Careful searching turned up a Hepolite piston that gave an initial compression ratio that measured out at 16:1, but which was reduced to 13.9:1 in order to give the bottom end a slightly easier time of it,and to improve flame-travel.
Squish, piston-to-valve,and plug-to-piston clearances were all carefully checked and modified where necessary to take account of the level of flexure estimated to be likely in the crank assembly under arduous usage.
Carburation is by a 600 series Amal Concentric specifically modified for alcohol use,and ignition by a Boyer Micro-Digital system.
The machine fired up with no hesitation once the engine and systems were installed by the customer, sounding absolutely superbly crisp , highly responsive, and marvellously crackly. That'll frighten the seagulls....
