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Case Compression, Let's Talk About It

Ketchup

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Man, there are so many hot girls on the internet and THIS is where I hang out. Anyway…

I’ve been thinking recently that case volume is a lot less important than compression duration.

Hypothetically, whether you shrink a 100cc down to 50cc or 150cc down to 100cc you’re still pushing 50 cc out.

But when you have a longer compression stage, the piston moves farther, so your compressing more CC before the transfers crack. So your compressing more volume no matter the total volume.

I’m not saying it very well. But I’m finding some real gains with a higher intake.

Still not sure how much ramping or staggering transfers effects case compression. Is a little bit open all that different from wide open?
 

Bjorn

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Man, there are so many hot girls on the internet and THIS is where I hang out. Anyway…

I’ve been thinking recently that case volume is a lot less important than compression duration.

Hypothetically, whether you shrink a 100cc down to 50cc or 150cc down to 100cc you’re still pushing 50 cc out.

But when you have a longer compression stage, the piston moves farther, so your compressing more CC before the transfers crack. So your compressing more volume no matter the total volume.

I’m not saying it very well. But I’m finding some real gains with a higher intake.

Still not sure how much ramping or staggering transfers effects case compression. Is a little bit open all that different from wide open?

Higher intake makes more vacuum in the crankcase before the piston open the intake, espesially if the crankshaft have stuffers.
 
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