the wrist pin. The stock 10hp Kohler piston has a compression
height of 1.62", and the stock 12 through 18hp Kohler pistons have a compression
height of 1.7". When the wrist pin is located lower in the piston (this is
known as "high compression height"), a shorter connecting rod must be used
with the piston for it to come flush with the top of the engine block.
Many
high-performance pistons have the wrist pin located closer to the top of
the piston. (This is known as "low compression height.") With a high-performance
piston with the wrist pin located closer to the top, a longer connecting
rod must be used with the piston for it to come flush with the top of the
block, or a slightly longer rod is used for the piston to pop out of the
cylinder a few thousands of an inch. The reason many professional engine
builders prefer to use a longer connecting rod is because they can pop the
piston out of the cylinder, plus reduce the friction that the piston skirt
places against the cylinder wall at very high rpm.
Why Having Proper Crankshaft End Play or End Clearance Is So Important -
On virtually any engine, crankshaft end play (clearance) is a few thousands of an inch when the crankshaft can move side to side (horizontal shaft engines) or up and down (vertical shaft engines). Inadequate crankshaft end play can have an effect on the crankshaft main radial ball bearings and engine performance.
Having proper crankshaft end play controls the stability of the piston in the cylinder, lessens wrist pin wear, lessens ring wear and it lessens connecting rod bearing surface wear on the crank journal. On a vertical shaft engine, if the crankshaft has too much end play, the piston will operate diagonally (at an angle) in the cylinder. This diagonal movement of the piston will cause the rings, wrist pin and rod bearing surface to wear unevenly and prematurely. But on a horizontal shaft engine, if the crank has too much end play, the piston and connecting rod will wobble side to side in the cylinder (much like the clapper in a bell). At high rpm, the crankshaft can move back and forth so quickly, the wrist pin in the piston couldn't react quick enough to compensate for the excessive movement. Also, on engines such as the cast iron block Kohler with helical (angled) teeth on the crankshaft and camshaft gears, too much crankshaft end play will effect the valve timing, which in turn will effect engine performance.
In a Kohler engine, insufficient
crankshaft end play will cause the main radial ball bearings to overheat
and "tighten up" and produce a "whine" or "howling" sound at higher rpms.
The overheated bearings could also cause the engine to slow down for no apparent
reason at high rpm when the [petroleum] motor oil reaches it's normal operating
temperature.
In an engine that has radial ball bearings as main radial ball bearings,
the steel balls in the main radial ball bearings turn the same speed as the
crankshaft. If there's insufficient crankshaft end play, and the faster the
crankshaft spins, the balls in the main radial ball bearings will spin just
as fast, and despite having quality lubricating oil in the crankcase, the
balls get hot, sometimes very hot. And the so-called high-performance aftermarket
11- or 12-ball main radial ball bearings operate even hotter. When this happens,
they swell a few thousands of an inch. If they swell too much, crankshaft
end play is taken up and crankshaft binding occurs, which effects engine
performance. This is why it's so important when rebuilding or building an
engine to set the proper crankshaft end play to specifications. I found that
the OEM Kohler 8-ball main radial ball bearings works better in either a
factory-stock or in a high-performance or high rpm engine. Just like the
factory-built Chevy V8 engines, Kohler engineers knew what they were doing
when they designed the internal parts for their engines.
A much lower cost alternative to using a machined aftermarket
billet aluminum bearing plate for a pulling engine is to make one from OEM
that's used on an older 10-14hp Kohler engine with the smaller 8" flywheel
and starter/generator. Use a
vertical metal bandsaw to cut the outer portion off (use
safety glasses and extreme caution!), then smooth any sharp edges. A bearing
plate made from OEM for a pulling engine may not look the best, but because
of the reinforced raised ribbing, it's just as strong to maintain proper
crankshaft end-play clearance. And besides, once the engine is installed
in the tractor, being the cut-out bearing plate is behind the flywheel and
under the safety shielding, no one will ever see it!
The gaskets on the bearing plate of a Kohler engine are also shims to adjust the crankshaft end play. Add or subtract gaskets until the proper clearance for crankshaft end play is obtained. Use a feeler gauge between the crankshaft and one of the main radial ball bearings or a dial indicator on the end of the crankshaft to check the end play clearance. To set the clearance, install one or two thick (.030") and/or one or two thin (.015") gaskets between the crankcase and bearing plate until the desired clearance is obtained. The end play on the 10-16hp flatheads and the 18hp OHV Kohler single cylinder engines is .003" (for very low rpm engines) to .020" (for very high rpm engines). Personally, I like to set the crankshaft end play anywhere between .012" - .020". I don't like the "closeness" of the .003" - .011" of clearance. The engines I build seems to turn freer at higher rpms with the little more clearance.
Sometimes when a Kohler engine is reassembled, it will take several gaskets to achieve the proper crankshaft end play. And as long as the bearing on the PTO end is fully seated and the crankshaft is more or less butted against the bearing, the [OEM cast] cam timing will be in perfect alignment.
Why Do Some Main Radial Ball Bearings Fit Tight on a Kohler Crankshaft and Others Have a Slip-Fit?
I've rebuilt many cast iron block Kohler engines through the years, and it
seems that with all of them, either the crankshaft main journals were machined
a few thousands of an inch different, or the main radial ball bearings were
machined different. Either way, with some engines, when installing the
crankshaft, I have to drive the crank into the bearing on the PTO side and
sometimes I have to drive the front bearing plate on, too. But with other
engines, the crank just slides into each bearing. Being a machinist, I know
that cast iron and steel contracts a few thousands of an inch in cool
temperatures and expands a few thousands of an inch in warm temperatures.
With this fact, being that Kohler's old manufacturing building(s) probably
wasn't insulated that well or at all, it would seem that Kohler machined
(ground) some of their crankshafts (and/or bearings) on a cool day during
the winter months and others were machined on a warm day during the summer
months. This would explain why there's a few thousands of an inch difference
with the main journals on their crankshafts. The Kohler engine blocks and
camshafts were probably milled or machined the same way. This is why the
camshaft and crankshaft need shimming to acquire the proper end-play. If
they were all machined exactly the same under controlled conditions, such
as with CNC machines, the parts would all measure exactly the same and no
shimming would be required. Either that, or the parts were machined on an
early Monday morning, or late Friday afternoon.
Back in the day when Kohler machined their cast iron engine blocks, camshafts and crankshafts, quality control wasn't as strict as it is today with the precision of CNC machines. The same is true with the Cub Cadet cast iron case transaxles, shafts and gears. That's why the camshaft and crankshaft require shimming (steel shims or various thicknesses of gaskets) to set the end-play clearances of either. And the ring and pinion gear teeth require [steel] shims to set the clearance and back-lash, and the tapered bearings need to be shimmed to set the preload. And as long as they're not bent or distorted, the shims can be reused with no problems. Nowadays, thanks to the precision of CNC machining, virtually all makes and models of engine blocks and transaxles don't require shims... for anything! As a matter of fact, many of them don't even use or require gaskets. They use silicone sealant instead (except for the head gasket(s) on the engines).
Anyway, to adjust the crankshaft end play, set it according to Kohler's specs. Use a heavy wooden or leather mallet to bump the crank back and forth so you can get a feeler gauge between the PTO bearing and crank to measure the end play clearance. And despite if the main radial ball bearings fit tight on the crank, as long as the end play is set right, the engine should run fine.
It's common knowledge that most
metals retracts (shrinks) a few thousandths of an inch when cool or cold,
and expends (swells) a few thousandths of an inch when warm or hot. Knowing
this, when building or rebuilding an engine, keep in mind that if the engine
parts are either cool or warm, the end-play clearances for the camshaft,
crankshaft, valves, piston-to-cylinder wall, etc., will vary according to
the temperature conditions the engine is being assembled under. According
to the manufacturer's clearance specifications, allow for slightly greater
clearances if the temperature is cool (when working in a shop that don't
hold heat well during wintertime), and for lesser clearances if the weather
is around 72° F. Actually, it's best to build or rebuild an engine during
warm weather with the engine parts warmed at room temperature at around 72°
F.
If all the oil were cleaned
from the Kohler crankshaft main [ball] bearings with cleaning solvent and
allowed to thoroughly dry, and then if the bearings were spun by hand, and
if the bearings isn't worn much or at all, they will make a rattling sound.
The noise isn't necessarily because the bearing is worn, the noise is caused
by the balls running dry on the races (metal to metal contact) because there's
no oil to separate the two. Apply a small amount of motor oil to the balls/races
and then spin the bearings by hand. They should be a lot quieter now. The
same thing will happen with new bearings. And if the bearings have very little
free play in them (about .005"), like they're worn, don't worry about this.
As the engine rpms increases and when the motor oil warms up, the balls in
the bearings will expand. Even new bearings have little play in them for
this reason. If all bearings, new or used, had no free play, as they get
warm up, the balls would bind in the races, lessening the performance of
the bearing.
Information About Using the Correct Connecting Rod for the Job -
If you've ever wondered about the differences between the early K-series connecting rods and the new style [Magnum engine] rods, the sides of the wrist pin hole on the new style rod are machined narrow so it can fit inside the new style forged Mahle piston. A new style rod will fit both the older K-series pistons and Mahle pistons without modification, but the K-series rod will fit only the cast K-series pistons. If you want to use a K-series rod with a Mahle piston, the sides of the wrist pin must be ground narrow so it'll fit inside the Mahle piston.
The best OEM connecting rod to hold up well above 4,000 rpm for use in a 12, 14 and 16hp engine is the one made for Kohler's 18hp OHV (K361) engine. The 18hp rods are much stronger than the 16hp (K341) rod, and more expensive. These rods should hold up well as long as the piston assembly and rod are precision balanced to the crankshaft's counterweights. Because no rod is indestructible when it comes to high speed out-of-balance rotating parts.
Advertisement:
| If you need a new or used connecting rod for your 10hp, 12hp, 14hp
or 16hp engine, or if you wish to have your 10hp-18hp connecting rod fitted
with bearing inserts, please contact A-1 Miller's Performance Enterprises
| 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
1-573-449-7347. E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
| NOTE: All parts listed here are NEW, unless otherwise stated. I do not sell cheap junk! As a matter of fact, most OEM Kohler parts are made in China now. Kohler owns some of the factories in China that make the parts. And most aftermarket parts are also made by Kohler in China. Kohler just place the part(s) in a generic box and sell them for less money. So when purchasing a genuine OEM Kohler part that comes in a box with the Kohler name on it, you're really just paying more money for the name. And as far as some parts being no longer available - either the parts didn't sell well or the EPA is trying to phase out parts for the old cast iron block flathead engines because they produce more air pollution than the newer OHV engines. |
|
There's "match marks" on both the rod and rod cap.
