Mystery Piston?

I'm in the process of of overhauling a Continental A65 engine and I am trying to find some info on the pistons. They are five ring with part number 4597. Other markings cast into them are LC.EXLYNITE, REG. TM3ACOFA, and Patent 1799837 which is a patent for aluminum alloy.

I called TCM and the only info they had was that the part number is for a piston.

Anyhow, these pistons are in good shape and I'd like to re-use them but I'm wondering if they are a higher compression piston. I've done a bunch of Google searching and found that five ring pistons were used in A75s and A80s but no specifics on this particular part number.

Does anyone have any clues as to what I have here?

Drop this gent a note, explaining your situation. If he can't help, it can't be done.

harry@bowersflybaby.com

I'm just curious here Roger. Any chance your A65 has A75 pistons in it? I googled the bore, but could only come up with the A65 measurements.

Originally Posted by scuba72

I'm just curious here Roger. Any chance your A65 has A75 pistons in it? I googled the bore, but could only come up with the A65 measurements.

AS I recall, the A-65 and A-75 are the same engine, with a heavier-walled piston pin and a slightly larger carb bore and main jet, and the redline RPM goes up some. The A-80 had the five-ring high-compression pistons.

Dan

Originally Posted by challenger_II

Drop this gent a note, explaining your situation. If he can't help, it can't be done.

harry@bowersflybaby.com

Thanks guys. I sent Harry an e-mail. I've got this engine completely apart and I am cleaning and evaluating every little piece. Its in miraculous shape concidering its 60+ years old.

Well, Harry doesn't know what these pistons are either. He said they might be from a GPU or an A100. Anyone have a parts manual for an A100?

Try this company for manuals

Continental A100,C115&C125 Aircraft Engines Operation, Maintenance, Overhaul & Parts List

Dave

Mystery solved! The 4597 is the casting number. From this casting, 3 or 5 ring pistons were cut. They ink stamped the part number on the top of the piston--the ink stamp burns away after use. From the casting number and the fact that it has 5 rings, my pistons are part number 4638 which is in fact a documented part. This info came from a fellow at Fresno Air Parts. I called them on a tip from Harry.

Thanks everyone for the clues.