the vavles should never hit the piston. is sounds as if your timing is off. it the timing is off in the engine the valves will open to early or close to late causing them to contact the piston. i would check the timing. also check to make sure the timing cahin is not stretched. if it is, it could cause enough slack to allow some slight contact. a new piston will not solve anything, it is something other than the piston causing this to happen. i am running a 426 with the old stage 2 hotcam with a wiseco piston with no probems in over 3 years. It is not the piston, but somehting in the valve train.
Tyler Jones
2000 426EX, 11:1 wiseco, hot cams stage 3 "stroker" cam, Ported head done by Dr. G, FCR 41, Hot rods crank, running no base gasket, 1 layer of 3 layer head gasket, Klotz 113 race fuel Feather carbon smoothie hood, works tripples w/ressies, Black HMF slip on, AC pro peg nerfs, Azonic fat bars, burgaurd +1 1/4" swinger, Lonestar +1 stem, douglas yellow label front wheels, Pro Armor front bumper, + some others goodies
AIM: Fourtrax426
Holeshot Motorsports Wilder, KY
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