Wright R-1820 Cyclone

R-1820 Cyclone
	Curtiss-Wright R-1820 Cyclone Radial Engine
Type	Radial engine
National origin	United States
Manufacturer	Wright Aeronautical
First run	1930s
Major applications	Boeing B-17 Flying Fortress ; Curtiss P-36 Hawk ; Douglas B-18 Bolo ; Douglas DC-3 ; Douglas SBD Dauntless ; General Motors FM-2 Wildcat ; Sikorsky H-34 ; North American T-28 Trojan
Number built	47,475
Variants	Shvetsov M-25
Developed into	Wright R-2600 ; Wright R-3350

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.^[2]

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 900 hp (670 kW) 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 450 hp (340 kW) at 2,000 rpm in the M4A6 Sherman.^[3]

Variants

R-1820-04: 700 hp (520 kW)
R-1820-1: 575 hp (429 kW)
R-1820-4: 770 hp (570 kW)
R-1820-19: 675 hp (503 kW)
R-1820-21: 690 hp (510 kW)
R-1820-22: 950 hp (710 kW)
R-1820-25: 675 hp (503 kW), 750 hp (560 kW), 775 hp (578 kW)
R-1820-32: 1,000 hp (750 kW)
XR-1820-32: 800 hp (600 kW)
R-1820-33: 775 hp (578 kW)
R-1820-34: 940 hp (700 kW), 950 hp (710 kW)
R-1820-34A: 1,200 hp (890 kW)
R-1820-40/42: 1,100 hp (820 kW), 1,200 hp (890 kW)
R-1820-41: 850 hp (630 kW)
R-1820-45: 800 hp (600 kW), 930 hp (690 kW)
R-1820-49: 975 hp (727 kW)
R-1820-50: 850 hp (630 kW)
R-1820-52: 1,000 hp (750 kW)
R-1820-53: 930 hp (690 kW), 1,000 hp (750 kW)
R-1820-56: 1,200 hp (890 kW), 1,350 hp (1,010 kW)
R-1820-57: 1,060 hp (790 kW)
R-1820-60: 1,200 hp (890 kW)
R-1820-62: 1,350 hp (1,010 kW)
R-1820-66: 1,200 hp (895 kW), 1,350 hp (1,007 kW)
R-1820-67/69: 1,200 hp (890 kW), fitted with turbosupercharger
R-1820-72W: 1,350 hp (1,010 kW), 1,425 hp (1,063 kW)
R-1820-74W: 1,500 hp (1,100 kW)
R-1820-76A,B,C,D: 1,425 hp (1,063 kW)
R-1820-77: 1,200 hp (890 kW)
R-1820-78: 700 hp (522 kW), 1,100 hp (820 kW)
R-1820-80: 700 hp (520 kW), 1,535 hp (1,145 kW)
R-1820-82WA: 1,525 hp (1,137 kW)
R-1820-84: 1,525 hp (1,137 kW)
R-1820-86: 1,425 hp (1,063 kW)
R-1820-97: 1,200 hp (890 kW), fitted with turbosupercharger
R-1820-103: 1,425 hp (1,063 kW)
SGR-1820-F3: 710 hp (530 kW), 720 hp (540 kW)
SGR-1820-F2: 720 hp (540 kW)
R-1820-F53: 770 hp (570 kW)
R-1820-F56: 790 hp (590 kW)
GR-1820-G2: 1,000 hp (750 kW)
R-1820-G3: 840 hp (630 kW)
R-1820-G5: 950 hp (710 kW)
R-1820-G101: 1,100 hp (820 kW)
R-1820-G102: 775 hp (578 kW)
GR-1820-G102A: 1,100 hp (820 kW)
R-1820-G102A: 1,100 hp (820 kW)
R-1820-G102A: 1,100 hp (820 kW)
R-1820-G202A: 1,200 hp (890 kW)
R-1820-G103: 1,000 hp (750 kW)
R-1820-G105: 1,000 hp (750 kW)
R-1820-G205A: 1,200 hp (890 kW)

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.^[4]

Hispano-Suiza 9Vr: 9V with reduction gear
Hispano-Suiza 9Vb
Hispano-Suiza 9Vbr: variant of the 9Vb with reduction gear^[4]
Hispano-Suiza 9Vbrs: variant of the 9Vb with reduction gear and supercharger
Hispano-Suiza 9Vbs: variant of the 9Vb with supercharger^[4]
Hispano-Suiza 9Vd: variant of the 9V^[4]
Hispano-Suiza 9V-10: 429 kW (575 hp) driving fixed-pitch propeller
Hispano-Suiza 9V-11: as -10 but RH rotation
Hispano-Suiza 9V-16: 480 kW (650 hp) driving variable-pitch propeller, LH rotation
Hispano-Suiza 9V-17: as -16 but RH rotation

