23-05-2020, 12:10 AM
Original pistons had rings 5/32 vertically and 1/16 radially? Many replacements were thicker which accentuated wear of the top groove. Sometimes remedied by tunring out for two thin, but a sign of high mileage.
If not unduly worn there is no law saying rings have to be replaced. Second rings are seldom much worn. The oil rings are not an odd size. A vague idea of cyl wear can be got from change of gap, taper typically about half the change. Can also file wire or nails and use as an internal gauge.If pistons are not split skirt the clearance is quite generous new.
Even if not seriously worn, the bores may not exactly suit available replacement pistons.
If not unduly worn there is no law saying rings have to be replaced. Second rings are seldom much worn. The oil rings are not an odd size. A vague idea of cyl wear can be got from change of gap, taper typically about half the change. Can also file wire or nails and use as an internal gauge.If pistons are not split skirt the clearance is quite generous new.
Even if not seriously worn, the bores may not exactly suit available replacement pistons.