Compression Ratio ?'s
03-21-2005, 11:57 PM
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Compression Ratio ?'s Ok I have read the sticky on compression ratios but I just get confused and dont know what formulas to use. I have a 408 stroker motor I am putting together. It has 4.030 bore, 4.00 stroke, and -2cc flattop pistons. I will be using the .04 cometic head gaskets. My question is I am trying to get 11.5-11.7 compression ratio. I have 6.0L p.p. heads with the 72 cc chambers. What size chambers do I need for this compression. When I calculate it I come out with 64cc chamber gives me 11.5:1 comp. Is this Right? Any help would be great.
Thanks
Zach
Thanks
Zach
03-22-2005, 09:57 AM
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Your 72 cc chambers should be good for what you want.
It all depends on what your piston to deck measurement is, and what you meant by -2cc on the piston.
Are you at zero deck with 2cc valve reliefs?
Here's one calculator, and there are many out there.
http://www.torinocobra.com/Randys_tools.htm
It all depends on what your piston to deck measurement is, and what you meant by -2cc on the piston.
Are you at zero deck with 2cc valve reliefs?
Here's one calculator, and there are many out there.
http://www.torinocobra.com/Randys_tools.htm
03-22-2005, 10:22 AM
#3
Looks like you currently have 11.14 to 1
That is based on a 72 cc chamber, piston out of the hole .008, and a 9cc gasket volume...about .040 -.045 thick depending on diameter.
You would need a 68 cc chamber to achieve 11.66 (.018 mill)
Tony M.
That is based on a 72 cc chamber, piston out of the hole .008, and a 9cc gasket volume...about .040 -.045 thick depending on diameter.
You would need a 68 cc chamber to achieve 11.66 (.018 mill)
Tony M.