Ian, as already mentioned, there are no records of any C11's being officially supplied to the War Department other than the one contract for the India Office........that is not to say that some others were "impressed" for service use during 1939-40.........

The India Office C11's differ in that the engine is powered by a magdyno, rather than by the front-mounted distributor and coil ignition.....it would be hugely interesting to see an original example to establish exactly what modifications BSA made to the crank and timing cases....were they new castings or simply modified standard components......?

It's also interesting to note that the India Office contract has Frame numbers beginning with "WC11".......in many instances frames for the C10, C11 and C12 were usually just marked "C10" with the engine number reflecting the exact powerplant fitted..........

If you want a real rarity, find a WC12.......350cc SV supplied in tiny numbers to the Admiralty............post-war the C12 designation was used for a 250cc OHV but the original model was an enlarged C10........

Steve I have copies of all the ledgers that cover the 1939 and 1940 C models and although the handbook quotes the frame numbers prefixed with C11 they are in fact all prefixed C10. I've also calculated that 35 C12's were issued to the Admiralty which is now listed in your latest edition.

The WD C11 crankcase was obviously either modified or re-cast to accept the magdyno. The Timing case was also redesigned to accept the mag pinion which is about twice the size of the original dynamo sprocket. The timing case was then more oval instead of the usual pear shape.

The carb was one of Amal's sideways models.

I have been on the trail of a maydyno C11 engine for about 3 years now (Must be one of the India Office contract unless it's a home-brew?) .....But so far all my leads have ended up a dead end. Ron

email (option): ronpier@talk21.com