The Pratt & Whitney R-1340 Wasp was an aircraft engine of the reciprocating type that was widely used in American aircraft from the 1920s onward. It was the Pratt & Whitney aircraft company's first engine, and the first of the famed Wasp series .  It was a single-row, nine- cylinder , air-cooled , radial design, and displaced 1,344 cubic inches (22 L); bore and stroke were both 5.75 in (146 mm). A total of 34,966 engines were produced. 
Completed on Christmas Eve of 1925, the Wasp was an air-cooled, radial piston engine with 1,340 cubic inches of displacement. It also featured a revolutionary design for the crankshaft and master rod, which eliminated what had proved to be a weak area in other engines. The new Wasp weighed less than 650 pounds.