How the radial aircraft engine works.

In the early days, automobile engines were modified for use in flying machines. The designs are:Inline, as in most car engines today – and in older aircraft engines (think DH Gipsy Major); Vee engines, such as pioneered by the Ford V-8 – and the Rolls-Royce Merlin; and Horizontally-opposed auto engines, think Porsche – and the modern Continental aero engines. Radial engines were not used in automobiles, although there were land and marine applications.

The radial engine is a reciprocating type, internal combustion engine configuration in which the cylinders ‘radiate’ outward from a central crankcase like the spokes of a wheel. The radial configuration was very commonly used for aircraft engines before turbine engines became predominant. For an excellent visual presentation, see:

Part 1 youtu.be/qjnQKXNPsk4