This Cox .75 radial aircraft engine was designed and built by Paul Daniels, of Missouri, in the 1980s. The engine is 7″-long, 8″-wide, 9″-high, and weighs 7 lbs. 8 oz.
Mr. Daniels called his creation the “Cox .75” since it consists of five Cox .15 cubic-inch engines geared together inside his custom-machined housing. The gears are located behind the front cover and must be lubricated manually before running the engine. (Gears can be seen in the second photo.) In the back is a throttle-controlled carburetor that regulates the engine’s speed (revolutions per minute).