Reply To: Compression after new piston rings

[Don]

Did you check/clean the head bolt/block threads? Perhaps the threads are messed up and the bolts aren’t really tightening the head before reaching the 60-80PSI torque spec.
Why is it that you pulled the powerhead down and replaced the rings? Were the cylinders scuffed/scored? Were the rings stuck? Did you check the ring end gap like Tubs spoke of? How much did you “hone” the block? Over honing tends to leave the cylinders over size.
Hopefully, this is just a case of a bum compression gage. Or, perhaps the head/block needs resurfacing, bolts/threads cleaned up….I’m assuming you used a new head gasket. You should probably replace it again if you pull the head off.
Post some pictures if you pull the head again…
Like others have said, 20PSI is virtually nothing…..Can you feel some compression when you rotate the flywheel?