Applications

Vehicles

Engines on display

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

Wright R-1820 Cyclone 9 engine of restored Douglas DC-3 "Flagship Knoxville" at American Airlines C.R. Smith Museum
Wright R-1820 cutaway at the Museum of Aviation
Wright R-1820 at the Museum of Aviation
Wright R-1820-82 Cyclone Radial Engine at Wings of Freedom Aviation Museum, Horsham, Pennsylvania

Specifications (GR-1820-G2)

Data from Jane's. ^[7]

General characteristics

Type: Nine-cylinder single-row supercharged air-cooled radial engine
Bore: 6.125 in (155.6 mm)
Stroke: 6.875 in (174.6 mm)
Displacement: 1,823 cu in (29.87 L)
Length: 47.76 in (1,213 mm)
Diameter: 54.25 in (1,378 mm)
Dry weight: 1,184 lb (537 kg)

Components

Valvetrain: Two overhead valves per cylinder with sodium-filled exhaust valve
Supercharger: Single-speed General Electric centrifugal type supercharger, blower ratio 7.134:1
Fuel system: Stromberg PD12K10 downdraft carburetor with automatic mixture control
Fuel type: 87 octane rating gasoline
Oil system: Dry sump with one pressure and one scavenging pump
Cooling system: Air-cooled

Performance

Power output: 1,000 hp (746 kW) at 2,200 rpm for takeoff
Specific power: 0.46 hp/in³ (20.88 kW/L)
Compression ratio: 6.45:1
Specific fuel consumption: 0.6 lb/(hp•h) (362 g/(kW•h))
Oil consumption: 0.35-0.39 oz/(hp•h) (13-15 g/(kW•h))
Power-to-weight ratio: 0.84 hp/lb (1.39 kW/kg)

References

^ "SUMMARY OF WRIGHT ENGINE SHIPMENTS 1920 – 1930" (PDF). Archived from the original (PDF) on 2021-10-10. Retrieved 2023-09-18.
^ Lage(2004) pp. 157-162
^ Conners 2013.
^ ^a ^b ^c ^d Hartmann, Gustave. Hispano-Suiza, Les moteurs de tous les Records.pdf (in French).
^ May, Joseph (8 January 2013). "Flagship Knoxville — an American Airlines Douglas DC-3". Hearst Seattle Media. Archived from the original on 10 October 2017. Retrieved 3 August 2014.
^ "Exhibit & Collection". Wings of Freedom. Retrieved 2024-09-06.
^ Bridgman 1998, p. 314.

Bibliography

Bridgman, L, (ed.) (1998) Jane's Fighting Aircraft of World War II. Crescent. ISBN 0-517-67964-7.
Conners, Chris (2013). "Medium Tank M4 Sherman". American Fighting Vehicle Database. Retrieved 9 January 2014.
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, ISBN 0-7607-3432-1.
Gunston, Bill. World Encyclopedia of Aero Engines: From the Pioneers to the Present Day. 5th edition, Stroud, UK: Sutton, 2006.ISBN 0-7509-4479-X
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. ISBN 1-56091-655-9
Lage, Manual (2004). Hispano Suiza in Aeronautics. Warrendale, USA: SAE International. ISBN 0-7680-0997-9.
"Aircraft Engines in Armored Vehicles". Archived from the original on 2006-10-07. Retrieved 2006-10-03.

[1] "SUMMARY OF WRIGHT ENGINE SHIPMENTS 1920 – 1930" (PDF). Archived from the original (PDF) on 2021-10-10. Retrieved 2023-09-18.

[2] Lage(2004) pp. 157-162

[FOOTNOTEConners2013-3] Conners 2013.

[Hartmann_Hispano-4] Hartmann, Gustave. Hispano-Suiza, Les moteurs de tous les Records.pdf (in French).

[5] May, Joseph (8 January 2013). "Flagship Knoxville — an American Airlines Douglas DC-3". Hearst Seattle Media. Archived from the original on 10 October 2017. Retrieved 3 August 2014.

[6] "Exhibit & Collection". Wings of Freedom. Retrieved 2024-09-06.

[7] Bridgman 1998, p. 314.

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