Very interesting piston valve V-twin steam engine designed for high speed running in a boat. The engine runs on ball races throughout, aluminium crankcase with bronze cylinders. Piston valve admission, exhaust by piston valve and auxiliary scavenge ports in the cylinder walls. This unit has been clocked at 18000rpm on flash steam, it now runs with a Scott 150 psi water tube gas-fired boiler. Boiler feed is by a variable stroke pump driven from the engine crankshaft - there is also an auxiliary hand pump.
The cocks on top of the cylinder heads are compression release valves, opened for starting then closed one after the other as the engine speed increases.
This unique engine won a bronze medal at the Wembley Model Engineer Exhibition in London.
Flywheel diameter 2 1/4 inches
Base 31 x 5 inches
