Stock Block
Thread Starter
Instructor
Joined: Aug 2003
Posts: 172
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Stock Block
Does anyone have info. re the stock block DECK HEIGHT ?(distance the piston is above or below the block surface at TDC) I'm trying to determine the resulting compression ratio BEFORE taking the engine apart. Thanks for input
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: Stock Block (bigjack)
It CAN vary fairly widely. This is one of the variables that make one stock engine in a thousand a real screamer. The piston .020" below deck is pretty average, however. Good luck, and...
RACE ON!!!
PS. Although I have no way of knowing, my guess is, that stock nominal compression ratios are calculated at something closer to a zero deck clearence. With casting variences in the combustion chamber size and deck clearence, I expect my 9.0:1 engine is closer to a true 8.0-8.5: compression ratio.
[Modified by CFI-EFI, 9:00 AM 9/28/2003]
RACE ON!!!
PS. Although I have no way of knowing, my guess is, that stock nominal compression ratios are calculated at something closer to a zero deck clearence. With casting variences in the combustion chamber size and deck clearence, I expect my 9.0:1 engine is closer to a true 8.0-8.5: compression ratio.
[Modified by CFI-EFI, 9:00 AM 9/28/2003]