They MUST be aligned or "matched up" so the big end of the rod forms a perfect
circle around the crank journal when installed. Otherwise, if the cap is
installed backwards, the "perfect circle" will be egg-shaped or oblong, which
will bind on the crank journal. DO NOT over-tighten the rod bolts! Upon
installation, the oil hole in the cap faces toward the camshaft. And if the
threads strip out in a rod, then perhaps a longer grade 8 fine thread bolt
can be installed in reverse (the rod will need to be machined for head bolt
clearance) and use a grade 8 nut. If not, then the rod is scrap
metal. |
 NOS (New Old Stock)
connecting rods for Kohler K-series K90 (3.6hp), K91 (4hp) engine. These
rods are from dealer's old stock and no longer available from Kohler or any
other source. NOTE: The .010" undersize rod have a small hole drilled
through the beam section indicating it's .010" undersize. Crank journal must
be reground .010" undersize to match this rod.
|
 New connecting rods for
Kohler K-series models K141 (6¼hp), K160 (6.6hp) and K161 (7hp) cast
iron block flathead engines. These are plain aluminum bearing surface rods.
Bearing inserts are not available for these particular rods.
NOTE: The .010" undersize rods have a small hole drilled through
the beam section indicating that it's .010" undersize. Crank journal must
be reground .010" undersize to match this rod.
|
 New connecting rod for
Kohler K-series and Magnum models K181/M8 (8hp) cast iron block flathead
engines. These are plain aluminum bearing surface rods. Bearing inserts are
not available for these particular rods. NOTE: The .010" undersize
rods have a small hole drilled through the beam section indicating that it's
.010" undersize. Crank journal must be reground .010" undersize to match
this rod.
|
 New connecting rod for
Kohler K-series and Magnum models K241/M10 (10hp) cast iron block flathead
engines. Strong rods. Comes with long dipper. These are plain aluminum bearing
surface rods, but I can bore rod and install bearing inserts if you wish.
5.558" length. NOTE: These rods can be bored for installation
of STD size, .010", .020",or .030" undersize bearing inserts, and crank journal
must be reground to match diameter of undersize bearing inserts. The .010"
undersize rod have a small hole drilled through the beam section indicating
it's .010" undersize. Crank journal must be reground .010" or .020" undersize
to match the rod.
|
 New "one color" connecting
rods for Kohler K-series and Magnum models K301/M12 (12hp) and K321/M14 (14hp)
cast iron block flathead engines. Comes with long dipper. These are plain
aluminum bearing surface rods, but I can bore rod and install bearing inserts
if you wish. 5.3" length. NOTE: These rods can be bored for
installation of STD size, .010", .020",or .030" undersize bearing inserts,
and crank journal must be reground to match diameter of undersize bearing
inserts. The .010" undersize rod have a small hole drilled through the beam
section indicating it's .010" undersize. Crank journal must be reground .010"
or .020" undersize to match the rod.
|
 New "one color" connecting
rods for Kohler K-series and Magnum K341/M16 (16hp) cast iron block flathead
engines. These rods have a narrow wrist pin hole. Comes with long dipper.
These are plain aluminum bearing surface rods, but I can bore rod and install
bearing inserts if you wish. 5.3" length. NOTE: These rods
can be bored for installation of STD size, .010", .020",or .030" undersize
bearing inserts, and crank journal must be reground to match diameter of
undersize bearing inserts. The .010" under rod have a small hole drilled
through the beam section indicating it's .010" undersize. Crank journal must
be reground .010" undersize to match this rod.
|
 Used and in excellent
condition - ALCOA connecting rods for Kohler K-series K361 (18hp OHV) engine.
Also fits the K301/M12 (12hp), K321/M14 (14hp) and K341/M16 (16hp) engines.
These rods are no longer available from Kohler. Extremely strong rod. These
rods have a narrow wrist pin hole. Comes with long dipper. These are plain
aluminum bearing surface rods, but I can bore rod and install bearing inserts
if you wish. 5.3" length. NOTE: These rods can be bored for
installation of STD size, .010", .020",or .030" undersize bearing inserts,
and crank journal must be reground to match diameter of undersize bearing
inserts. The .010" undersize rod have a small hole drilled through the beam
section indicating it's .010" undersize. Crank journal must be reground .010"
undersize to match this rod.
|
 New connecting rods for
Kohler KT and Magnum models MV16, KT17, KT17II, M18, MV18 twin cylinder flathead
engines with a crank journal diameter of 1.3733"/1.3738". NOTE:
The .010" undersize rods have a small hole drilled through the beam section
indicating that it's .010" undersize. Crank journal must be reground .010"
undersize to match this rod. And new rods for models KT19, KT19II, KT21 are
no longer available. Also, the KT17 cylinders are different than the M18
cylinders because the OEM KT17 rods are narrower than the M18 rods. To make
the KT17 cylinders work with M18 rods, grind away (notch out) the lower portion
of the cylinders until the rods clear. Or acquire a couple of M18 cylinders
that's in good condition.
|
New connecting rods for
Kohler KT and Magnum twin cylinder engine models M20, MV20 with a crank journal
diameter of 1.4993"/1.4998". NOTE: The .010" undersize rods
have a small hole drilled through the beam section indicating that it's .010"
undersize. Crank journal must be reground .010" undersize to match this
rod.
NOTE: The alternative to using an undersize rod - If a STD size or .010" undersize rod is in good condition, the matching crank journal can be reground so it's perfectly round again and then if the original rod(s) isn't badly scored or burnt, it can be resized to fit to odd-size undersize journal(s). |
 Crankshaft Main Bearings
(Sleeve Flange Bushings) for Kohler KT and Magnum twin cylinder engine models
MV16, KT17, KT17II, KT19, KT19II, KT21, M18 MV18, M20 and MV20.
NOTE: Crankshaft main journal must be reground to .010" or .020"
undersize to match the .010" or .020" undersize bearings. Also, on these
engines, one main journal can be reground undersize if it's worn beyond specs,
and the other can remain STD size if it's within specs. Not available
in aftermarket.
|
Connecting rods for Kohler engine models K482, K532, K582 or K660/K662
have been discontinued from Kohler. But they can be purchased off of
eBay when they're available.
I don't stock these rods either. And with the crank journals reground .010",
.020" or .030" undersize, when the K532 or K582 connecting rods are bored
for installation of bearing inserts, certain undersize bearing inserts for
British MG car engines will fit the K532 and K582 rods perfectly. Contact
Elson Nichols of Loop 70 Auto Parts & Automotive Machine Shop, 14 Bus.
Loop 70 East, Columbia, Missouri 65201 USA. Phone: 1-573-449-0893. Email:
vjnen@centurytel.net. He can bore
these rods and install the MG bearing inserts for a reasonable price.
|
Crankshaft Main Bearings
(Sleeve Flange Bushings) for Kohler twin cylinder engine models K482, K532
and K582. NOTE: Crankshaft main journal must be reground to
.010" or .020" undersize to match the .010" or .020" undersize bearings.
Also, on these engines, one main journal can be reground undersize if it's
worn beyond specs, and the other can remain STD size if it's within
specs. Not available in aftermarket.
|
 Camshaft Bushing (Bearing)
for Kohler twin cylinder engine models K482, K532 and K582. Fits flywheel
end.
Bearing for the PTO end (part # 277039-S) is no longer available from Kohler and not available in aftermarket. |
Bearing Inserts and Machine Work for Connecting Rods -
|
Federal Mogul FP9885CP bearing
inserts available in STD size, .010", .020" and .030" undersizes.
$15.00 per pair, plus shipping & handling.
To identify this particular type
of rod, they look a lot like Kohler's 12hp, 14hp and 16hp OEM rods, but they're
of a very bright aluminum color. The word "ALCOA" and the numbers "45 564
01" (which isn't the correct part number) are embossed on the beam section.
If you're planning to use one of these rods in a 12, 14 or 16hp engine, just
remember that the crankshaft doesn't need to be rebalanced for use with it
because it weighs the same as the other OEM rods. But do have it fitted with
bearing inserts. But if you'd like to have them balanced anyway, it might
help the engine run somewhat smoother. Return
È
Most "part numbers" on Kohler connecting rods are meaningless. It seems that they're just random numbers that Kohler put on their rods. Why they did this, I have no idea.
The second best Kohler-made connecting rod to hold up to around 6,000 rpm
in the 12, 14 and 16hp engines are the ones made for Kohler's 16hp flathead
engines. They are of one color and the
superseded
part number for this rod is 45 067 24-S. This is for a standard size
rod. 
The correct part number
for a .010" undersize rod is 45 067 25-S. Most .010" undersize rods have
a small hole drilled through the beam section. These rods have a thicker
beam section which is suitable for wide open throttle operation (w/bearing
inserts) when rotating assembly is precision spin-balanced.. If a standard
size rod is used with an undersized crank journal, the engine will make a
loud knocking sound at operating speeds and eventually rod failure will result.
So be sure the rod is matched to the crank journal with proper oil clearance.
And it's highly doubtful that a two-color rod (light gray at the wrist pin
and dark gray at the crank pin) will hold up in a engine running at
wide
open throttle without a governor. But they seem to hold up very well
with no problems in ordinary governed engines running at 4,000 rpm. By the
way - any connecting rod that's going to be operated above 4,000 rpm should
be fitted with bearing inserts. Also, if an OEM or Kohler-type rod is used,
rebalancing of the crankshaft to the rod/piston isn't necessary. Aftermarket
or high-performance (heavier than stock) rods MUST be balanced to the
crankshaft's counterweights. If an engine isn't balanced for use with an
aftermarket rod, the engine will vibrate severely and eventually self-destruct.
Click here for engine balancing.
Torque the 10hp through 18hp connecting rod having the 3/8-24 bolts to 285 in. lb. or 24 ft. lb., and torque the studs w/nuts to 260 in. lb. or 22 ft. lb. For the cast iron block 7hp and 8hp engines, torque the rod bolts to 200 in. lb. or 17 ft. lb. DO NOT OVER TORQUE! And with the match marks aligned on the connecting rod and the cap, the rod goes in the cylinder with the oil hole in the cap facing toward the camshaft.
If a Kohler (or aftermarket) connecting rod have bolts (not studs w/flared
nuts) with a flat washer under the head bolts, replace them with split lock
washers of the appropriate size. After installing the rod in the engine,
torque the bolts with the split lock washer to
specs. The split lock washers
will guarantee that the bolts will not loosen over time. This is especially
important in an engine that runs at
wide
open throttle. But the flared OEM connecting rod nuts (w/studs) will
not loosen when properly torqued to specs.
