# Wright R-1820 Cyclone

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.
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 armored 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.

## 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.

#### Hispano-Suiza 9Vr

    9V with reduction gear

#### Hispano-Suiza 9Vbr

    variant of the 9Vb with reduction gear

#### Hispano-Suiza 9Vbrs

    variant of the 9Vb with reduction gear and supercharger

#### Hispano-Suiza 9Vbs

    variant of the 9Vb with supercharger

#### Hispano-Suiza 9Vd

    variant of the 9V

#### 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

* Bloch MB.221
* Boeing B-17 Flying Fortress
* Boeing 307 Stratoliner
* Brewster F2A Buffalo
* Curtiss AT-32-A Condor
* Curtiss SBC-4 Helldiver
* Curtiss P-36 Mohawk
* Curtiss SC Seahawk
* Curtiss-Wright CW-21
* Douglas A-33
* Douglas B-18 Bolo
* Douglas DC-2
* Douglas DC-3 (DST, G-102 and G-202)
* Douglas R4D-8/C-117D
* Douglas DC-5
* Douglas DF Wright SGR-1820G-2
* Douglas SBD Dauntless
* FMA AeMB.2 Bombi
* General Motors FM-2 Wildcat
* Grumman TF-1 / C-1 Trader
* Grumman E-1 Tracer
* Grumman FF
* Grumman F3F
* Grumman XF5F Skyrocket
* Grumman XP-50
* Grumman HU-16 Albatross
* Grumman J2F Duck
* Grumman S-2 Tracker
* Lockheed Model 14 Super Electra
* Lockheed Model 18 Lodestar
* Lockheed Hudson
* Martin B-10
* North American A-27
* North American O-47
* North American P-64
* North American T-28B/C/D Trojan
* Northrop N-3PB
* Northrop YC-125 Raider
* Piasecki H-21
* Polikarpov I-16
* PZL.44 Wicher
* Ryan FR Fireball
* Sikorsky S-58/HUS/HSS/H-34
* Vultee V-1

### 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
* Fleet Air Arm Museum
* Delta Flight Museum
* National Air and Space Museum
* National Museum of the U.S. Air Force
* Wings of Freedom Aviation Museum
* 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.

### 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)