Wright Whirlwind R-790-A (J-5) Radial 9 Engine
date: label: Date
content: December 14, 1928
name: label: Manufacturer
content: Wright Aeronautical
notes: label: Physical Description
content: Type: Reciprocating, 9 cylinders, radial, air-cooled
label: Physical Description
content: Power rating: 168 kW (225 hp) at 2,000 rpm
label: Physical Description
content: Displacement: 12.9 L (788 cu in.)
label: Physical Description
content: Bore and Stroke: 114 mm ( 4.5 in.) x 140 mm ( 5.5 in.)
label: Physical Description
content: Weight: 231 kg (508 lb)
label: Summary
content: 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.
label: Summary
content: 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.
place: label: Country of Origin
content: United States of America
setName: label: See more items in
content: National Air and Space Museum Collection
label: Location
content: National Air and Space Museum in Washington, DC
label: Exhibition
content: Barron Hilton Pioneers of Flight
creditLine: label: Credit Line
content: Transferred from the War Department, Air Corps
dataSource: label: Data Source
content: National Air and Space Museum
identifier: label: Inventory Number
content: A19290017000
objectType: label: Type
content: PROPULSION-Reciprocating & Rotary
objectRights: label: Restrictions & Rights
content: CC0
physicalDescription: label: Materials
content: Aluminum, Steel, Paint, Phenolic, Rubber, Copper, Preservative coating
label: Dimensions
content: 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.)
label: Dimensions
content: 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.)
label: Dimensions
content: 3-D (Stand Base): 132.1 × 113.3 × 16.2cm (4 ft. 4 in. × 3 ft. 8 5/8 in. × 6 3/8 in.)
label: Dimensions
content: 3-D (Prop Shaft Length): 24.4cm (9 5/8 in.)