how to determine valve overlap with comp

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Apr 3, 2006 | 05:28 PM

redtail2426

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From: Rochester,Ny

how to determine valve overlap with comp

I have a comp cam and on the cam card all the Ve's are measured at .006".Im not sure how to figure it out with that .Just want my overlap.

Apr 3, 2006 | 11:01 PM

Beast96Z

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From: Shreveport, LA

You don't need VE's to measure overlap. Take your .050" duration and plug them into this equation: Intake duration + Exaust duration divided by 4 - LSA = overlap at .050"

Apr 3, 2006 | 11:31 PM

Nate_Taufer

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Quote:

Originally Posted by Beast96Z

You don't need VE's to measure overlap. Take your .050" duration and plug them into this equation: Intake duration + Exaust duration divided by 4 - LSA = overlap at .050"

Almost, you just forgot to multiply the result x 2. So Intake plus exhaust duration at .050" divided by four. Then subtract the lsa, and multiply by 2.

So for my cam, 233+239=472...472/4=118...118-112=6...6*2=12...so my cam has 12 degrees of overlap at .050"

Nate