Piston question

[Hellfrekke80]

There are two types of KB Hyper pistons: one with a D quench pad and one dished all the way around; these 944s have a D quench pad. I'm curious if anyone has encountered any issues, or if there would be any issues transitioning from forged to hyper pistons in terms of cylinder wall clearance.

[Russ Pottenger]

The short answer to your question is typically a Forged Piston has a bigger growth rate than a cast or hypereutectic piston and therefore requires more piston to cylinder wall clearance at room temperature to compensate for the growth rate.

The important part, and I think the basis of your question is that the clearance difference is built into the size or dimension of the piston. Meaning a .030/3.905 finished size 4 should have the proper clearance for either choice of piston. Cast/Hypereutectic or forged.

Hope that made sense. : )