honeing issues
I understand it a little different. The main thing is, as the exisiting rings wear, thhey rock slightly in the piston ring lands, and the pistons rock in the bores. That's why the bores go oval. What this creates is a rounded rigde from the worn bore surface to the untouched surface. New rings will always go right past it on the install because the ring compressor and existing chamfer let them move easy past it. Coming out, there is plenty of room, and no sharp edges on the rings or bore ridge, so they uslaully come out easy too. But when a new set of rings is put on, the sharp edge of the top ring hits the rounded edge of the wron side of the ridge. The rings can be broken, or fractured if the engine is run in that condition. I've always used a reamer to get very close, then the flex 3-stone hone to get rid of any ridge when I do ring and bearing jobs on high milage stuff.