Heymow - Lawnmower Racing Forum

Engine Help => Kohler Engines => Topic started by: cerialsledder on July 06, 2015, 05:19:36 pm

Title: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 06, 2015, 05:19:36 pm: I am running a governed stock class type mower. I was thinking of getting rid of the stock head gasket and making a thinner copper gasket to maybe up the ratio a tad. How thin of a gasket can I run for clearance reasons and how much compression will the stock connecting rod take before it go boom?

thank you in advance
Title: Re: How much can I up the compression on a stock CV490s
Post by: redline on July 06, 2015, 06:35:45 pm: It's not really stock after it's been modified, is it?
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 06, 2015, 08:06:49 pm: We were reading throughout the rules and there is nothing that states you can't up the compression ratio. We can run other carbs, exhaust headers.
Title: Re: How much can I up the compression on a stock CV490s
Post by: PJG56 on July 06, 2015, 08:14:52 pm: Doesn't sound stock with a modified head gasket!
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 06, 2015, 08:36:06 pm: I'll ask for sure tomorrow.
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 07, 2015, 06:54:27 am: Ok so I asked. Our rules are all over the place. They said when it comes down to it, you can do anything you want to the motor other than add aluminum parts. So with that being said does know what I could run for a copper gasket in the head thickness wise?
Title: Re: How much can I up the compression on a stock CV490s
Post by: redline on July 07, 2015, 07:52:52 am: What's the compressed thickness of the stock gasket?
Unless Kohler used a 3/4" sheet of plywood to make the gasket, you're really not going to gain much of anything with a thinner gasket.
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 07, 2015, 08:30:51 am: Not sure, I'll mic it when I head home on my lunch break today
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 08, 2015, 09:00:16 am: stock gasket isn't very thick. I think I would gain maybe an 1/8 of an inch. What about port and polishing? Anyone done this on a cv490?
Title: Re: How much can I up the compression on a stock CV490s
Post by: BIG AL 202 on July 09, 2015, 09:27:25 am: IF YOU ARE SERIOUS ABOUT BUILDING IT CONTACT "CROMWELL C4", THATS WHAT HE DOES!
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 10, 2015, 11:14:59 am: Quote from: BIG AL 202 on July 09, 2015, 09:27:25 am
IF YOU ARE SERIOUS ABOUT BUILDING IT CONTACT "CROMWELL C4", THATS WHAT HE DOES!

Yep got a hold of him and we going from there. I ordered stuff!!!! lol!! Thank you much!!
Title: Re: How much can I up the compression on a stock CV490s
Post by: PJG56 on July 10, 2015, 09:02:52 pm: Quote from: Soodude on July 10, 2015, 11:14:59 am
Yep got a hold of him and we going from there. I ordered stuff!!!! lol!! Thank you much!!

What happened to the "Stock Motor"????
Title: Re: How much can I up the compression on a stock CV490s
Post by: Cromwell C4 on July 11, 2015, 05:43:43 pm: Quote from: Soodude on July 07, 2015, 06:54:27 am
Ok so I asked. Our rules are all over the place. They said when it comes down to it, you can do anything you want to the motor other than add aluminum parts.
Title: Re: How much can I up the compression on a stock CV490s
Post by: BIG AL 202 on July 13, 2015, 10:25:19 am: WHAT THE HECK DOES THAT MEAN?
Title: Re: How much can I up the compression on a stock CV490s
Post by: cerialsledder on July 14, 2015, 03:41:22 pm: That means as long as we not adding billet aluminum parts then I guess we are good lol!!!!
Title: Re: How much can I up the compression on a stock CV490s
Post by: BIG AL 202 on July 15, 2015, 10:36:54 am: NO BLOWER FOR YOU YOUNG MAN! LOL