Compression test = Compression Ratio
 

Does anyone have a what a new engine build's compression reading (test) should be based on determined Compression Ratio assuming ring gap is optimal?

Closest thing you'll find is some dynamic compression ratio calculators will give an approximate cranking compression number,but it is'nt an exact science,more like a ballpark number.

Actual results will vary.

Just too many variables to say X engine with Y hardware will give Z cranking compression numbers,,,and get the numbers right 100% of the time.

Here is a DCR calculator that gives approximate cranking numbers.

http://www.wallaceracing.com/dynamic-cr.php

HTH.

Thanks for the link. Yup I see now with what you describe... not easy for a straight forward calculation.