what would my compression be ?

[daves 72 dart]

What would my compression be with .030 over trw forged flat top pistons and j-heads.The compression is 11.2:1 with 57 cc chambers. I think! the j-heads have 72cc chambers.

[dave571]

Whats' the deck clearance?

Without that it's all a guess.

[daves 72 dart]

the deck is .046 below deck.

[ehostler]

OK, so you are .030 over. based on the heads, I know you are talking about a small block. Could you tell us which one?

The only way anyone can tell you the static CR is if you provide Bore, Stroke, how far down (or above) the piston is, Gasket thickness, and chamber volume. You've only given chamber volume.

[daves 72 dart]

ok lets see if i can get this right. the gasket thickness is .039,the engine is a 360 .030 over 4.030 bore,the stroke is 3.58,and it it .046 below dech the chamber is 72cc.thanks

[ehostler]

I did the math on 3 different calculators. All 3 show your current static CR to be 11:1. With the 72cc heads, they came up with a static CR of 9.33:1.

http://www.rbracing-rsr.com/compstaticcalc.html
http://www.csgnetwork.com/compcalc.html
http://www.angelfire.com/fl/procrastination/motor.html

For more calculators, just go to google and search for 'compression calculator'

[daves 72 dart]

thank you for the info.