so i got this kit. http://www.1977mopeds.com/product/50293/Puch-70cc-77-Reed-Kit/ the casting was straight for the most port, hard to do some clean-up on the transfers and on the exhaust port bridge. nothing more then a half an hour or so. when i put the cylinder on there with 1 base gasket, the top piston ring is visible through the exhaust port. i have to space this up with like 3.5-4mm to get piston fully clear of the exhaust port at BDC. this leaves some meat up top that fucks with my squishband, but i'll deal with that later.
but now as i'm getting closer to sealing it up and heatcycling and breaking it in i got some questions. this kit has a bridged exhaust, i think i should drill some holes in the piston to help cool this bridge. how do i do this?
it's gonna be going on an e50 with an unstuffed crankworks crank, with that pietcard 3055 and 2013 box combo pieced together from mopagan and treats, a 21mm phbg, boyesen dual stage reeds, braced 3 shoe with closed bell and a sidebleed weakends pipe. hoping for 55mph at 9250rpm 16x35 with uphill ability(110 pound rider).
will i have to do any other piston drilling to help cool the piston down or the rings? maybe some BBF tech? i need your opinions.