I HAVE AQUIRED A C15 BASKET CASE AND SORTING THROUGH THE BITS HAVE COME ACCROSS A NUMBER ON THE CRANK CASE, C15GP2370. IS THIS A PART NUMBER OR ENGINE NUMBER AND IF THE LATTER WHAT DOES GP DENOTE? SORRY IF THIS IS A DAFT QUESTION BUT I AM NEW TO BSA OWNERSHIP.
It is an engine number.
C15GP decodes G as the best and last and most robust of the C15 engines with improved main bearings and lubrication and the P indicates an engine fitted to a Police specification C15.
It would have been fitted to a frame with the same number.
The first C15G engines were produced in 1966.
Yours is a very late engine, they ended around 2400, and would be from 1967.
Cheers for that Julian. I'll check out the frame number. As I said, it came to me in bits.