The Cygnet Royal
There can be no doubt that Edgar Westbury (1896-1970) was a true, but unassuming, giant of the model engineering fraternity. Designing and building over 60 unique IC and steam engines, one wonders how he also found time to edit bi-weekly issues of the Model Engineer magazine for almost 20 years!
Westbury's Cygnet Royal, a 3 cylinder radial steam engine was conceived in 1962 as an experimental crossover between steam and IC build techniques. It was designed as a marine engine for use behind a flash steam generator, withstanding high pressure (80psi and upwards) and running at high speed (typically 3,000rpm +). In many ways, with its in-line orbital distribution valve, it behaves as a 2 stroke IC engine but running much more smoothly. The single throw crankshaft runs on ball bearings within an oil filled crankcase.
As well as being a elegant curiosity, the Cygnet Royal is a good deal lighter and more compact than conventional steam engines of a similar output. Measuring around 4" x 4" x 4", the engine has a bore x stroke of Ø5/8" x ½". Having 3 cylinders, the Cygnet Royal is also a self-starting engine - just add steam (or compressed air) and off it goes!
The Cygnet Royal in Action