winterbeater
NAXJA Forum User
- Location
- Royal Oak, Michigan
I know that the FSM says that compression should be 120 to 150 PSI. The old standby used to be that you needed at least 100 PSI (for old beater motors), but I've also seen motors that wouldn't run at 100 PSI until they were re-ringed to raise compression back up. What is the lowest compression anyone has checked on a 4.0 that still runs good?