There's
"match marks" on both the rod and rod cap. They MUST be aligned so the big
end of the rod forms a perfect circle around the crank journal when installed.
Otherwise, if the cap is installed in reverse, the "perfect circle" will
be egg-shaped or oblong, which will bind on the crank journal. And DO NOT
over-tighten the rod bolts, or the rod and cap will become distorted. If
this happens, the rod will need to be honed back to the proper dimensions
in a rod honing machine. And the oil hole in the cap faces toward the
camshaft.
Be
aware - as with any engine running above 4,000 rpm, there is no guarantee
that an OEM "one color" rod will not break. A "one color" rod only lessens
the chances of it breaking. Actually, it's best to use a custom-made billet
connecting rod and have the piston assembly and connecting rod precision
balanced to the crankshaft's counterweights. Click
here to learn about precision engine balancing.
How Bearing
Inserts Protect An Engine -
Due to lack of lubrication in
the crankcase, and/or at very high rpm, an ordinary aluminum bearing surface
connecting rod will most likely score the crank journal, and if the engine
is ran long enough with a loose rod, the rod will likely break, possibly
destroying the engine block. But an engine with bearing inserts, if the oil
is contaminated with dirt or metal shavings, or if the engine is ran low
on oil, out of oil or if the wrong viscosity is used (too thin of oil for
warm weather conditions or for high-performance use), as the bearings wear,
they won't score the crank journal like an ordinary aluminum bearing surface
rod will. In most cases, a rod with bearing inserts will knock, but rarely
cause the rod to break. If the engine starts knocking, turn it off immediately
and replace the damaged bearing inserts, and then install the proper grade/weight
of oil to the full level. Sometimes the bore in the rod can become oblong
or "egg-shaped" after taking a pounding from a worn bearing. If this happens,
it will need to be resized in a connecting rod honing machine to make the
bore a perfect circle again. If a new bearing is used in a rod with an oblong
hole, the bearing may fit too tight on the crank journal, causing it to get
hot while in use and possibly burn out from inadequate oil clearance.
With bearing inserts, the crank
journal may also wear, but most likely not wear. It'll also be wise to check
the rod for stress cracks with a strong magnifying glass or better yet, a
powerful microscope.
If a crank journal is worn smooth (not gouged or scored) and if the original plain aluminum bearing surface connecting rod, or even a new plain aluminum bearing surface rod is installed, the rod might knock, but it may last for several years under general yard work or for stock tractor pulling (4,000 rpms). However, the dangerous vibrating harmonics in the loose rod could cause stress cracks in the rod, eventually leading to rod failure. Bearing inserts cushions the impact or extreme pressure the rod places on the worn journal, which lessens the harmonics, allowing the rod to last longer.
As long as the crankcase is full of oil (splash oil lubrication system) or adequate oil gets to the bearings (pressurized oil pump lubrication system), and as long as the bearing inserts have the proper oil clearance, they should hold up to unlimited engine rpms. You'll also have more confidence knowing your engine has bearing inserts. Return to previous paragraph. È
Upon
installation of a connecting rod in a Kohler engine, the oil hole in the
cap faces toward the camshaft! There's "match marks" on both the rod and
rod cap. They MUST be aligned or "matched up" so the big end of the rod forms
a perfect circle around the crank journal when installed. Otherwise, if the
cap is installed backwards, the "perfect circle" will be oblong or "egg-shaped,"
which will bind on the crank journal. And DO NOT over-tighten the rod bolts
or nuts! If the threads strip out in a rod, then perhaps a longer grade 8
fine thread bolt can be installed in reverse to serve as a stud (the rod
will need to be machined for head bolt clearance) and use a grade 8 nut.
If this cannot be done, then the rod is scrap metal.
Connecting rods, rather being OEM or aftermarket (stock or high-performance), and despite how well-balanced the rotating parts are in a pulling engine, suffer a lot of stress at high rpm in a single cylinder engine. Therefore, if possible, before purchasing a used rod, it's best to look it over for hairline cracks with a strong magnifying glass or better yet, a microscope. And as I always say about buying anything off of eBay: BUYER BEWARE! So ask for a money-back guarantee, or you may have nothing but a piece of scrap metal on your hands.
If using a stock connecting rod above 4,000 rpm, an aluminum bearing surface rod should never be used. Because the extreme pressure and heat from the rapid rotation of the rod on the crankshaft journal causes the aluminum to swell and this could cause the oil clearance to lessen making the aluminum have contact with the crankshaft, minimizing the oil clearance, which will overheat and become scored, resulting in crankshaft journal/rod scoring or burning, engine seizure or even rod breakage. One way around this, if bearing inserts isn't available for your particular rod, is to have the rod surface enlarged an additional one thousands of an inch (.001") to allow for additional oil clearance (the extra .001" of clearance will not cause the rod to knock) and to make room for the aluminum to swell when it gets hot. Or if your rod can accept bearing inserts (10hp-16hp Kohler rods), have automotive-type bearing inserts installed, even if the rod is new or used, or if it has a relatively good bearing surface. The reason bearing inserts work best in high-performance or heavy duty conditions is because the soft babbitt material (lead) that's on the inserts can withstand extreme heat and extreme pressure. It also "cushions" the impact that the rod places on the crankshaft journal at high rpm. And it's still a good idea to have an additional .001" of additional oil clearance, even if bearing inserts are used. Using bearing inserts also strengthens a [stock] rod by cushioning the severe impact the rod places on the crankshaft at very high rpm.
If an aluminum bearing surface rod is scored or burnt on the crankshaft, the causes are either...
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|
No connecting rod in any 10hp-16hp K-series Kohler engine come from the factory with bearing inserts in them. The rod must be machined (bored and notched) for installation of bearing inserts. Kohler don't make bearing inserts for the connecting rod in any of their single cylinder engines. The bearing that's used in the rods are actually made for one particular model of Continental Engines, model 469 (4 cylinder). But the bearings fit the Kohler rod perfectly after it's been bored out. The bearings are available in STD, .010", .020" and .030" undersizes. Also, these bearings can only be used in Kohler engines with a 1.500" diameter crankshaft journal/crank pin (or undersizes), such as the 10hp through 18hp single cylinder engines and all of their twin cylinder engines with a stock (OEM) or an aftermarket connecting rod. No bearing inserts that I know of is designed for use in any other Kohler engines, except for the Kohler engine models K482, K582 and K682 if the crank journals were reground to 1.500". (STD size is 1.625".) The connecting rods would not need to be bored, being they are already 1.625" in diameter. But they would need to be notched for the tangs on the bearing inserts.
About Machining a Rod for Bearing Inserts -
FYI - Before I machine a rod for bearing inserts, I use a metal "plug" alignment tool that I made in my metal lathe to precisely align the big hole of the connecting rod with the centerline of the spindle in my milling machine. Then while the plug is in the rod, I firmly clamp the rod to the table of my milling machine and after leaving the big hole centered or moving the table offset for piston pop-out, I securely lock the table so the rod won't move in any direction. But for reasons unknown, sometimes the cutter/reamer will bore the hole in the rod slightly off-center between the bolts or studs. Whenever this happens, I grind away part of each bearing shell so they'll clear the rod bolt. I've talked to other machinist who bore Kohler rods about this and they tell me sometimes the same thing happens with them. But as long as the bearing shells are ground for clearance of the bolt, it poses no problems. |
For high rpm use, bearing inserts also need additional oil clearance. Therefore, it's good insurance to have the crank journal ground an additional .001" for extra oil clearance. As the rod and journal swell due to the rapid rotation of the two parts, metal to metal contact won't happen. Of course, it's a good idea to use full synthetic oil, too. And once a journal's been reground to exactly .010", it's awful hard to ground an additional .001" on it, making it .011" undersize. If the journal has been ground to exactly .010", the rod would need to be honed an extra .001" instead.
Sometimes an OEM connecting rod will need to be bored for installation of bearing inserts when the crank journal must be reground deeper than .010" undersize. (STD size and .010" undersize OEM connecting rods are the only two sizes that's available from Kohler.) But bearings are available in STD, .010", .020" and .030" undersizes, to match the reground journal. If your crank journal needs to be reground to .020" or .030" undersize, then undersized bearing inserts will need to be installed in the rod to match the diameter of the crank journal. Bearings can only be installed in the 10-16hp single cylinder flathead Kohler engines, the 18hp OHV single cylinder Kohler engine, the KT21 and M20 twin cylinder Kohler engine, because these engines all have a 1-1/2 diameter crank journal. Bearing inserts also help to provide longevity of the journal, just like in automotive engines.
More Information About Bearing Inserts -
For pulling applications, the oil clearance between the rod bearing and crank journal should be .0035" with ± .0005" for wear. This allows the .001" more clearance for rod swelling (when hot; only at high rpm). It'll be good to use this clearance for stock engines, too.
Bearing inserts provide a little more oil clearance to protect the crank journal. If checking the oil clearance with PlastiGage, and if it shows the clearance to be .0032"-.0035", don't worry about it. It'll work just fine. Many race cars run this much clearance. The rod won't knock either.
Boring a Kohler rod and installing bearing inserts in it doesn't weaken the rod whatsoever. Because whenever a rod breaks, 99% of the time they break in the beam section, not around the bearing area. And bearing inserts add very little weight. Meaning they don't upset the balance of the piston/rod assembly to the crankshaft's counterweights a great deal, even at very high rpm.
When the Connecting Rod Breaks or When an Engine "Throws a Rod" -
When the connecting rod breaks in an engine (due to either lack of crankcase oil or too high rpms), if you're lucky, no damage will be done to anything inside the crankcase except for a burnt crank journal and of course, a broken connecting rod. But if you're not lucky, the things to look for will be...
- After removing the oil pan, look at the bottom of the cylinder wall to see if there's a big chunk missing. If there is, the cylinder can be sleeved, or if installation of a sleeve is cost-prohibited, another [matching] engine block will need to be acquired. A small chunk doesn't matter as long as the skirt on the piston will be stable in the cylinder at Bottom Dead Center (BDC).
- Check the camshaft to see if it's broke in two. If the cam is bent, being it's made of cast iron, it's cracked and it'll break in two when tapped with a hammer. Also, check if there's a crack on the outside of the block where the cam pin goes into on the flywheel side. If there is a crack (due to the bent or broken cam), it can be welded up and the hole will need to be bored-aligned to match the centerline of the hole in the PTO side. This is to prevent slight bending of the pin, which would cause binding upon the installation of another cam.
- Look at the starter side of the block for a crack in the crankcase. If there's a crack, it can be welded up. But if there's a hole in the side of the block, and if you'll lucky enough to find the missing broke-out pieces, they may be welded back in the block. The same goes if the engine has a flat bottom oil pan.
