Quote:

Pressure gets trapped between the top and second ring and at higher rpm's this can cause the top ring to unseat if the pressure can't escape. So by running more clearance on the second ring it allows the pressure to escape.



Thanks, that makes sense, so when running Total Seal gapless second rings, just use a large top ring gap?
Also, while we're discussing this phenomenon, when builders drill the top of the piston for ring seal, wouldn't that promote the same type of seating issues due to the higher pressure between the rings and a lower pressure behind the top ring during, say, the early portion of the compression stroke?