BSA “SPECIALS” for the Sporting Rider

01 Engine

luminium crankcases housed a single timing side roller main bearing with a ball and roller on the drive side. These supported a built up crank assembly with a roller big-end, the 88mm stroke was common to both engines. Barrels were iron, or alloy, with separate pushrod housings. Theseeventuallychanged to one-piece aluminium castings while a shorter con rod reduced the height of the engine. A 71mm piston for the B32 gave 348cc, that for the B34 was 85mm for 499cc. Inside the timing case and behind an out-rigger plate, separate camshafts