The rotary radial engine is a special construction form of the radial engine. The case rotates also or together with the cylinders. The crankshaft can turn in the same direction or in counter direction. The fuel reaches the cylinder in some cases through the crankshaft and a check valve in the piston crown. With a maximum performance of approx. 147 kW (200 HP) at the end of the First World War the development of this engine ceased.
In the airplane the propeller rotates together with the complete casing. Large mass forces develop and complicate the handling of the airplane. An advantage of this engine, in line with the radial engine is its low weight and the even more efficient cooling. The motorcycle Megola on top in the figure has a low centre of gravity, but it is front-heavy and therefore difficult to steer. Also the consumption of fuel and lubricating oil is higher. A mixture formation through the warm crankshaft is not really optimal. 01/08