How to convert an engine's compression ratio to PSI (pounds per square inch):
(X*14.696)/1
(14.696 is standard atmospheric pressure at sea level.)
Examples:
Suzuki FA50 compression ratio is 6.5:1
(6.5*14.696/1 = 95.524 PSI)
Sachs A engine compression ratio is 8:1
(8*14.696/1 = 117.568 PSI)
Sachs D engine compression ratio is 10:1
(10*14.696/1 = 146.96 PSI)