compression ratio

Darren240z

Forum User
Hey guys!

I’m trying to work out my compression ratio on my engine, I currently have the head off and have taken measurements.

-n42 head 44.6cc
-260block 405.7cc
-Dished pistons 11.5cc
-1mm head gasket
-69mm stroke length

With my calculations it’s coming back with “4.8:1” which I think is wrong?

Could anyone give me an idea of what my set up should be around?

Thanks in advance :)
 

johnymd

Club Member
Mid 8's are correct. Put some flat top pistons in there along with a mild cam and your probably good to go. Keep it below 10.5 to avoid knock.
 
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