Strange that the hot test is about 20 psi lower than the cold compression test.It should be more on a hot engine.What cams and valve clearances are you using?
I've seen 170 psi on a 9:1 engine 5 minutes after start-up after a rebore.I would suspect the compression gauge.
Detonation is usually caused by too much timing advance or too high compression ratio.Not enough revs can do it too,if the timing is fully advanced below about 3500 rpm.
I've seen 170 psi on a 9:1 engine 5 minutes after start-up after a rebore.I would suspect the compression gauge.
Detonation is usually caused by too much timing advance or too high compression ratio.Not enough revs can do it too,if the timing is fully advanced below about 3500 rpm.
