Originally Posted by
Stewi
What I was trying to tell you in the PM is you CANT DO THAT. If your final bore is 87mm, your piston must be the same size, you dont order the piston a half millimeter smaller than the bore. Thats also why I said to bring your pistons to the machine shop so they can match the bores right. Tolerances in engine building are checked down to .0001 Thats one ten thousandth of an inch. So lets say you have 3 pistons that are dead nuts 87mm which is 3.4252" and then one piston is 3.4261. Your not going to bore all 4 cylinders the same bore if one piston is .0009 larger than the other 3. Look for pics of engines in process of being assembled, you will see the shop numbers each piston and rod, thats because each one is fit to its own cylinder, its own wrist pin and its own crank journal, it needs to be done like this because its the RIGHT way. If not it will fail.