Pratt & Whitney Wasp A, R-1300 (R-1340), Radial 9 Engine

Type: Reciprocating, 9 cylinders, radial, air-cooled

Power rating: 317 kW (425 hp) at 1,900 rpm

Displacement: 22.2 L (1,344 cu in)

Bore and Stroke: 146 mm (5.8 in.) X 146 mm (5.8 in.)

Weight: 327 kg (720 lb)

Condition: Complete engine; grey crankcase and black cylinders; on display stand.

Having departed from Wright, Frederick Rentschler informed the Navy of his plan to manufacture air-cooled radial engines, and incorporated the Pratt & Whitney Aircraft Company on July 23, 1925. This Serial Number 1 Wasp, the first of a long series of famous aircraft engines from Pratt & Whitney, was completed on December 24, 1925 and finished the 50-hour approval test in March 1926. On May 5 a second Wasp took to the air in the Wright F3W-1 Apache aircraft. A contract for 200 Series A Wasps was received and production engines delivered before the end of 1926.

Known for its reliability, the new engine soon dominated U.S. fighter planes, and made commercial air transportation profitable in the Boeing 40A. The Boeing F2B-1 was the first operational aircraft to use the Wasp engine. Approximately 100 different experimental and production airplanes utilized the engine, with the Wasp R-1340 remaining in production until 1960.