Wright Whirlwind R-790-A (J-5) Radial 9 Engine

Object Details

Physical Description: Type: Reciprocating, 9 cylinders, radial, air-cooled; Power rating: 168 kW (225 hp) at 2,000 rpm; Displacement: 12.9 L (788 cu in.); Bore and Stroke: 114 mm ( 4.5 in.) x 140 mm ( 5.5 in.); Weight: 231 kg (508 lb)
Summary: The J-5 Whirlwind was a cornerstone aviation technology of the 1920s and 1930s. Charles L. Lawrance began work on the J-series of compact, lightweight, air-cooled radials for the U.S. Navy in 1921. The Navy merged Lawrance's firm with Wright Aeronautical in 1923 to further develop and manufacture the new engines. The J-5 had such advanced features as sodium-cooled exhaust valves and aluminum cylinder heads designed by engine pioneer Sam D. Heron.; The Whirlwind became the engine of choice for America's long-distance and exploratory fliers, including Charles Lindbergh, who chose a J-5 for the Spirit of St. Louis. This artifact, a military R-790-A, was the center engine on the Army Air Corps Fokker C-2 tri-motor “Question Mark,” which pioneered aerial refueling by setting an endurance record of 150 hours and 40 minutes over Los Angeles in 1929.

December 14, 1928

Materials: Aluminum, Steel, Paint, Phenolic, Rubber, Copper, Preservative coating
Dimensions: 3-D (Engine): 107.9 × 115.6 × 90.2cm (3 ft. 6 1/2 in. × 3 ft. 9 1/2 in. × 2 ft. 11 1/2 in.); 3-D (Overall with Stand): 113.3 × 132.1 × 147.3cm, 366.5kg (3 ft. 8 5/8 in. × 4 ft. 4 in. × 4 ft. 10 in., 808lb.); 3-D (Stand Base): 132.1 × 113.3 × 16.2cm (4 ft. 4 in. × 3 ft. 8 5/8 in. × 6 3/8 in.); 3-D (Prop Shaft Length): 24.4cm (9 5/8 in.)

National Air and Space Museum

GUID (Link to Original Record): http://n2t.net/ark:/65665/nv9a74ba979-2fae-49e2-a27f-3f0074f272ef