Hello, I am currently searching for parts for my engine rebuild, seems there's few ways to source .030" OS pistons for the 331. I e-mailed Falcon / Internal engine parts, inquiring tolerances on the pistons they sell. Couldn't get an answer other than they get their pistons from Kanter, saying that they keep trade secrets close to themselves... whatever that means regarding tolerances. Although, it is cast pistons, not hypereutetic or forged, so tolerances may be small. I would also like to know; how high is the lift on a stock camshaft for this engine, as i think about getting a ISKY 270 cam for more beef in the low RPM register. Any of you who can contribute with information regarding these topics ? Regards
You are dealing with a retailer. They probably have no idea of piston tolerance.. Aftermkt pistons can be made several different ways (sand cast, die cast, etc.) and clearance will vary by material, construction and final use.. Usually .0005"-.0015" piston to wall, is ball park on OEM factory type cast stock replacement pistons. But OD of pistons will vary if they are old stock. The new stuff is usually knatts azz with the CNC diamond tooling.. Try Egge. They can give you more info. .001" per inch is for forged pistons. a cast piston at .0035"-.004" will be very noisey and short lived.
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