Engine number

[buzzydog]

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.

[JulianS]

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.

[buzzydog]

Cheers for that Julian. I'll check out the frame number. As I said, it came to me in bits.