De Havilland Gipsy Six
The de Havilland Gipsy Six is a British six-cylinder, air-cooled, inverted inline piston engine developed by the de Havilland Engine Company for aircraft use in the 1930s. It was based on the cylinders of the four-cylinder Gipsy Major and was developed into a series of similar aero engines which were still in common use until the 1980s.