-
Remove the flywheel and see if the keyway is cracked. If it is cracked, it
will need to be replaced. Do not attempt to weld the crack or repair the
flywheel in any way! It must not be reused because it will run out-of-balance.
There will be danger
of it splitting in two or exploding at higher rpms, which could cause
serious injury or death.
Installing bearing inserts in a rod for a Kohler engine would cost much less than purchasing a new or even used rod and/or crankshaft, even when used for non-pulling applications. Bearing inserts can be installed in new or used rods. They can also be installed in rods that's scored, has a heavily burnt surface (the burnt material will need to be bored out anyway to make room for the bearing), or even if the rod has a mismatched cap! If installing a mismatched cap, be sure to align the match marks, and it'll be best to resurface the sides of the big end on a sanding disc slightly (with the cap torqued to the rod, of course) to insure proper fit and side clearance on the crank journal.
By the way - We've reground MANY Kohler crankshafts to .020" and .030" undersize and installed bearing inserts in connecting rods and I have never had any problems with the crankshaft breaking, even when used in pulling competition when the engine turns at 6,000+ rpm. So it's a safe thing to do. Besides, I wouldn't have mentioned it here if it didn't work.
WHEN REBUILDING
AN ENGINE, NEVER, EVER INSTALL A CONNECTING ROD DRY! Always lubricate the
cylinder wall, piston rings, piston pin, bearing surface and crank journal
thoroughly with clean motor oil before installing! Failure to do so could
(or more likely, will) result in prematurely worn rings, piston, rod journal
damage or seizure, crank journal damage, a noisy and/or smoky engine and
possible engine block damage!
Advertisement:
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contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia,
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Bearing Inserts and Machine Work for Connecting Rods -
|
Ever wondered why there's longer-than-stock length custom-made connecting rods?
The reason many high-performance
engine builders prefer to use a longer, custom-made, billet [heavy duty]
connecting rod is because there's less pressure from the piston skirt placed
against the cylinder wall during high rpm. At high rpm, a long rod moves
or "swings" side to side with less force, while a stock length rod moves
more rapidly. Longer rods operate at less of an angle than shorter stock
rods do. Therefore, piston skirt "drag" or scraping and force against the
cylinder wall is greatly reduced and an engine will produce more rpm with
less friction resulting in more power. In order for an engine to accommodate
a longer rod, a special made light-weight piston with its wrist pin located
closer toward the top (wrist pin location is known as "compression height")
must be used. Many engine builders prefer to pop
the piston out of the cylinder a few thousands of an inch to help increase
compression. To do this, either offset bearing inserts are installed in a
stock rod, or a longer rod/custom piston combination is used.
Because billet connecting rods
are wider than OEM ones, each lower side of the cylinder wall must be ground
away with a small disc grinder so the rod will clear it. The minimum clearance
between the rod and cylinder wall is .050".
The billet connecting rod bolts should be torqued to 18 to 20 ft. lb. Overtorquing them could result in distortion of the big end of the rod.
NOTE - When used in a high rpm application, aluminum connecting rods develop "rod stretch" over time, which could lead to rod failure. Even if it's a custom-made one. So to be safe, measure a used rod against a new or a known good one, or replace it after several years of use. And the connecting rod in ordinary lawn and garden engines will outlast the rod in high-performance engines because there's less strain on them at 3,600 rpm.
And if you've ever wondered about this: the bolts and studs in Kohler connecting rods can be reused over and over. They're very durable. Besides, nobody makes replacement bolts or studs for Kohler rods.
When installing the connecting rod and piston assembly in your engine, it's very important that the hole in the rod cap face the camshaft for proper lubrication of the rod journal. If it's installed facing away from the cam, the rod could burn. Also, both the connecting rod and cap are machined to form a perfect circle around the crank journal. So make sure that you install the connecting rod in the right way because both the rod and cap must be matched for proper fit around the crank journal.
A knocking, rattling, loud tapping, scraping or "weird" sound coming from an engine can occur in several different places. Here are the most likely causes:
- Worn connecting rod and/or crankshaft rod journal. To check for a loose rod and/or worn journal, with the piston halfway in the cylinder, very gently rotate the flywheel (or crankshaft) back and forth by hand. If the rod/journal is worn, you'll feel it. You can feel when the piston comes up on the compression stroke by the resistance of the flywheel when rotating it. This is when it compresses air. And there'll be no resistance when the piston reaches TDC. So before or after it reaches TDC, this is when you can check for looseness of the rod on the crank journal.
- Loose fitting piston in the cylinder. To check for a worn or loose piston, with the cylinder head removed and the piston positioned at TDC on the compression stroke (when both valves are fully closed), forcibly move the piston from side to side by hand. If the piston has a lot of play, you'll hear a knock-knock sound.
- Too much crankshaft end-play. To check for this, grasp the PTO end of the crankshaft or flywheel with your hand and forcibly move the crankshaft back and forth. If there's too much end-play, you'll see it and hear it.
- Worn balance gear bearings. To check for worn balance gear bearings, first remove the oil pan, and then move the balance gears side to side by hand. They may not make any noise when moving them by hand, but if they're excessively loose, they will make noise with the engine running. These can be removed without removing the crankshaft or rod/piston. With them removed, the engine will not vibrate any more than before. A heavy duty, angled-shaped, expandable snap ring pliers is required to remove the snap rings that holds the balance gears in place. Be sure to remove the thrust washers and spacers (if present), too. Leave the stub shafts intact. They will not interfere with anything.
- A loose PTO pulley or electric clutch on the crankshaft. To check these, with the engine not running, grasp the pulley or clutch by hand and forcibly move it/them back and forth. If there's too much play, you'll hear it.
- A loose flywheel or worn Cub Cadet clutch disc will also cause a knocking or rattling sound.
- A loud tapping sound is mostly caused by a valve with excessive stem-to-lifter clearance. Sometimes on the 10-16hp flatheads and 18hp OHV engine, one of the adjusters in the lifter will back-off, causing a loud tapping sound. When this happens, the adjuster end can be replaced with one from a known lifter with a tight adjuster, or the entire lifter will need to be replaced.
- A scraping sound is caused by the flywheel, flywheel screen or starter ring gear making contact with the flywheel housing.
By the way - main radial ball bearings in a Kohler engine wear extremely little, if any at all, and don't require replacing. Although I have seen some that are obviously worn and needed to be replaced. And worn main radial ball bearings won't make a knocking sound. They'll make a rumbling or growling sound because the crankshaft and flywheel will be spinning out-of-balance and the engine will have a more than-usual-vibration.
Gaskets: Should Silicone Sealant Be Used or Not?
If the parts isn't warped (where metal is separated between the bolt holes), no sealant is needed on the gaskets. But if they are warped, it'll be best to apply Clear RTV Silicone Adhesive Sealant. To fix a warped part, resurface it on a flat belt sander, sanding disc, or a large, flat file. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for two reasons: being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean-looking repair job. It can't be seen between the parts.
Is Your "Fairly New" Aluminum Block Engine Leaking and Burning Oil?
If it's a vertical shaft engine, check for oil leakage around the sump cover gasket. Due to normal engine heat, sometimes the engine block will warp just under the cylinder on a single cylinder engine or the #2 cylinder on a twin cylinder engine. Part of the cylinder that makes contact with the sump cover will pull away from sump, creating an opening for the sump cover gasket to leak oil. This will create an air gap which allows outside air to be sucked inside the crankcase upon every upward movement of the piston(s). Then as the piston(s) travels downward, oil inside the crankcase blocks the opening. This constant buildup of excess air being drawn inside the crankcase will compress inside the crankcase and force the crankcase oil past the piston ring gaps and cause the engine to smoke and burn oil.
To fix this...
- Remove the engine and place it upside-down on a work bench.
- Remove the sump cover.
- Thoroughly clean the gasket material and all parts.
- Install a new oil seal in the sump cover. (The old one will probably leak from the sump being removed.)
- Apply a thin bead of Clear RTV Silicone Adhesive Sealant on the engine block. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for two reasons: being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean-looking repair job. It can't be seen between the parts.
- Install a new sump cover gasket on the engine block.
- Lubricate the crankshaft main journal and camshaft stub journal with motor oil to prevent damage due to a "dry startup."
- Apply the silicone sealant on the sump cover also.
- Reinstall the sump cover and torque the bolts to specs.
The engine shouldn't leak or burn oil now. But if it continues to use oil, perhaps it needs new piston rings.
What Type of Motor Oil Should Be Used? Top of page
Motor Oil Recommendation:
- SAE 30 works great for 40° F (5° C) and warmer temperatures. If used below 40° F, could cause slow cranking and hard starting.
- 10W30 or 10W40 for 0° to 100° F (-18° to 38° C) is better for varying temperature conditions. This grade of oil improves cold weather starting, but may increase oil consumption at 80° F (27° C) or higher.
- Full synthetic 5W30 for -20° to 120° F (-30° to 40° C). It provides the best protection at all temperatures as well as improved starting with less oil consumption.
- 5W30 for 40° F (5° C) and below is recommended for winter use, and works best in cold weather conditions.
- 20W50 is good for 32° F (5° C) and warmer temperatures. If used below 32° F, could cause slow cranking and hard starting. CAUTION! 20W50 oil is recommended in high performance or heavy duty application engines with an oil pump. Because sometimes when 20W50 oil is used in an engine with splash lubrication (no oil pump), as the rpms increase, the oil is thick enough so the dipper (on the connecting rod) will "cut a groove" through the oil instead of splash it up and thoroughly lubricate the internal moving parts. This could cause the engine to rattle or knock and possibly cause damage or excessive wear to the connecting rod on the crank journal and on the piston.
Motor oil technology have changed a lot since Kohler (and many other small engine manufacturers) published their oil recommendations 40+ years ago. In an older or freshly rebuilt air-cooled, lawn and garden engine with splash lubrication or if it has an unfiltered oiling system with no oil pump and/or no oil filter is used, it's best to use SAE 30 weight non-detergent motor oil. Non-detergent oil allows any impurities in the oil to settle to the bottom of the oil pan. Detergent oils suspends any impurities so the oil filter can better filter it. Detergent oils should be used only in engines with an oil filter. If an engine doesn't have an oil filter, it's best to use non-detergent oil for long engine life. If an engine is used during wintertime, and being there are no multi-weight or synthetic non-detergent oils available, the only option is the use 10W30 or 10W40 motor oils so the engine will crank over easy in cold weather to start fast. And be sure to change the oil when it's hot on a regular basis.
