Wright R-1820

Wright R-1820
Name	Wright R-1820
Type	9-cylinder radial aircraft engine
First run	1927
Designer	Wright Aeronautical
Manufacturer	Wright Aeronautical, Curtiss-Wright
Produced	1927–1955
Bore	5+1/2 in
Stroke	6+1/2 in
Displacement	1,820 cu in
Power	700–1,350 hp (typical variants)
Compression	5.3:1 to 7.0:1

Wright R-1820 The Wright R-1820 is a single-row, nine-cylinder radial aircraft engine developed in the late 1920s by Wright Aeronautical and later produced by Curtiss-Wright. Renowned for its displacement of 1,820 cubic inches and robust power band, it powered a wide range of aircraft on both civil and military programs from the interwar period through World War II. The engine's longevity derived from iterative improvements, licensing, and widespread adoption by manufacturers and operators worldwide.

Design and development

Wright Aeronautical began development in the context of post-World War I aviation expansion, building on experience from designers associated with Glenn Curtiss, Charles Lindbergh era demands, and requirements from Boeing and Douglas Aircraft Company. Early prototypes responded to requests from United States Army Air Corps and United States Navy procurement officers seeking reliable powerplants for bombers such as proposals from Martin and Northrop. Engineering work integrated lessons from contemporaries at Pratt & Whitney and Rolls-Royce, with metallurgy input influenced by firms like General Electric and research at National Advisory Committee for Aeronautics laboratories. The R-1820 used forged crankcases, steel crankshafts, and improved carburetion designed with feedback from operators including Pan American World Airways and United Airlines. Certification trials involved testing under oversight from Civil Aeronautics Authority inspectors and were evaluated against standards promoted by Aviation Manufacturing Association committees.

Variants and submodels

The R-1820 family expanded into numerous submodels to meet diverse needs of manufacturers such as Lockheed, Consolidated Aircraft, Grumman, and Curtiss-Wright. Early commercial versions competed with Wright R-975 and evolved into military ratings designated by Army Air Corps procurement codes. Notable iterations included fuel-injected variants adopted by B-17 Flying Fortress designers and high-compression models used in B-24 Liberator development. Specialized variants were modified for naval use aboard aircraft carriers and for export to nations such as United Kingdom, France, Soviet Union, China, and Brazil. Experimental turbocharged and supercharged submodels used hardware from suppliers like Bendix and Hamilton Standard to achieve high-altitude performance for reconnaissance platforms associated with Lockheed Vega derivatives and Douglas DC-3 conversions.

Operational history

The R-1820 entered service in commercial routes operated by Pan American World Airways and military squadrons assigned to United States Army Air Forces during World War II. It powered reconnaissance and patrol aircraft serving in theaters from the Pacific Ocean to the European Theater of Operations, supporting campaigns that included logistics for Operation Torch and airlift during Battle of the Bulge operations. Operators included national air arms of United Kingdom, Free French Forces, Royal Australian Air Force, Royal Canadian Air Force, and Soviet Air Force. Postwar, R-1820s remained in service with civilian operators such as TWA and preservation fleets at museums like the Smithsonian Institution and National Air and Space Museum. The engine's reliability made it a mainstay for record attempts tied to aviators like Jimmie Mattern and corporate demonstration teams affiliated with Lockheed and Douglas.

Applications (aircraft and uses)

R-1820 variants were installed in models produced by manufacturers including Boeing (prototype transports), Consolidated Aircraft (notably the B-24 Liberator), Douglas (selected transports), Lockheed (high-speed transports and racers), Grumman (naval fighters and bombers), Vultee (attack aircraft), Curtiss (reconnaissance), Martin (medium bombers), Noorduyn (utility aircraft), and Sikorsky (some amphibious conversions). Civil uses encompassed mailplanes, executive transports, survey aircraft operated by Aero Service Corporation, and cargo services run by Eastern Air Lines and Varig. Military roles spanned patrol, bomber, transport, and trainer applications for forces including USAAF, USNavy, RAF, RAAF, and export customers such as Chinese Nationalist Air Force and Peruvian Air Force.

Technical specifications

General characteristics: - Configuration: single-row, 9-cylinder radial - Displacement: 1,820 cu in (29.8 L) - Bore × stroke: 5.5 in × 6.5 in - Typical power range: 700–1,350 hp depending on model and boost settings - Compression ratios varied across models to meet altitude performance standards of Army Air Corps and Naval Air Systems Command specifications Key components included carburetors and superchargers manufactured to tolerances influenced by Society of Automotive Engineers standards, with ignition systems incorporating magnetos from suppliers like Bendix and accessory drives compatible with propellers from Hamilton Standard and Curtiss Propeller Company. Cooling was air-based with finned cylinders treated via processes developed with metallurgical support from U.S. Steel and testing at Langley Research Center.

Production and manufacturers

Initial production was undertaken by Wright Aeronautical; following corporate consolidation, mass production shifted to Curtiss-Wright factories and licensed manufacturers in allied countries including facilities operated by Savoia-Marchetti partners and workshops in Canada under contracts with Victory Aircraft. Major subcontractors included Pratt & Whitney Machine Tools for tooling, General Motors divisions for component casting, and Allison workshops for accessory units. Wartime production involved coordination with War Production Board planning and workforce training programs influenced by National War Labor Board policies. After World War II, surplus engines supported civilian remanufacture programs run by companies such as Standard Aero and restoration groups affiliated with Experimental Aircraft Association.

Category:Aircraft engines