I plan to have the barrel off tomorrow and will weigh the piston to check balance tolerances. When I weigh it though, should I include the pin and rings, or just the piston by itself? Obviously the rings and pin come into play in the balance, but I wasn't sure what weight I want to use as the basis of comparison. Thanks!

Craig

email (option): cpdoberstein@gmail.com

I'd weigh it on it's own and then with the pin, the reason for this is that some of the pins are parallel inside and quite thick and some pins are tapered inside and tend to quite thin on the ends, which may give a noticeable difference.

email (option): davmax@ntlworld.com

Hi Craig..Yes, this will help you identify where the extra weight, if any, lies. In terms of overall crank balance the weight of the piston, rings, clips and pin must be taken into account.
Weight difference between the pattern piston assembly and the original should not exceed 1 1/2oz...If it does crank rebalancing or removal of material from the piston and/or substitution of a lighter gudgeon pin will be required (depending on the pin type fitted)...Ian

email (option): ian@wright52.plus.com

Thanks guys. I'll post results in a day or two...

email (option): cpdoberstein@gmail.com