RomRaider

This sheet only applies to 2618 forged pistons. This sheet is for those that build there own engines. As you know, machining and assembly should be done at 70*f. This is not always possible as most machine shops are not climate controlled. An engine assembled in cold weather can have to little PTW clearance if clearances were done per recommended clearance and not corrected for the temp of the part when machining is done. Same goes for an engine machined in hot temps. PTW clearances can be to much at lower temps and cause abnormal piston slap during cold starts and warmup.

Instructions:
Enter your piston diameter that is on the sheet provided by piston manufacturer. Enter requested piston to wall clearance. The sheet will give you your aim ptw clearance if machining and/or assembly is done at a temperature other than 70*f. All Machining and assembly should be done in a controlled atmosphere temp of 70*. This is not always possible as some machine shops are not climate controlled. You should always use the manufacturer recommended piston wall clearance.

This sheet will also give the theoretical PTW clearance at different temps if machining and assembly was done at 70*.

Enjoy.