Sunbeam Motorcycles 1930's

[Anonymous]

I was told by one of the technical advisors for the Sunbeam Register that "ALL THREADS ON YOUR SUNBEAM ARE 55 DEGREE WHITWORTH FORM CYCLE THREADS".

Hope this helps anyone that needs it. I have a 1929 Sunbeam motorcycle Model 8. I would love to hear from anyone that has any Sunbeams from 1928-38.

[Sunbeam1929]

I'm a member now!

[integerspin]

bit of an old thread.
I bought a Sunbeam Lion engine on ebay earlier this year. I decided the engine was probably 1931 or 1932. Don't know if these are thing to base it on but, enclosed valves, no oil pressure take off and riveted crank.
Some of the threads look like whit, as you would expect, but the cam cover threads are around 32tpi.
First thought was 2BA, didn't think it would be 3/16 BSF cos I read they made there own tooling up till the mid 30's and only used BSF after that, I did wonder about 3/16 BSCY?