Author Topic: How much can I up the compression on a stock CV490s  (Read 5387 times)

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Offline cerialsledder

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How much can I up the compression on a stock CV490s
« on: July 06, 2015, 03:19:36 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



Offline redline

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Re: How much can I up the compression on a stock CV490s
« Reply #1 on: July 06, 2015, 04:35:45 PM »
It's not really stock after it's been modified, is it?
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Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #2 on: July 06, 2015, 06:06:49 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. 


Offline PJG56

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Re: How much can I up the compression on a stock CV490s
« Reply #3 on: July 06, 2015, 06:14:52 PM »
Doesn't sound stock with a modified head gasket!
Paul Guptill  (oppy) #238modX
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Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #4 on: July 06, 2015, 06:36:06 PM »
I'll ask for sure tomorrow.

Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #5 on: July 07, 2015, 04:54:27 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?

Offline redline

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Re: How much can I up the compression on a stock CV490s
« Reply #6 on: July 07, 2015, 05:52:52 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.
Ed King

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Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #7 on: July 07, 2015, 06:30:51 AM »
Not sure, I'll mic it when I head home on my lunch break today

Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #8 on: July 08, 2015, 07:00:16 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?

Offline BIG AL 202

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Re: How much can I up the compression on a stock CV490s
« Reply #9 on: July 09, 2015, 07:27:25 AM »
IF YOU ARE SERIOUS ABOUT BUILDING IT CONTACT "CROMWELL C4", THATS WHAT HE DOES!
ALWAYS VOTE FOR ED!   FONGS BROTHER FROM ANOTHER MOTHER!

Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #10 on: July 10, 2015, 09:14:59 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!!

Offline PJG56

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Re: How much can I up the compression on a stock CV490s
« Reply #11 on: July 10, 2015, 07:02:52 PM »
Yep got a hold of him and we going from there. I ordered stuff!!!! lol!!  Thank you much!!

What happened to the "Stock Motor"????
Paul Guptill  (oppy) #238modX
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Offline Cromwell C4

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Re: How much can I up the compression on a stock CV490s
« Reply #12 on: July 11, 2015, 03:43:43 PM »
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. 
Tyler Cromwell - Cromwell Racing Engines - Specializing in Briggs Vanguard and Kohler Command V-twin engines, and Honda/Clone singles from mild to wild! Built to win, Engineered to last.

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Offline BIG AL 202

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Re: How much can I up the compression on a stock CV490s
« Reply #13 on: July 13, 2015, 08:25:19 AM »
WHAT THE HECK DOES THAT MEAN?
ALWAYS VOTE FOR ED!   FONGS BROTHER FROM ANOTHER MOTHER!

Offline cerialsledder

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Re: How much can I up the compression on a stock CV490s
« Reply #14 on: July 14, 2015, 01:41:22 PM »
That means as long as we not adding billet aluminum parts then I guess we are good lol!!!!

 

anything