Author Topic: Kohler opposed twin vs Briggs and Stratton opposed twin?  (Read 2180 times)

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Offline VICTORVIKING 713

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Kohler opposed twin vs Briggs and Stratton opposed twin?
« on: April 02, 2021, 06:29:48 am »
How are they different? Does the Kohler have the same issues as the Briggs and what are some upgrades that can be done to a Kohler Opposed?

Offline RoMow

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Re: Kohler opposed twin vs Briggs and Stratton opposed twin?
« Reply #1 on: June 12, 2021, 05:15:23 pm »
Victor, 

   I'm surprised no one has Replied to your question by now, but I'll try to help with what I know. 

   The Kohler opposed-twin engines have an aluminum crankcase with removable cast-iron cylinders that are held to the crankcase with six bolts each.  The Briggs & Stratton opposed-twin engines have a one-piece block where the cast-iron-liner cylinders are permanently made as part of the crankcase.  The heads of both engines bolt to the cylinders. 

   I personally prefer the Kohler engines, as I feel they are better engineered.  Yes, they're more expensive, but that is the result of the better engineering.  They're also more durable.   

   To use them for racing, the B&S governors are easier to remove to prevent internal disintegration when revved beyond the normal governed speed.  Kohler opposed-twin governors, on the other hand, require a lot of engine disassembly to access the governor-gear/flyweight assembly for removal.  But this is probably a moot point, as most racers will be disassembling the engine anyway. 

   As to upgrades, I'm not familiar with any commercially available ones.  My philosophy has always been that if I need more horsepower, I get a bigger engine.  Trying to circumvent factory engineering to gain more horsepower usually results in decreased durability.  Of course, there are always the standard tweaks such as porting and polishing the intake and exhaust passages; maybe stiffer valve springs to allow higher RPMs; larger carburetors; tuned exhaust system; etc.  And you can always groove the heads using Somender Singh's method which allows better combustion burn for more power.  (This will work on any L-head engine.) 

   Hope this helps...

Respectfully, 
Rodney Rom 
Rom's Reworks 
Butler, MO 
"No matter how many material possessions or awards you may acquire in your lifetime, the only thing you will ever truly own is your reputation." (Age 73)

Offline VICTORVIKING 713

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Re: Kohler opposed twin vs Briggs and Stratton opposed twin?
« Reply #2 on: June 26, 2021, 08:14:19 am »
Oh okay cool. Thankyou!

Offline BIG AL 202

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Re: Kohler opposed twin vs Briggs and Stratton opposed twin?
« Reply #3 on: June 29, 2021, 05:48:03 pm »
The Kohler is very heavy, The Briggs has a not so great oiling system but more parts are available.  Ya got to pick your poison. If your looking for lots of parts and less money, OHV Briggs.
ALWAYS VOTE FOR ED!   FONGS BROTHER FROM ANOTHER MOTHER!

Offline RoMow

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Re: Kohler opposed twin vs Briggs and Stratton opposed twin?
« Reply #4 on: August 01, 2021, 02:19:25 pm »
Victor, 

   I'm not sure what Al means by "very heavy" but there isn't that much difference in the weights of these opposed-twin vertical-crankshaft engines:
Specs: 
Engine                           "Shipping Weight"       HP      Cubic-Inch Displ.           Ft.-Lbs. Torque     Compression Ratio
Kohler  MV18 Magnum              130#                     18              42.18                    29.0 @ 2500 RPM              6.0:1
Kohler  MV20 Magnum              130#                     20              42.18                    32.7 @ 2500 RPM              6.6:1
B&S      422700                  110#-120#                 18              42.33                     28.5 @ 2700 RPM 
B&S      460700                  110#-120#                 20              45.60                     28.0 @ 2700 RPM 

   I don't consider a 10#-20# weight difference "very heavy."   

   I'm working on getting the compression ratios for the other Briggs' engines. 

   These figures also apply to the horizontal-shaft versions of these engines.  Note that the Kohler engines develop more peak torque 200 RPM sooner than the comparable-horsepower Briggs engines. 

   And I find it interesting that Kohler can get two more horsepower from the same displacement just by tweaking the internals, whereas Briggs has to increase the displacement another 3+ cubic inches.  And the 20 HP Briggs produces less torque than their 18 HP...

Respectfully, 
Rodney 
"No matter how many material possessions or awards you may acquire in your lifetime, the only thing you will ever truly own is your reputation." (Age 73)

Offline BIG AL 202

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Re: Kohler opposed twin vs Briggs and Stratton opposed twin?
« Reply #5 on: August 02, 2021, 01:16:29 pm »
I have only dealt with the cast iron twins. To be completely honest I didn't know about the aluminum ones. I do agree that Kohlers are better engineered. Learn something new all the time! I do know performance parts are harder to come by. I do know G-Team has a good dvd on building the Briggs oppy.
ALWAYS VOTE FOR ED!   FONGS BROTHER FROM ANOTHER MOTHER!

Offline RoMow

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Re: Kohler opposed twin vs Briggs and Stratton opposed twin?
« Reply #6 on: August 02, 2021, 04:11:38 pm »
Al, 

   Yes, that makes sense.  The one-piece cast-iron-block-with-cylinders K482 (18 HP - 47.7 CID) and K532 (20 HP - 53.7 CID) Kohler engines weigh 178 pounds.  I would also consider these "very heavy" for racing.  And these are horizontal-shaft engines, not available in a vertical-shaft version. 

Respectfully,
Rodney 
"No matter how many material possessions or awards you may acquire in your lifetime, the only thing you will ever truly own is your reputation." (Age 73)