Multi-Weight VS Straight Weight Oils -
During the hot summer months, it's best to use SAE straight 30 weight oil to better lubricate and help cool the internal moving parts of the engine and to prevent velocity oil breakdown. Being the Kohler K-series and Magnum engines doesn't have an oil pump, which keeps a constant supply of oil to all moving parts, splash lubrication works differently. And it's harder to cool an air-cooled engine on a hot day. Automotive engines are liquid-cooled and they run a lot cooler. Therefore, they can make better use of multi-weight oils. Heavier SAE 30 oil doesn't thin out like multi-weight oils and it better separates the parts from having metal to metal contact, which cause premature wear. Actually, it's better to use full synthetic 10W30 or 10W40 oil in an air-cooled engine year-round. Full synthetic oil don't get near as hot as conventional petroleum oil. It maintains its velocity even during the hot, smothering summer days.
Rule of thumb is: Detergent oils should be used only if the engine has an oil filter. Because the debris in the oil is suspended in detergent oils, which can be filtered, with non-detergent oil, the debris settles to the bottom of the oil pan. But if the oil changed on a regular basis, detergent oils can be used in a non-filtered oiling system. What was mentioned above È is what most manufacturers suggest to use [non-detergent oil] in their non-filtered small engines, which does make sense. And you know as well as I do that nothing lasts forever in this world. And despite what kind of oil is used, eventually all engines will wear out sooner or later.
If you think about it, most pulling tractors don't run long enough (compared to race cars) to totally heat the oil and break it down so it's thin. But if it makes you feel any better, it's safe to use SAE 50 oil instead. Due to the extreme pressure of the internal moving parts at high rpm (above 4,000 rpm), don't use multi-weight oils such as 10W30 or 10W40. They could cause excessive wear, resulting in damage to internal parts. I've used SAE 30 at times then SAE 50 in our two Super-Stock tractors and have had good results with both oils.
But if you don't mind spending a few extra bucks, the best type of oil to use in a pulling application to use is full synthetic 10W40 motor oil. Test data shows that you can get a 1 to 2 percent increase in horsepower using full synthetic oil. There's also a less chance of a full synthetic oil leaking because it doesn't "thin out" as easily as conventional petroleum oils, especially under extreme heat conditions. Because extreme heat has little or no effect on chemical-based products such as full synthetic oil, Clear RTV Silicone Adhesive Sealant, etc., it doesn't break down like natural-based products sometimes do. Once you understand the properties of full synthetic oil vs conventional petroleum oil, you will never use conventional petroleum oil again. And either type of oil may need to be changed periodically if burning methanol fuel. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for two reasons: being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean-looking repair job. It can't be seen between the parts.
If an engine has a cooling system (air blowing over the cylinder's cooling fins by use of the flywheel fins or an electric fan), then it'll be okay to use a high grade conventional petroleum oil. But if there's no cooling system whatsoever, it'll be better to use a full synthetic 10W40 motor oil.
CAUTION! 20W50 oil is recommended in high performance or heavy duty application engines with an oil pump. Because sometimes when 20W50 oil is used in an engine with splash lubrication (no oil pump), as the rpms increase, the oil is thick enough so the dipper (on the connecting rod) will "cut a groove" through the oil instead of splash it up and thoroughly lubricate the internal moving parts. This could cause the engine to rattle or knock and possibly cause damage or excessive wear to the connecting rod on the crank journal and on the piston.
Synthetic oil is mainly used in high-revving and high-performance engines that operate at higher rpm for long periods of time because full synthetic oil won't get hot like conventional petroleum oil does, which protects the internal moving parts better. But mineral oil, which is more commonly known as conventional petroleum oil, is used in ordinary engines that will never operate at extremely high rpm for long periods of time.
Using a quality full synthetic oil will allow an engine to run cooler, operate smoother and last longer. The engine will rev up easier because there's less friction of moving and rotating internal parts. Conventional petroleum oils get hot (too hot to handle with bare hands) and their additives break down after a while, and if not changed regularly, sludge will form. Full synthetic oils never get hot. They stay cool to the touch the entire time the engine is running and their additives don't break down. Therefore, no sludge. It's really amazing how well full synthetic oils work. There's also a synthetic blend type of motor oil that's 30% synthetic and 60% petroleum. They don't offer the same protection that full synthetic oil do.
Full synthetic oils provide maximum protection, cooler operating temperatures, and longer engine life. No conventional petroleum oils can match the performance of full synthetic oils. Unlike conventional petroleum oils, full synthetic oils don't get hot. It stays the same temperature regardless of engine operating temperature. A race car mechanic once told me on different length tracks, they have to swap out the ring and pinion gears to be competitive against other race cars. After running on the track in a race, when they changed the gears and when they used petroleum gear oil, they had to wear gloves to handle the hot gears. Then they switched to full synthetic gear oil, and after running on the track in a race, and when they changed out the gears, they didn't need to wear gloves because the gears and oil was as cool as the day they installed it. And synthetic oil blends helps provide engine protection, cooler operating temperatures, and longer engine life. Not as much as full synthetic, but it does help.
Personally, I prefer Mobil 1 full synthetic motor oils because I've always had good results with them, heard good things about them from other mechanics and Walmart sells them for less money than other places.
FYI - Did you know that full
synthetic oil will not burn when poured on an open fire pit? Some brands
will smoke and some won't, but they won't burn like conventional petroleum
oil will.
Basic rule of thumb concerning the viscosity (thickness or thinness) of motor oil is this: Rub some between your finger tips. If it feels too thin, chances are it won't provide the needed protection for your engine.
Also, I think using oil additives to prolong the life of an engine don't do a thing. If oil refineries thought that an additive would help an engine last longer, they would put it in their oil. Additives is just something to get people's money, nothing more. What works best in an unfiltered engine (no oil pump/filter), is glue a small magnet at the bottom of the oil pan to attract steel or cast iron metal shavings for longer engine life. But make sure the oil dipper on the connecting rod doesn't make contact with the magnet!
Do Not Use "Oil Thickener" in a Kohler Engine! (A customer's experience that I like to share.)
I had a 14hp Kohler engine in my shop last summer (2013) that burned a lot of oil. The owner told me the engine was recently rebuilt by somebody else, but always smoked badly, so he filled the crankcase with "motor oil thickener". He said after a while the engine started knocking and rattling badly, but the smoking lessened. The owner said he drained the oil before bringing the engine to me. He said it ran out like honey or molasses! Anyway, he had me rebuild the engine and I found the connecting rod had wore the crank journal and the piston was also worn. I told him the oil dipper on the connecting rod must've cut a groove through the oil thickener and couldn't splash it around in the crankcase like conventional (petroleum-based) motor oil does to keep the parts well-lubricated. (Upon inspection of the piston rings' orientation, I found that the previous engine builder installed the second ring on the piston upside-down.)
Break-In Oils and Procedure for Ordinary (Lawn & Garden) Engines -
For proper break-in of a new or freshly rebuilt engine, use conventional (petroleum-based) SAE 30 weight motor oil containing an anti-wear additive, such as ZDDP (Zinc dithiophosphate), which place a protective coating between all internal moving parts, will get hot, create a wear pattern and produce a hardened surface, especially flat tappet lifters and camshaft lobes. Run an engine with aluminum cylinder wall(s) normally (up to 3,600 rpm) for 2 hours, or for an engine with cast iron cylinder wall(s), run it normally (up to 3,600 rpm) for 5 hours. Then drain the oil while it's hot, and either continue to use conventional (petroleum-based) SAE 30 oil, or switch to a quality 10W40 synthetic blend or full synthetic oil for warm weather use. Or use conventional (petroleum-based) 10W40 oil, or 10W40 synthetic blend or full synthetic 10W30 oil during cold winter use. Use no oil additives. Change the oil every 25 hours of engine run time or once a year. Synthetic-blend oils get about half as hot as conventional oils. But full synthetic oils don't get near as hot as conventional oils do. It's more slippery and remains cooler even after the engine have been in operation for several hours to better protect internal parts for longer engine life.
Break-In Oils and Procedure for Pulling Engines -
For proper break-in of a freshly built or rebuilt pulling engine, use conventional (petroleum-based) SAE 30 weight motor oil containing an anti-wear additive, such as ZDDP (Zinc dithiophosphate), which place a protective coating between all internal moving parts, will get hot, create a wear pattern and produce a hardened surface, especially flat tappet lifters and camshaft lobes. Run the engine normally (up to 4,000 rpm) for 4-5 pulls. Then drain the oil while it's hot, and either continue to use ordinary SAE 30 oil, or switch to a quality 10W40 synthetic blend or full synthetic oil. Use no oil additives. Change the oil every 25 pulls or once a year. Synthetic-blend oils get about half as hot as conventional oils. But full synthetic oils don't get near as hot as conventional oils do. It's more slippery and remains cooler even after the engine have been in operation for several hours to better protect internal parts for longer engine life.
And Remember... (added paragraph below on 7/13/14)
Rather if it's for competition pulling or for general yard and garden use, any fresh-built engine needs to fully break-in. Rings break-in quickly. But the valve faces needs to wear into the seats to seal in the compression 100%. The harder material the valves are made of, the longer it takes for them to "seat." Some pullers tell me that the engines I built for them run better every time they pull them. I remember a few years ago when I performed a valve job on my truck engine. It ran good, but I noticed it produced a little more power after 1,000 or so miles. This is because the valve faces wore into the seats, forming a perfect seal. So just to let you know, a fresh-built engine will not produce full power the first few times it's ran.
What makes crankcase oil to have a black appearance is caused by blow-by of the combustion process due to either worn piston rings, carburetor flooding or the engine running rich on fuel (gas). And if a carburetor floods or if the ignition timing is too retarded, the excess or unburned gas will seep past the piston ring gaps and into the oil, contaminating and diluting it. When oil becomes diluted, excessive internal wear will result. The gas will also break down the additives in the oil, causing sludge. This is why it's so important to have a "fine tuned engine" and change the oil regularly.
Oil Refill Quantities for Kohler Engines
| K90/K91 | K141, K160/K161, K181/M8 | K241A, K301A, K321A, K341A | K241/M10, K301/M12, K321/M14, K341/M16, K361 | KT17, KT17II, KT19, KT19II, KT21, M18, M20 | MV16, MV18, MV20 |
| 3/4 Quart | 1-1/4 Quarts | 1 Quart (narrow shallow/flat bottom pan) 1-1/2 Quarts (narrow deep sump pan) |
2 Quarts (wide base oil pan) | 3 Quarts w/filter | 2 Quarts w/filter |
Advertisement: (posted 3/3/13)
| If you need a quality oil filter, please contact A-1 Miller's Performance
Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA |
Phone: 1-573-875-4033. Please
call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no
answer, please try again later. (When speaking with Brian, please be patient
because I stutter.) Fax:
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|
  Oil Filters for Kohler engine models CH11 - CH15, CV11 - CV22,
MV16, KT17II, KT19II, M18, M20, MV18 and MV20, K482, K532 and K582. Kohler
part #'s 277233-S, 52 050 02-S1; Briggs and Stratton part # 491056 (Vanguard).
