My Empire star -36 engine have a C stamped at the crankcase.
The engine number to the left of the raised BSA letters, and the C to the right.
Does anyone know what the C is for?
I asked my Friend Leon who has collected every model from the 1936 model year. He writes:-
I can't find conclusive evidence but I have seen it before. Plese note that the Empire Star was supplied with 2 pistons: 1 high compression and a low compression. Typically in the Q8 the low compression was fitted. My theory is that the C denotes the low compression piston and HC the high compression piston.
Kind regards,
Leon
That sounds like a reasonable explanation.
Thank you, and thank you to your friend Leon.
By the way, do you have any idea of the original compression ratios, and what could be a good alternative for daily riding with modern fuel in the tank?
I don't know the answer. This is from Leon's website:-
R5 Empire Star or 3.48 h.p. O.H.V. Empire Star. The top of the line sporting 348cc OHV Empire Star model was introduced for the Silver Jubilee of King George V. It has the same specification as the New Blue Star with all the extra bits like high compression piston, special cams, upswept exhaust pipes, foot change and AMAL Pump carburettor. Low compression piston supplied as spare. black frame, chrome plated petrol tank with Empire Star green panels, instrument panel in tank, chrome plated rims with green centres. Two upswept exhaust pipes, foot change gearbox, high compression piston, special cams and AMAL pump carburettor. Quickly detachable rear wheel.
Website here...https://www.bsa1930s.nl/
Ron
Thank you Ron :-)
It is a 500 but very much the same as the 350
I think he calls that the Q8, later to become the Gold Star. I've just had 16 front pipes made and chromed for Leon then 16 silencers to his drawing made and chromed at Armours. Ron