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