Topic: Biulding a kohler engine

[Mike Kieffer]

I am kinda new to this game I ran a kohler mv18 last year and it was compleatly stock. this year I would like to try to get some more out of it. can anyone share some info with me on how to do that.

[JD Mike]

http://www.midwestsupercub.net/command.pdf

[Mike Kieffer]

Thank you for the link it looks like a great place for kohler v twin parts but the mv 18 is a apposed twin. I would like to get into a v twin in the near future but for now I must work with what I have.

[Caseracer]

I don't know of anyone making parts for the Magnum.  Precision Cams could probably regrind your cam.  Stiffer springs and better retainers could maybe be borrowed from another engine.  The hard thing about building this motor is the lack of parts.  One cool thing is the crank rods and pistions from a MV20 or M20 will bring you up from 42 to 47 cubes.  I believe it has tremendous potential but it will take alot of experimentation (time and money).  If you find parts for it let me know.  I have a couple MV20's and a MV18 I was planning to play with later.

Jack Jones
Hard Case Racing

[Wheelhorseracer]

I ran a Kohler Opposed MV18 In my first year. The big change was after I got a valve job done at Ryker Racing. I also shimmed the valve springs using a washer under the springs.

The big problem I found was fuel distribution.

I made a custom intake with different length runners to even out the mixture.



I also used a #26 Kohler carb as it has a high speed adjustment. Also.. I found mine made the most power as lean as I could run it without a stumble. The plugs read best that way.

I also had Ryan at Ryker Racing advance the timing.

[Mike Kieffer]

I have read on some other posts about useing the parts from an mv-20 and I have one of them kicking around somewhere. what is involed with that is that a big project? and as for the fuel dilivery I was kinda thinking that I would try doul carbs. but there again I have no idea where to start, what kinda carbs to use or even what size. I thought mabe some HL carbs from EC but I'm not sure.

[Wheelhorseracer]

You could easily run two Kohler #26 carbs with a straight off manifold. Easy to do as there is lots of room on this engine.

I even think two Walbro from a 15.5 OHV single engine might do the job.. EC builds lots of those.

I'm just thinking of cost savings.. If you are gonna rev yours you should think about a billet flywheel. Midwest should be able to help you there.. that is a BIG cast flywheel on there.

I ran my MV18 to 6000 rpm all season.. good engine.. just don't like the idea of that big flywheel coming apart at that speed.

[Caseracer]

The crank rod and pistons from the MV-20 are a direct bolt in replacement.  The bore is the same but a longer stroke.  That engine can be bored a bunch (over .250) if you can find pistons.  It's a cast iron jug so no sleeve is needed.  When I finish my current project I plan to build one for the Mod-X or C/P class.  It can easily be built to 56 cubic inches and the valves can be enlarged enough to feed it.  The biggest issue that I have found is the flywheel.  We would need to have one made for it.

Jack Jones
Hard Case Racing

[Mike Kieffer]

are the pistons the same in the mv-18 and the mv-20? becouse I put new .030 over pistons and rings in the mv-18 last summer with just a few races left to go, not much for hours on them. So could I keep the same pistons and ring and use the mv-20 crank and rods? or is the piston shorter or longer?