Has anti-drainback valve to minimize dry engine start. The advantage of
using a larger capacity oil filter is so it will allow for less scheduled
oil changes because the filter can hold more debris than an ordinary
filter.
|
If a small gas engine refuses to crank over, but is known to have the connecting rod intact and the piston moves freely in the cylinder, then either the starter motor is worn out or burned up, the battery voltage may be low, or if heavier-than-stock valve springs are used, the lever on the compression release mechanism could be broken. Or the ends of the tiny (hair-like) actuating spring on the compression release arms isn't connected. The compression release mechanism is an integrated part of the camshaft. It can't be replaced by itself. I wouldn't think it could be repaired either. So to replace the camshaft in any typical small engine on a garden tractor or lawn tractor...
- First drain the oil from the engine.
- Remove the hood/grille from the tractor (they're easy to remove), remove the muffler, PTO pulley, electric clutch, wiring and fuel line from the engine.
- Remove the engine from the equipment and place it on a sturdy work bench or table.
- Rotate the crankshaft so the piston is positioned exactly at TDC (Top Dead Center) on the compression stroke. This is when both valves are fully closed. Remove the valve cover to observe the valve movement when the crankshaft is being rotated. Run a long screwdriver or thin rod through the spark plug hole to feel when the piston is at TDC.
- Now position the engine upside-down and remove the bolts that secure the oil sump to the crankcase.
- Remove the oil sump, and then the camshaft can be removed from the engine.
- When installing a new (or good used) cam, be sure to align the match marks on both the cam gear teeth and crankshaft gear teeth! The crankshaft may need to be rotated for the marks to align.
- Reassembly is opposite of disassembly.
- Install a new sump cover gasket and the sump cover on the crankcase, and torque the bolts to specs.
- With the piston at TDC on the compression stroke, adjust the valves to specs and install a new valve cover gasket.
- Apply Clear RTV Silicone Adhesive Sealant on the gasket mating areas to lessen the chance of an oil leak. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for two reasons: being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean-looking repair job. It can't be seen between the parts.
- Install SAE 30 weight motor in the crankcase once the engine is reinstalled on the equipment.
If "piecing together" a 10-16hp cast iron block single cylinder
Kohler engine from various parts off of other engines, remember, the oil
dipstick and/or tube may not be the right one for a particular engine. I've
found several dipsticks and/or dipstick tubes that's not calibrated to certain
Kohler engines. Some are too short and some are too long. This includes the
ones that mount on the side of the block, next to the gear starter, or on
top of the crankcase, next to the cylinder, but not the one that mounts over
the cam gear (cam gear cover dipstick).
If the dipstick is too long or the tube is too short, the engine won't have enough oil in the crankcase, which could eventually lead to disaster. And if the dipstick is too short or the tube is too long, the engine will have too much oil, which could blow out the crankcase breather atmospheric vent hole at higher rpm. Also, make sure that the "end cap" or "stop cap" is properly positioned on the dipstick. If it slipped out of position from normal wear, this will give an incorrect oil level reading, which the oil level will actually be too low. If it did slip, the cap will need to be realigned (calibrated) and tack-welded back in place.
To fix a loose fitting oil dipstick tube, remove the tube, and use something tapered or a flared socket to spread the end of the tube slightly. Then before reinstalling the tube, apply high strength liquid threadlocker to permanently secure it in place in the aluminum holder.
Checking the Accuracy of the Oil Dipstick -
The engine is at full capacity of oil at 3/8" above the oil pan gasket for the 7hp and 8hp Kohler engines, and 1/2" above the oil pan gasket for the 10hp-16hp Kohler engines. If in doubt about the accuracy of the dipstick, hold the dipstick on the outside of the block with the cap (on the dipstick) even with the top of the dipstick tube or the threads on the dipstick even with the top of the crankcase (where the crankcase meets the cylinder) and then see if the FULL mark on the dipstick is at 3/8" or 1/2" respectively, above the oil pan gasket. If it's not, then an adjustment to the dipstick needs to be made. This method removes all guesswork. And always fill an engine with oil to the FULL mark on the dipstick.
But for a competition pulling engine, ask yourself these two questions: How many times does one have to add oil to a pulling engine? And as long there's no major oil leaks, why have a dipstick? Just know how much oil your engine holds, and have a way on the engine block to install the oil after every oil change.
In rare cases, the oil dipstick isn't accurate or calibrated right. I've had engines in my shop where the factory spot weld on the top of the dipstick broke loose, and the dipstick went all the way to the bottom of the engine. When the owner filled his engine with oil and checked the level, he thought it was full of oil, but really had far less then required. (This caused the rod to burn on the crankshaft.) And also, sometimes a dipstick will get lost (kids playing with the lawn mower) or get broken, and a wrong replacement is used, but it's not calibrated right like the original dipstick. Return È
Performing a Compression Test on a Stock or High-Performance Engine -
An accurate compression reading
can't be performed on an engine with an unaltered OEM camshaft due to the
compression release mechanism on one of the cam lobes. Depending on the make
and model of engine, the compression release is either a small lump (B&S,
some Tecumseh, etc.) or mechanical lever/pin (Kohler, some Tecumseh, etc.)
on one of the camshaft lobes that holds either the exhaust or intake valve
open about .050" while the piston is traveling halfway up in the cylinder
on the compression stroke. On OEM camshafts with a working compression release
mechanism and if the valves are adjusted to specs, the compression release
releases about half the compression from the combustion chamber at cranking
speeds. This is so the engine will start easier with fixed advanced ignition
timing. When attempting to start an engine with fixed advanced ignition timing,
if the compression release isn't working or if the valve (with the compression
release) have too much stem-to-lifter clearance (out of adjustment), the
engine will "kick back" every time.
There are two ways to perform an accurate compression test with a compression gauge on the Kohler K-series and Magnum models K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp), K341/M16 (16hp) flatheads and K361 (OHV 18hp) engines:
- On the flatheads, back off the adjuster for the exhaust valve so the compression release lever won't slightly open the valve.
- On the K361 (OHV 18hp), back off the exhaust valve rocker arm adjuster so the compression release lever won't slightly open the valve.
- Remove the cam gear cover, dislodge the ends of the tiny (hair-like) actuating spring on the compression release arms to disable the compression release mechanism.
- The compression test can now be performed with the engine under full compression.
To obtain an accurate compression pressure reading, perform the test with a fully charged battery, a starter that's in good condition and the throttle in the wide open position. Or with pull rope engines, place the throttle in the wide open postion. When performing a compression test with a gauge on an air-cooled engine, keep in mind that, depending on how the engine is built, the compression ratio or the compression pressure can vary from one engine to another. It depends on the size of the bore and stroke, the volume of the combustion chamber in the cylinder head, if the camshaft has a compression release or not and how much duration the cam lobes have. If a cam has a compression release mechanism, being approximately half the compression is released from the combustion chamber at cranking speed, the compression reading will be cut approximately in half.
When performing a compression test on an engine under compression, the 10hp Kohler can be from 98 to 150 psi. On a 12hp, it can be from 112 to 170 psi. On a 14hp, it can range from 120 to 190 psi. And on a 16hp, it can be from 127 up to 192 psi.
And cranking speeds, a long duration cam will relieve some of the combustion chamber pressure, resulting in a lower than normal reading. The more the duration, the lower the reading. Calculate the reading with the duration of the cam in the engine against the duration of a stock OEM cam. Example: If the compression pressure is 100 psi, multiple 100 by 285 (duration of cam that's in the engine) and then divide the answer by 223 degrees (duration of a stock OEM cam), which gives 128 psi.
How to Prepare an Engine for Wintertime or Long-Term Storage -
- First of all, prepare a cool, dry place of storage with low humidity to lesson the chance of corrosion and rust.
- Drain the entire fuel system from the equipment being stored. This includes the carburetor float bowl, fuel pump, fuel line, fuel filter and fuel tank. Leave the hose(s) disconnected so the entire fuel system will totally dry out.
- If the engine is equipped with an electric or mechanical fuel pump, apply about a teaspoon-full of clean automatic transmission fluid in the pump so the pump diaphragm will remain flexible or rotor vanes will won't stick and to prevent the poppet valves from sticking or becoming corroded.
- Remove the spark plug, squirt about a teaspoon-full of clean automatic transmission fluid (ATF) into the combustion chamber.
- Reinstall the spark plug and crank the engine several revolutions to evenly distribute the oil on the cylinder wall, valves, seats and valve stems (guides). (Automatic transmission fluid contains a rust inhibitors so the engine parts won't corrode or rust.)
- Run the piston up at TDC on the compression stroke. Doing this will prevent the valves from sticking open, and the valve springs won't be under extreme pressure.
- And that's all that's to it!
Removing the Variator from an Engine -
The variator (drive half of a torque convertor pulley system) is threaded onto the crankshaft PTO end by right hand threads. I had an engine that needed rebuilding with this in my shop a few years ago and I had one heck of a time getting the variator off. What I did, after removing everything as much as I could from the engine block including the oil pan, and after reinstalling the bearing plate to stabilize the crankshaft so it wouldn't break, I placed the block in my 12 ton hydraulic press, and placed a wooden block under the counterweights of the crankshaft to keep the crank from rotating when I try to loosen the variator. I placed light pressure of the press on the block just to hold it in place. After applying Liquid Wrench, then eventually used my acetylene torch on the crankshaft/variator threads, I used a large open end wrench with a "cheater bar" (long pipe over the handle of the wrench) to apply extra downward leverage to remove (unthread) the variator. I remember I had to grind the wrench narrow so it would fit the hex nut on the variator between the block and variator. I had to purchase an [older] wrench off of eBay because I couldn't find one reasonably locally or elsewhere online. Anyway, when the variator came loose, it made a loud "bang" sound, the block and press shook, and I thought the crankshaft had broke, but it didn't. The variator was loose.
Kohler Engine Service & Repair Manuals
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Advertisement. Machine Shop Services. (Prices below Ê are with the engine out of the tractor and on my work table.) Top of page
| If you need any of the services listed
below Ê performed, please contact
A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia,
MO 65203-9136 USA | Phone:
1-573-875-4033. Please call Monday-Friday (except Holidays), 9am to 5pm,
Central time zone. If no answer, please try again later. (When speaking
with Brian, please be patient because I stutter.)
Fax: 1-573-449-7347.
