With 16 cars and 12 motorcycles, all air-cooled, this simple means of internal combustion finds the spotlight.

Air-cooling is achieved by the fins around the engine. Cooling fins should be unobstructed and clean – heavy deposits of road dirt will reduce their efficiency. Allow the engine to cool then ...

For aircraft, which can travel at hundreds of miles per hour, engineers could place more fins on the engine and locate them closer together to increase cooling. The force of air was great enough ...