Wright R-1300 Cyclone 7
# Wright R-1300 Cyclone 7

The Wright R-1300 Cyclone 7 is an American air-cooled seven-cylinder supercharged radial aircraft engine produced by Curtiss-Wright.

## Design and development

The R-1300 is basically a single row Wright R-2600. The engine was mass-produced but not widely used. Engineering began in 1942 but the first flight of an R-1300 did not take place until 1949. The engine was produced under license by Kaiser-Frazer and later by AVCO Lycoming.

The engine was used in combat — the R-1300-1A and -1B in the A model North American T-28 Trojan and the R-1300-3, -3A, -3C and -3D in the Sikorsky H-19 Chickasaw. The R-1300-1B was used to power the Ayres Thrush. The R-1300-4 and -4A were used in the N class blimp; 50 of these variants were produced by AVCO.

Early-production engines had vibration problems, an improved lateral dampener in the crank brought about most of the model changes.

## Variants

### R-1300-2

    A direct drive version of the R-1300-1. It had a 0.5625:1 reduction drive. Both used the PD9F1 carburetor.

### R-1300-3

    Derated to 690.3 hp (515 kW), uses forced-air cooling fan and uses a PD9G1 carburetor.

### R-1300-4

    Similar to the R-1300-1, uses some different accessory components.

### R-1300-CB7A1

    With reduction gear for use on fixed wing aircraft.

## Applications

* Hispano HA-100
* N class blimp
* North American T-28 Trojan
* Rockwell Thrush Commander
* Sikorsky H-19
* Westland Whirlwind

## Specifications (R-1300-1A)

Data from Type Certificate Data Sheet 5E-14.

### General characteristics

* Type: 7-cylinder supercharged air-cooled single row radial engine
* Bore: 6.125 in (155.6 mm)
* Stroke: 6.312 in (160.3 mm)
* Displacement: 1,301 cu in (21.32 L)
* Length: 48.22 in (1,225 mm)
* Diameter: 55 in (1,397 mm)
* Dry weight: 1,055 lb (478 kg)

### Components

* Valvetrain: Two pushrod-actuated valves per cylinder with sodium-cooled exhaust valve
* Supercharger: 1-stage
* Fuel system: Bendix-Stromberg PD9F1 downdraft carburetor with automatic mixture control
* Cooling system: Air-cooled

### Performance

* Power output: 800 hp (596 kW)
* Specific power: 0.61 hp/in³ (27.94 kW/L)
* Compression ratio: 6.20:1
* Power-to-weight ratio: 0.76hp/lb (1.25 kW/kg)
