Help with C/R

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Oct 24, 2005 | 03:51 PM

ibgoatin

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Help with C/R

Sorry for asking , I've searched and can't seem to find the correct formula for figuring out compression ratio.

Here's what I'm looking at:

346 ls1 block
lq9 heads 72cc
-9cc dished mahle pistons

I'm trying to achieve somewhere between 8.5:1 and 9.0:1 for forced induction

Thanks

Oct 24, 2005 | 04:43 PM

iamsickofitall

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From: Clifton, NJ

http://www.c5frc.com/calculators/Com...Calculator.htm

not a problem - depending on what gasket you go with, it'll be between 8.8:1 and 8.5:1

Oct 24, 2005 | 05:39 PM

ibgoatin

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Thanks!

I plan on running the GM MLS gaskets.

Oct 24, 2005 | 07:35 PM

Beast96Z

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From: Shreveport, LA

Quote:

Originally Posted by iamsickofitall

http://www.c5frc.com/calculators/Com...Calculator.htm

not a problem - depending on what gasket you go with, it'll be between 8.8:1 and 8.5:1

Actually, that calculator won't read negative deck height. To get the correct compression you will need to use a calculator that reads negative deck height such as this one. http://www.rbracing-rsr.com/compstaticcalc.html Assuming a -.007 piston height, and a .064 MLS gasket, I get 8.68.1 compression. When you insert .008 into the C5frc calculator, you are entering .008 "in the hole". Positive numbers are in the hole, negative numbers are out of the hole. The C5frc calculator won't read past .0001 for zero deck.

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