Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Interesting - I may be going mad, but it appears to be a two stroke with valves operated by eccentrics on the crankshaft. I can't quite get my head around it, but I see no reduction drive for a traditional cam system, so the valves appear at least to me, to be operating at crankshaft speed. I really have no confidence that I understand it correctly and am probably being laughed at by those that have actually worked it out.