How do you figure the weight of an engine piston at a certain RPM?

I am building an engine and the piston weight is more then the old one , I think I would need to figure centrical force but I do not know the formulaHow do you figure the weight of an engine piston at a certain RPM?
Umm, it weighs the same at any speed.





What you may be referring to is the forces on the con rod and crank/bearings, which has little to do with centrifugal force :-)


You're looking at a linear braking and acceleration, at each end of the piston travel, so you'd need to know how fast it's traveling up and down the bore... except that's not linear, since the crank is offet, so the piston speed varies over the length of it's travel.





You might want to try laying out a series of 1:1 drawings to get the dimensions involved, then go from thereHow do you figure the weight of an engine piston at a certain RPM?
What you need is a gram scale large enough for the piston to rest on. weigh each piston with rings .wrist pins and locks ( if equipped) record each piston weight (remember to # the pistons so not to mix them up) Use the lightest piston weight and adjust the other pistons to this weight by removing material inside the piston. A quality set of pistons are going to be close to the same weight . Now for a little advice,if your building this engine for street use and occasional dragging its not really worth the time and effort and the possible mishaps of removing more material than would be for safe operation.Take in consideration that this is a wet sump system and oil returns through drain holes in the valley , heads and slung off the cam and lifters. this oil gets slug around off the crank and onto the pistons causing each pistons weight to vary anyway.As far as the weight of the piston at diffrent RPMs ,the piston weighs the same at all RPMs except for the oil dropplets that land on it which you have no control over. Don't be concerned with matching the weight of your new pistons with the weight of your old pistons.