High Quality Content by WIKIPEDIA articles! 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. These engines have a displacement of 985 cu in (16 L); initial versions produced 300 hp (220 kW), while the most widely used versions produce 450 hp (340 kW).