Concerning Flywheel Forum 51/4/6: Engine or Compressor? in the June/July 2016 issue, it’s hard to tell from just two photographs, but it appears that there is a radial engine coupled to what looks like a Bourke engine. Russell Bourke experimented with his engine in the 1920s and 1930s. It would be interesting to learn more of this engine, where it was found, etc. The Bourke engine is famous for its opposing pistons and Scotch yoke inside, which made a smooth running engine.
Magic Bill/via email
Thanks for the tip, Magic Bill. While it’s hard to verify from the photos sent in by Webb Marner, you might be on to something. Granted patent number 2,172,670 in 1939, the first Bourke engine was a 2-stroke flat twin. Both pistons traveled in the same direction at the same time, and it was designed to run without spark ignition once warm, effectively transitioning to a dieseling engine, yet burning gasoline. The 2-cylinder unit shown in Webb Marner’s photos has a crankcase-mounted carburetor, which lines up with a 2-stroke design.
The Bourke engine’s Scotch yoke, essentially a slotted link keyed to the connecting rod and the crankshaft to transfer the piston’s linear motion to rotational motion, made it possible to construct multi-cylinder rotary engines, suggesting the possibility that both engines in the photos are Bourke engines. However, it might simply be a flight of fancy, as Don Kuhl of Peebles, Ohio, thinks, who wrote in to say “it appears to me to be a fairly elaborate ‘do nothing’ machine.”
To see a neat animation of a Scotch yoke in action, check out the GIF below. – GEM
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