[Capt. Quirk]

A lot could be learned from that old B&S L-Head configuration. Engine builders can get more horsepower with the 5hp upright engine than the newer OHV intec engines, fully modified uprights can exceed 45 horsepower.

With common microprocessors you could make your own ignition and fuel injection systems, changes to the engine like (mechanical) adjustable cam timing and or valve lift or even (microprocessor controlled) electronic valve solenoids and scrap the camshaft altogether. Also there is a large amount of aftermarket parts available.

Engine testing could be accomplished with a small, easy to build inertia dyno that could simulate the actual vehicle.