The Pratt & Whitney R-985 Wasp Junior was a raial engine widely used in American aircraft starting in the 1930s. It was a scaled-down version of the original R-1340, and the second in the Wasp family. It was a single-row, 9-cylinder air-cooled radial design. Displacement was 985 cubic inches (16.1 liters); bore and stroke were each 53⁄16 in (132 mm).