[MikeK]

Following up on Jim Brierley's post about the top bore bevel, there is another problem:

Often the bore bevel or chamfer's depth exceeds the thickness of the thin top and bottom parts of that three-piece oil ring assembly. When you tap the piston down through your ring compressor those thin top and bottom sections are freed from the compressor at deck level and expand way up at the top of the bore chamfer. Now you're stuck.

I have experienced this quite a few times and my 'fix' was to take a waffled compressor (not the flat band type) and grind the band so the edge of the waffle is 45 degrees and sharp, not the original 90 which made it sit flat on the deck. With that 45 degree edge the compressor seats on the inside edge of the bore chamfer, below deck and permits those thin sections to pass easier.