Scale-Model Engines Designed by Dick Upshur

Scale progression

Air Cooled Engine
An offspring of the engine in Photo #4. It's an opposed two-cylinder, and the similarities are quite evident. It was designed in 2000, and a number of these have been completed and run by other builders. Fabricated construction again is in steel and aluminum, although I have seen one in brass already. The breaker points operate at crankshaft speed, and a simple distributor is driven at camshaft speed. The low-mounted throttling carburetor works well, and again an air filter was added for dusty meets. The major problem with this design has been too much oil churning around in the case and blowing out the exhaust pipes. I have found the oil level is somewhat critical and have added a dipstick to monitor it. The bore on this engine is also 3/4-inch and stroke 0.72-inch.
Photo by Dick Upshur