What is the difference between a Rotary and a Radial ?
A rotary engine is characterized by a fixed crankshaft and cylinders that rotate. The propeller is attached to the spinning crankcase. A fuel metering carburetor is attached to the hollow fixed crankshaft. Air, fuel and castor oil ( for lubrication ), are drawn into the crankcase then pass through the intake pipes to the cylinders. The exhaust is timed to exit at the bottom of the engine to minimize interference with the pilot. This arrangement was common in World War I, when modern high-strength, heat resistant, steels were not commonly available. Cooling was accomplished by having the cylinders spin. This is completely different from the Wankel Rotary car engine developed in the 1970s.