E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
Precision Dynamic Spin-Balancing Service. To balance a rotating assembly, I need the crankshaft, piston/rings, pin, clips, connecting rod and bearing inserts. The flywheel is balanced separately.
Engine Block -
Convert 10-16hp Kohler wide base block to narrow base, for use in a garden tractor requiring a narrow base engine block.
Valve Train Related -
Cylinder Head Work -
Crankshaft Repairs-
The Major Differences Between the K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp) and K341/M16 (16hp) Kohler Engine and Blocks -
Kohler engine blocks are not like the small block Chevy V8, they're not all the same. There are many other variations between the Kohler K241/M10, K301/M12, K321/M14 and K341/M16 blocks. If replacing an engine, the best thing to do is have the original engine rebuilt, then all the accessories will attach to the engine with no problems. But if the block is not rebuildable and damaged beyond repair, another block of the same type will need to be acquired. If interested in purchasing a bare block, please email me several detailed, sharp pictures of your block at various angles so I match it to one I may have in stock.
|
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Drill and tap two 5/16"-18
holes in exhaust flange (to mount header pipe). $40.00 labor, plus
return shipping & handling.
Resurface air-cooled small engine
cylinder head to remove warpage. $7.00 labor, plus return shipping
& handling.
Bare
Kohler K-series Engine Blocks (when available) -
Advertisement:
Miller's Engine Refreshing, Rebuilding, and
Build-up Service -
| If you need your engine rebuilt or built up for general yard and garden
work or competition pulling so it'll produce more power and torque, please
contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia,
MO 65203-9136 USA | Phone:
1-573-875-4033. Please call Monday-Friday (except Holidays), 9am to 5pm,
Central time zone. If no answer, please try again later. (When speaking
with Brian, please be patient because I stutter.)
Fax: 1-573-449-7347.
E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
| Engine Rebuilding Service -
I rebuild engines from ordinary stock up to 4,000 rpm governored pulling engines. I can rebuild your engine however you want. Just tell me know how you're going to use your tractor or equipment and I'll build your engine to suit your needs. If you wish to have me rebuild or build-up your engine, I'll need a list of what you want done to your engine or a copy of your club's pulling rules regarding the engine requirements before I can give you an estimate on the cost. I'll build your engine to the limit according to the rules, not less than what the rules allow. I also rebuild ordinary lawn & garden equipment engines too, such as cast iron and aluminum block single- and twin-cylinder flathead, OHV and v-twin Briggs & Stratton, Kohler, Tecumseh and 2-cycle LawnBoy. I've never encountered an engine I couldn't repair! Whenever I rebuild or build-up an engine, and if you wish to do so, I do whatever it takes so it'll produce the factory-rated horsepower or the maximum horsepower and torque, and last a long time. I go beyond what the repair manual says to do. I can get all the parts needed, too. I can build your engine so it'll be legal for the class you plan to pull in. And with my engine rebuilds and build-ups, you may not always win, but you'll look good trying! All customer's pulling engine builds are strictly confidential. This means your pulling competition will not know what goes into your engine!
Break-In Oils and Procedure for Ordinary (Lawn & Garden) Engines - For proper break-in of a new or freshly rebuilt engine, use conventional (petroleum-based) SAE 30 weight motor oil containing an anti-wear additive, such as ZDDP (Zinc dithiophosphate), which place a protective coating between all internal moving parts, will get hot, create a wear pattern and produce a hardened surface, especially flat tappet lifters and camshaft lobes. Run an engine with aluminum cylinder wall(s) normally (up to 3,600 rpm) for 2 hours, or for an engine with cast iron cylinder wall(s), run it normally (up to 3,600 rpm) for 5 hours. Then drain the oil while it's hot, and either continue to use conventional (petroleum-based) SAE 30 oil, or switch to a quality 10W40 synthetic blend or full synthetic oil for warm weather use. Or use conventional (petroleum-based) 10W40 oil, or 10W40 synthetic blend or full synthetic 10W30 oil during cold winter use. Use no oil additives. Change the oil every 25 hours of engine run time or once a year. Synthetic-blend oils get about half as hot as conventional oils. But full synthetic oils don't get near as hot as conventional oils do. It's more slippery and remains cooler even after the engine have been in operation for several hours to better protect internal parts for longer engine life. Break-In Oils and Procedure for Pulling Engines - For proper break-in of a freshly built or rebuilt pulling engine, use conventional (petroleum-based) SAE 30 weight motor oil containing an anti-wear additive, such as ZDDP (Zinc dithiophosphate), which place a protective coating between all internal moving parts, will get hot, create a wear pattern and produce a hardened surface, especially flat tappet lifters and camshaft lobes. Run the engine normally (up to 4,000 rpm) for 4-5 pulls. Then drain the oil while it's hot, and either continue to use ordinary SAE 30 oil, or switch to a quality 10W40 synthetic blend or full synthetic oil. Use no oil additives. Change the oil every 25 pulls or once a year. Synthetic-blend oils get about half as hot as conventional oils. But full synthetic oils don't get near as hot as conventional oils do. It's more slippery and remains cooler even after the engine have been in operation for several hours to better protect internal parts for longer engine life. And Remember... (added paragraph below on 7/13/14) Rather if it's for competition pulling or for general yard and garden use, any fresh-built engine needs to fully break-in. Rings break-in quickly. But the valve faces needs to wear into the seats to seal in the compression 100%. The harder material the valves are made of, the longer it takes for them to "seat." Some pullers tell me that the engines I built for them run better every time they pull them. I remember a few years ago when I performed a valve job on my truck engine. It ran good, but I noticed it produced a little more power after 1,000 or so miles. This is because the valve faces wore into the seats, forming a perfect seal. So just to let you know, a fresh-built engine will not produce full power the first few times it's ran. |
Below Ê are details and prices to rebuild your engine - FYI - Being I'm the only person to read and respond to all my customer's emails (about 20 or so per day), take my customer's phone call orders (about 20-30 on a nice day with good weather), with customers stopping by my shop, repair and rebuild my customer's parts and engines in my shop, order parts from my suppliers, process orders, package parts and then mail customer's parts at my local Post Office, etc., it may take me several months, possibly up to 6 months to rebuild an engine. I also have to depend on other local machine shops to balance engine parts, perform various machine work that I can't do myself. All this takes time. So please keep this in mind if you decide to have me rebuild/build your engine. Also, I don't like to rush on my customer's repair jobs. I'm very particular about my work, especially my engine builds. I like to take my time to make sure that everything is right, the engine will run right, produce full power and last a long time. I appreciate for you understanding my situation. - Brian Miller
| If you need your engine rebuilt or built up for general yard and garden
work or competition pulling so it'll produce more power and torque, please
contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia,
MO 65203-9136 USA | Phone:
1-573-875-4033. Please call Monday-Friday (except Holidays), 9am to 5pm,
Central time zone. If no answer, please try again later. (When speaking
with Brian, please be patient because I stutter.)
Fax: 1-573-449-7347.
E-mail:
pullingtractor@aol.com. Send
a message with Yahoo Messenger:
|
  Briggs & Stratton 3hp to 5hp flathead aluminum block
engine (horizontal or vertical shaft) rebuild to OEM factory specifications
@ 3,600 governed rpm (for general yard work only) Your engine.
Briggs & Stratton 7hp through 12.5hp single cylinder flathead aluminum block engine (horizontal or vertical shaft) rebuild to OEM factory specifications @ 3,600 governed rpm (for general yard work only) Your engine.
|
 Tecumseh 3hp to 10hp
flathead aluminum block engine (horizontal or vertical shaft) rebuild to
OEM factory specifications @ 3,600 governed rpm (for general yard work only).
Your engine.
|
 NOTE: If you wish
to have me rebuild or build-up your engine, I will need a list of what you
want done to your engine or a copy of your club's pulling rules regarding
the engine requirements before I can give you an estimate on the cost. I'll
build your engine to the limit according to the rules so the engine will
be competitive, not less than what the rules allow.
Kohler K-series and Magnum models K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp) or K341/M16 (16hp) cast iron block flathead engines Stock-Appearing engine build to the max @ up to 4,000 rpm (for heavy yard work or competition pulling). Your engine.
Kohler K-series and Magnum models K341/M16 (16hp) cast iron flathead block engine rebuild to OEM factory specifications @ up to 3,600 governed rpm (for general yard work or mild competition pulling). Your engine.
|
| Competition Pulling Engine
Refreshing Service
Ê
A typical pulling engine will last an average of 25 pulls or 3 years of
use. After that, it may start to lose power when under load and puff smoke
out the crankcase breather vent and/or out the exhaust. When this happens,
it's time for a refreshing job. This service is for competition pulling engines
that have been previously built, and needs the basic parts to revive the
power. It is not a complete rebuild.
Refresh Stock "Built to the max" 10-16hp 4,000± rpm Governored Kohler pulling engine. Includes install new rings or piston and rings; perform performance valve job; install new bearing inserts; clean, rebuild or rework/bore-out carburetor; install our reground 4,000 rpm torque camshaft; new gaskets and oil seals.
Refresh Hot Stock or Stock-Altered 12-16hp Kohler engine. Includes install new rings or piston and rings; perform performance valve job; new bearing inserts; clean or rebuild carburetor; if needed, install our welded up and reground Hot Stock/Stock Altered camshaft; new gaskets and oil seals.
Refresh NQS 30 c.i. Kohler engine. Includes install new rings or piston and rings; perform performance valve job; new bearing inserts; clean or rebuild carburetor; install new up-to-date Lakota, MWSC or Vogel camshaft; new gaskets and oil seals.
Refresh Missouri Super Stock 16hp Kohler engine. Includes install new rings or piston and rings; perform performance valve job; new bearing inserts; clean or rebuild carburetor; new up-to-date Lakota, MWSC or Vogel camshaft; new gaskets and oil seals.
