The Pratt & Whitney R-985 Wasp Junior is a series of nine-cylinder, air-cooled, radial aircraft engines built by the Pratt & Whitney Aircraft Company from the 1930s to the 1950s.[1] These engines have a displacement of 985 in3 (16 l); initial versions produced 300 hp (220 kW), while the most widely used versions produce 450 hp (340 kW).