I am trying to figure out what compression ratio I want for a 383 build. I have the 350 4 bolt block, and the 400 crank, but still need to buy new 5.7 rods. I have a set of race pistons that I would like to use. They have a .400" dome. I am planning on some AFR's. I would like to be at 11:1. I'm assuming that a 78cc head, and some maching to the piston domes will get me close. Basiclly I need some one to do the math(which I am horrible at) and tell me where to look. I have done a few hours of looking and havent had any luck. And havent found an decent machine shop around here that is capable of help. I'm calling on those who like to flex their automotive knowledge.:hail: :hail:

 

You don't need a machine shop. If you have Corel QuattroPro or MS Excel, you can download this calculator, plug in your numbers, and see the results. There are also a few other calculators on other worksheets:

Engine Calculator.xls

 

here is a convienent performance calc page that includes a compression ratio calc

compression ratio calculator

You're going to need to know the volume of the piston dome.
And how far down in the bore the piston is at TDC.

You can calculate that if you know the "compression height" or "Pin height" of the piston. Check the manufacturers specs.

A stock sb chev block is 9.025" from crank centerline to the top of a cylinder bank. (deck height) if the decks have been milled than it will be less.

A "0 deck block" is 9.00"

 

Thanks, thats what I was looking for.