Hi Brian, Spoke to my pal, (you know who!) The Prototype Brum had a FY short stroke engine fitted at the time he bought it. The Ariel man wanted a crank for his Brum,a DPY long stroke ,as normally fitted to a Brum. An interesting thing was the engine in the Prototype was fitted with a “Hemmings” 9 stud head,and (I assume) a 9 stud barrel to suit. Does this make more sense? Geoff.
