12-02-2018, 07:08 AM
It is not primarily reduction of gas pressure but the ring planing on the oil wedge on the upstroke which reduces pumping.
If large enough to admit significant gas, reduction of ring pressure would occur in both directions.
It means further loss of already very short skirt but a very small relief below ring could be added. Your club likely has old pistons to copy. With modern oils small drillings do not block.
If large enough to admit significant gas, reduction of ring pressure would occur in both directions.
It means further loss of already very short skirt but a very small relief below ring could be added. Your club likely has old pistons to copy. With modern oils small drillings do not block.