What Is This Off?

Great info Pete, thankyou very much.

Packard starters rotate the other way and have a gear instead of a splined shaft, although Rolls-Royce also adopted the same system on later engines, but yours is a U.S. Made Eclipse motor with a Packard reduction gear.

Pete

Wow Pete, thats a great find then.
How do they differ from the British Merlin??

It’s a starter for a Packard Merlin.

Pete

Looks like the cooling system header tank filler cap on a Hawker Demon but…its not:(

Would have to be cooling system in brass, all that weight on an aircraft could only be justified by corrosion considerations.

A nice lecture in electrolytic corrosion between the aluminium sacrificial anode and brass body cathode.

Quite a nicely engineered piece. Are the threads on the cap or screws metric-Teutonic?
Couldn’t you just leave the paper label in the photo and save me from all the guessing !:)

Looks very old school. If it wasnt for the threaded area I would have said it was from a military chest or cabinet, So if this was a quiz I would say it being brass aWW1 speaking tube cap or gun sight cover?

Hi Mr. Jeep,
Looks like a petrol fuel tank cap to me,(Brass). Maybe off a drop tank of some sorts, my guess is WW2. With an attaching wire that would be swaged into the “Crimp” bolted to cap, to stop cap getting lost,when re-fuelling. Although “Crimp” looks unused.?? But maybe that “Crimp” could be some earthing pin point, not sure there. Seem to remember that these caps screwed into filler neck and were then locked down by that lever/flap. But as flap isn’t connected to anything, guess it was used to twist cap “OFF” and “ON” Then pushed down flat for streamling. Some one else will be along to ID it pretty soon anyway. Just noticed, That operating flap looks steel to me though,(with corrosion ) so maybe this is an oil tank cap.

Bill T