as the piston comes back down, the oil that scrapes off goes through those holes and helps in cooling, then lubing the top of the rod, not sure why his are so low, my wisecos had the same holes, but they were inside the oil ring groove, but mine were stroker fe3, so maybe mine are the oddballs...
Cause a .020 over piston wont fit in a stock block.
no shit... usually you bore the block base on piston, even though its .020 over, you might need to bore it out .015-.018 and hone the other .002. reason for doing that is most of this pistons expands base on temp. wiseco include the ring as a universal. you have to cut it to fit the bore and base the end gap on if its a drag or street car, nitrous or just boost. the regular piston ring are one size fit base on bore size. so if the machinist already bore your block to that size, then you might have too much clearance and the ring wont seat.
1990 mx6lx , f2, nitrous,...email@example.com on 87shot
1989 white pgt.. going for 600whp..1600cc inj
1990 probe gt 491whp at 29psi, holset hx35
1988 mx6gt 501whp @27psi..6262. now megasquirt
1990 mx6lx 348whp@ 18psi slipping clutch...sold