Wright R-1820 Cyclone Explained

The Wright R-1820 Cyclone 9 is an American radial engine developed by Curtiss-Wright, widely used on aircraft in the 1930s through 1950s. It was produced under license in France as the Hispano-Suiza 9V or Hispano-Wright 9V, and in the Soviet Union as the Shvetsov M-25.

Design and development

The R-1820 Cyclone 9 represented a further development of the Wright P-2 engine dating back to 1925. Featuring a greater displacement and a host of improvements, the R-1820 entered production in 1931. The engine remained in production well into the 1950s.

The R-1820 was built under license by Lycoming, Pratt & Whitney Canada, and also, during World War II, by the Studebaker Corporation. The Soviet Union had purchased a license for the design, and the Shvetsov OKB was formed to metricate the American specification powerplant for Soviet government-factory production as the M-25, with the R-1820's general design features used by the Shvetsov design bureau for many of their future radials for the Soviet air forces through the 1940s and onwards. In Spain the R-1820 was license-built as the Hispano-Suiza 9V or Hispano-Wright 9V.^[1]

The R-1820 was at the heart of many famous aircraft including early Douglas airliners (the prototype DC-1, the DC-2, the first civil versions of the DC-3, and the limited-production DC-5), every wartime example of the Boeing B-17 Flying Fortress and Douglas SBD Dauntless bombers, the early versions of the Polikarpov I-16 fighter (as the M-25), and the Piasecki H-21 helicopter.

The R-1820 also found limited use in armoured vehicles. The G-200 variant developed 900lk=onNaNlk=on at 2,300 rpm and powered the strictly experimental M6 Heavy Tank.

D-200 Diesel

The Wright R-1820 was converted to a diesel during World War II by Caterpillar Inc. as the D-200 and produced 450hp at 2,000 rpm in the M4A6 Sherman.

Variants

Notes: Unit numbers ending with W indicate engine variants fitted with water-methanol emergency power boost systems.

Hispano-Suiza 9V

The Hispano-Suiza 9V is a licence-built version of the R-1820.^[2]

Hispano-Suiza 9Vr:9V with reduction gear

Hispano-Suiza 9Vb:

Hispano-Suiza 9Vbr:variant of the 9Vb with reduction gear^[2]

Hispano-Suiza 9Vbrs:variant of the 9Vb with reduction gear and supercharger

Hispano-Suiza 9Vbs:variant of the 9Vb with supercharger^[2]

Hispano-Suiza 9Vd:variant of the 9V^[2]

Hispano-Suiza 9V-10:575abbr=onNaNabbr=on driving fixed-pitch propeller

Hispano-Suiza 9V-11:as -10 but RH rotation

Hispano-Suiza 9V-16:650abbr=onNaNabbr=on driving variable-pitch propeller, LH rotation

Hispano-Suiza 9V-17:as -16 but RH rotation

Applications

Vehicles

• M4A6 tank
• M6 heavy tank

Engines on display

Preserved Wright R-1820 engines are on display at the following museums:

• American Airlines C.R. Smith Museum^[3]
• Fleet Air Arm Museum
• Delta Flight Museum
• National Air and Space Museum
• National Museum of the U.S. Air Force

Bibliography

• Bridgman, L, (ed.) (1998) Jane's Fighting Aircraft of World War II. Crescent. .
• Web site: Conners . Chris . Medium Tank M4 Sherman . 2013 . 9 January 2014 . American Fighting Vehicle Database .
• Eden, Paul & Soph Moeng, The Complete Encyclopedia of World Aircraft. Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, .
• Gunston, Bill. World Encyclopedia of Aero Engines: From the Pioneers to the Present Day. 5th edition, Stroud, UK: Sutton, 2006.
• White, Graham. Allied Aircraft Piston Engines of World War II: History and Development of Frontline Aircraft Piston Engines Produced by Great Britain and the United States During World War II. Warrendale, Pennsylvania: SAE International, 1995.
• Book: Lage, Manual. Hispano Suiza in Aeronautics. 2004. SAE International. Warrendale, USA . 0-7680-0997-9.
• Web site: Aircraft Engines in Armored Vehicles . 2006-10-03 . dead . https://web.archive.org/web/20061007163521/http://www.enginehistory.org/featured_engines.htm . 2006-10-07.

Notes and References

1. Lage(2004) pp. 157-162
2. Book: Hartmann, Gustave. Hispano-Suiza, Les moteurs de tous les Records.pdf. fr.
3. News: May. Joseph. Flagship Knoxville — an American Airlines Douglas DC-3. 3 August 2014. Hearst Seattle Media. 8 January 2013.