What is the recommended formula for piston-to-bore clearance for an alloy piston in an air-cooled diesel? X thou per inch diameter, sort of thing.
For the Aussies, this is a Southern Cross ET-B, 2.5 hp @ 1500 rpm. There is no figure given in the recently published Southern Cross book.
I am setting up such an engine as a 32 volt lighting plant for our Club. It is part of a set of 3 engines donated to the club by a recently deceased member's family, and I have undertaken to prepare it for presentation at the upcoming Royal Show. The engine starts and runs but grabs after a few minutes. A few minutes later, it becomes free again and will restart. It was previously overhauled, but I suspect the piston clearance is insufficient. I have not yet pulled the piston. It does smoke quite a bit, too.
Jack in Oz