The Pratt & Whitney R-1340 Wasp was a reciprocating engine widely used in American aircraft from the 1920s onward. It was the company's first engine, and the first of the famed Wasp family.[1] It was a single-row, 9-cylinder air-cooled radial design, and displaced 1,344 cubic inches (22 liters); bore and stroke were both 5.75 inches.