Refresh 50.5 c.i. 16hp Kohler engine. Includes install new rings or piston and rings; perform performance valve job; new bearing inserts; clean or rebuild carburetor; new up-to-date Lakota, MWSC or Vogel camshaft; new gaskets and oil seals.
|
 Stock and Hot-Stock Class Competition
Pulling Engines
Ê
Top of page
The below are very powerful engines, and built and designed for competition pulling only, not general yard work. No charging system included. 10hp (K241), 12hp (K301), 14hp (K321) or 16hp (K341) Kohler engines built by Brian Miller. The "Built to the Max" Stock class engines runs at 4,000± governored rpm; has a 9-1/2" cast flywheel with majority of fins removed then dynamically precision spin-balanced; upper-mount gear starter; performance valve job with stock size valves; A-1 Miller's reground/torque cam; medium performance valve springs; #26 or #30 Kohler carburetor (depending on engine size) bored-out, reworked and set up for gas; enlarged ports and polished; 2nd or 3rd generation cylinder head milled .050"; connecting rod bored .020" offset for piston pop out with bearing inserts; header pipe and conventional Kohler point ignition system installed with ignition timing preset. The Hot-Stock class engines runs at wide open throttle (no governor); has a 9-1/2" 25 lb. steel flywheel; upper-mount gear starter; A-1 Miller's Hot-Stock welded-up and reground camshaft; high-performance valve springs; performance valve job with stock size valves; #26 or #30 Kohler carburetor (depending on engine size) bored-out, reworked and set up for gas; enlarged ports and polished; 2nd or 3rd generation cylinder head milled .050"; connecting rod bored .020" offset for piston pop out with bearing inserts; rotating assembly precision spin-balanced (to reduce engine vibration); header pipe and conventional Kohler point ignition system installed with ignition timing preset.
|
Custom-Built Cub Cadet Garden Pulling Tractors -
|
Briggs & Stratton Vanguard
V-twin aluminum block engine (horizontal or vertical shaft) rebuild to OEM
factory specifications @ 3,200 governed rpm (for general yard work or mild
competition pulling). Your engine.
Briggs
and Stratton cast iron block engine model 23 (newer models 231401-233461)
or model 24 (newer models 243431-243457) rebuild to OEM factory specifications
@ 3,600 governed rpm (for general yard work or mild competition pulling).
Your engine.
Tecumseh 8hp (VH80/HH80),
10hp (VH100/HH100), 12hp (HH120/OH120), 14hp (OH140), 15hp (OH150), 16hp
(OH160) & 18hp (OH180) flathead & OHV cast iron block engines (horizontal
& vertical shaft) rebuild to OEM factory specifications @ 3,600 governed
rpm (for general yard work only). Your engine. (Prices depends on size
of engine and extent of wear.)
Kohler K90 (3.6hp), K91 (4hp)
cast iron block flathead engine rebuild to OEM factory specifications @ 4,000
governed rpm (for general yard work). Your engine.
Kohler K141 (6¼hp), K160
(6.6hp), K161 (7hp) and K181/M8 (8hp) cast iron block flathead engine rebuild
to OEM factory specifications @ 3,600 governed rpm (for general yard work
or mild competition pulling). Your engine.
Kohler K-series K361 (18hp)
cast iron block single cylinder OHV engine. Rebuild to OEM factory specifications
@ up to 3,600 governed rpm (for general yard work or mild competition pulling).
Your engine.
Kohler K-series and Magnum
models MV16, KT17II, KT19II, M18, MV18, M20 and MV20 opposed cast iron twin
cylinder flathead engines. Rebuild to OEM factory specifications @ up to
3,600 governed rpm (for general yard work or mild competition pulling). Your
engine.
Kohler K-series engine models
K482, K532 and K582 opposed cast iron block twin cylinder flathead engines.
Rebuild to OEM factory specifications @ up to 3,600 governed rpm (for general
yard work or mild competition pulling). Your engine.
NOTES:
- A general stock engine rebuild includes: completely disassemble entire engine, clean and inspect all parts, bore (if it needs it) or deglaze cylinder, install new piston/rings/pin/clips assembly, regrind crankshaft journal (if it needs it), install new undersize (.010") connecting rod or bore rod for undersize bearing inserts (.020" or .030"; if it needs it), grind valves and seats, install new gaskets with Clear RTV Silicone Adhesive Sealant to lesson oil leaks, install new ignition tune up components, resurface cylinder head, clean and rebuild carburetor, clean commutator and lubricate bushings in gear starter and whatever else the engine may need so it'll run well and last a long time. By the way - I've always preferred to use Clear RTV Silicone Adhesive Sealant for two reasons: being it's an adhesive, it bonds parts together, forming a leak-proof seal; and being it's clear, it makes for a clean-looking repair job. It can't be seen between the parts.
- The engines I sell are turn key engines. I build all engines according to the customer's personal preferences for non-pulling purposes or to the customer's pulling club's sanctioning rules. "Build to the max" means engine will produce all the power possible and still remain stock-appearing externally. All of the above È will be performed in addition to the mild performance modifications.
- ± means more or less. This means if your engine needs minimal labor and/or machining, the price will be slightly less. But if it needs more than usual labor and/or machining, the price will be slightly higher. However, if it has sustained major internal damage or if it needs additional parts, extensive machine work and more labor, then the price will be even higher. And being I can't see your engine before you bring or send it to us, I can't honestly give an exact quote beforehand. But we'll treat you right and we'll try to keep the costs down as much as possible and still build you a quality engine so it'll start easy, produce full power and last a long time. The ± also depends on your personal preferences, parts needed and/or your pulling club's sanctioning rules. Also, if you wish to furnish some or all of the parts yourself, the price will be substantially lower.
- Before sending or bringing your engine to me, I don't need everything on it. Just the parts that can wear and need rebuilding or reconditioning, such as the gear starter, cylinder head(s), crankcase breather assembly, fuel pump and carburetor. I need the oil pan on it too, to prevent any dust and dirt from entering the crankcase after the rebuild. Please remove the sheet metal, too. I'll need the flywheel on the engine so I can set the ignition timing. A 50% deposit may be required on some engine rebuilds. Regular shop hours are 9:00 am - 5:00 pm, Monday-Friday, except Holidays. If you are traveling a great distance, it's best to call in advance (573-875-4033) to make sure that I will be here when you plan to stop by.
- All rebuilt engines returned (shipped) to the customer come with a 90 day workmanship warranty from date of pickup or delivery.
To place an order, please call or email me with your name, complete mailing address and phone number and so I can figure the total with shipping cost and USPS Tracking. All prices are based on a 2% cash discount. For payment, I accept cash (in person), Postal money orders, cashier's checks, MasterCard, VISA, Discover, American Express and Western Union Money Transfer. (If the engine and/or part(s) is/are for a specific purpose and/or make and model of tractor, your debit/credit card may be charged for the full amount or as a deposit right after your order is placed; please do not send your credit or debit card information in email!) Or you can pay me through PayPal. (My PayPal account name is my email address. And be sure to mention in PayPal a description of what the payment is for.) If sending a money order, please include a note in the envelope with your name, complete mailing address, phone number and a description of what the payment is for. My mailing address and phone number are below Ê. And I will send you the engine or parts as soon as I receive your payment or when the order is processed.
If you bring an engine to me in person, sit it in an automotive tire to keep
it from moving around during transportation. And please let me know first
so I can expect your arrival. But if you decide to ship your engine to me,
I don't need everything on it. Just the parts that can wear & need rebuilding
or reconditioning, such as the gear starter, cylinder head(s), crankcase
breather assembly, fuel pump & carburetor. I need the oil pan on it too,
to prevent any dust and dirt from entering the crankcase after the rebuild.
Please remove the sheet metal and PTO clutch/pulley, too. I'll need the flywheel
on the engine so I can set the ignition timing. Please send or bring your
engine when you're ready to the address below. If shipping it, the average
crated cast iron block Kohler engine weighs just under 150 lbs. Use this
web site to calculate the shipping cost for your engine:
http://www.shipgooder.com/.
Use FedEx Ground for dependability. Do not use a cardboard box alone!
Crate it well and any other parts with it securely so they won't get damaged
or lost in shipping. To construct the wooden crate, use 2x2's or 2x4's for
the frame work with a skid pallet on the bottom (so a forklift can pick it
up without damage) and 1/4" plywood or paneling as covering. Fasten the engine
oil pan mounting bolt holes to two sturdy 2x4's on the base of the crate
securely with 3/8" bolts. Use extra bracing on the sides and/or across the
top of the engine if needed to stabilize it in the crate. Use screws to fasten
everything. And be sure to include a note in a sealed plastic bag with your
name, complete and correct postal address, phone number, email address (in
case I have any questions) and a detailed description of what you want done,
how the engine will be used & any other parts you may need. When the
work is completed, I'll contact you with the total including return shipping
and handling. For payment, I accept cash (in person), USPS Postal Money Orders,
cashier's checks, MasterCard, VISA, Discover, American Express and Western
Union Money Transfer. (If the engine is for a specific purpose and parts
must be special ordered, full payment will be required right after your order
is placed or your debit/credit card will be charged for the full amount or
as a deposit.) Or you can pay me through PayPal. My PayPal account name is
my email address, and be sure to mention in PayPal a description of what
the payment is for. If sending a money order or cashier's check, please include
a note in the envelope with your name, complete mailing address, phone number
and a description of what the payment is for. My mailing address and phone
number are below. And I will ship your rebuilt engine/parts to you as soon
as I receive your payment.
To ship your engine to us, first off, do not use the US Mail Service, UPS or FedEx Express! We and our customers have had too many problems with them in the past. They wouldn't even make good on the insurance either. Their "gorillas" (employees) are trained in handling lightweight packages (weighing up to 70 lb.) and the heavier items tend to get damaged with their kind of handling. They are very hard on heavy packages when they handle them. The packages are placed on conveyor-belt systems and they seem to always drop the heavy ones off of the elevated conveyors, which usually destroys whatever is inside them.
We're authorized FedEx Ground (for anything up to 150 lbs.) and FedEx Freight (for anything over 150 lbs.) shippers because they've been proven to be the lowest cost, most gentle and reliable shipping companies. Here's a great web site that calculates freight charges. Go here: http://www.shipgooder.com/ and type in your zip code, our zip code (65203) and the crated weight of a typical complete 10-16hp Kohler engine (145 lb.). Shipgooder doesn't ship anything. It's web site just lets you see the latest cost of various shipping companies. Contact your local FedEx Ground for more details and to schedule a pickup. Or you can use a major trucking company with a good reputation for shipping heavy, fragile objects. Look in the Yellow Pages and ask around. The reason we say this is because we once returned a rebuilt engine that was crated very well to a customer using a well-known shipping company, and it was almost destroyed in shipping when he received it. You'll have better success with shippers such as FedEx Ground, FedEx Freight, Roadway, etc. Freight company employees are trained in handling heavy packages plus they use tow motors to move the freight around, not like UPS or FedEx Express with their uncaring "gorillas" unloading and loading the trucks. The approximate shipping weight of a crated 7 and 8hp Kohler engine is 100 lbs. And 10-16hp single cylinder cast iron Kohler engine is 145 lbs.
The Reason For Superseded Part Numbers -
When President Nixon was in office, he placed a price freeze on all products being manufactured in the US at the time. The manufacturers couldn't raise their prices even if it cost them more to produce their parts. What happened was the government placed the freeze on the part number of each part. So manufacturers simply gave their parts a different part number so they could legally raise the prices. Return To Previous Paragraph È
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