The In-Line Air-Cooled Engine

QUOTING a comparison of the radial engine with a star fish, the author compares the frontal areas of radial and V-type engines and shows how air can be applied to the cylinders of in-line engines to secure efficient cooling with minimum parasite drag.

Advantages of upright and inverted engines are contrasted in various respects; and engine-mountings, cylinder design and valve gears are discussed.

Difficulties that have been encountered in gearing in-line engines having less than 12 cylinders are mentioned, and a simple method of gearing is proposed in which the elasticity of a relatively long propellershaft is utilized.

The paper concludes with a comparison of the production problems of radial and in-line aircraft engines.