# SNECMA 14R

The SNECMA 14R was a 14-cylinder two-row air-cooled radial engine developed in France just prior to the start of World War II from the Gnome-Rhône 14N. The 14N radial engine was itself an improved version of the popular pre-war Gnome-Rhône 14K Mistral Major series; designed and manufactured by Gnome et Rhône, a major French aircraft engine manufacturer whose origins pre-date the First World War.
The improved 14R was initially known as the Gnome-Rhône 14P and then the Gnome-Rhône 14R. There were several improvements such as the introduction of a longer crankshaft and crankcase with a centre bearing, an increase in cylinder capacity, and a two-speed compressor. These changes allowed the engine to deliver 1,400hp at take-off and 1,300hp at 1,500m (1st gear) and 1200hp at 4000m (2nd gear). This came at the cost of a much increased total weight. It was expected that further development, such as the introduction of higher grade fuels, would lead to a power output of 1,660hp at low altitude.
With the Fall of France, engine development was stopped under the occupation. After the war, development recommenced; however production of this engine after 1945 was transferred to the newly formed SNECMA and the engine was renamed the SNECMA 14R.

## Variants
### 14R-04

    Improved higher performance using 92 Octane fuel. 14N with 2-speed supercharge (6.5:1 and 9:1), LH rotation, 1,190 kW (1,590 hp) for take-off.

### 14R-05

    RH rotation version of 14R-4.

### 14R-08

    RPM increased from 2,400 to 2,600 improving power output. LH rotation.

### 14R-09

    RH rotation version of 14R-08

### 14R-24

    LH rotation, 1,200 kW (1,600 hp).

### 14R-25

    RH rotation version of 14R-24.

### 14R-26

    LH rotation, 1,200 kW (1,600 hp).

### 14R-27

    RH rotation version of 14R-26.

### 14R-28

    LH rotation, 1,200 kW (1,600 hp).

### 14R-29

    RH rotation version of 14R-28.

### 14R-32

    LH rotation

### 14R-200

    LH rotation

### 14R-201

    RH rotation

### 28T-1

    28 cylinder, double 14R-24 engines placed back-to-back with co-axial contra-rotating propeller shafts, direct fuel injection, 2-speed supercharger, 77.4 L (4,720 cu in) displacement, delivering 2,400 kW (3,200 hp) for take-off using 100/130 octane fuel.

## Applications

* Sud-Est SE.200 Amphitrite
* SNCASE SE-1010
* Nord Noroit - only the prototypes had the Gnome-Rhône 14R
* Nord 1500 Noréclair
* Nord Noratlas - only the prototype had the Gnome-Rhône 14R
* SNCAC NC.211 Cormoran

## Specifications (14R-04)

Data from

### General characteristics

* Type: 14 cylinder two-row air-cooled radial piston engine
* Bore: 146 mm (5.75 in)
* Stroke: 165 mm (6.50 in)
* Displacement: 38.7 L (2,361.62 cu in)
* Length: 1,635 mm (64.37 in)
* Diameter: 1,297 mm (51.06 in)
* Dry weight: 819 kg (1,805.59 lb)
* Frontal Area: 1.33 m$^2$ (14.3 sq ft)

### Components

* Valvetrain: Single inlet and exhaust valves operated by rockers and pushrods
* Supercharger: Gear-driven 2-speed supercharger at 6.5:1 and 9.0:1 ratios
* Fuel system: 1x Bronzavia updraught carburettor with automatic boost and altitude control
* Fuel type: 92 Octane gasoline
* Oil system: Pressure fed at 480 kPa (70 psi)
* Cooling system: Air-cooled with baffles
* Reduction gear: Planetary / epicyclic bevel reduction gearing at 0.67:1 ratio
* Starter: Air equipment electric inertia starter
* Ignition: 2 x R.B. magnetos, 2 x 18 mm (0.71 in) short reach spark plugs per cylinder fed by a shielded ignition harness.

### Performance

* Power output:
* Take-off:1,590 hp (1,185.66 kW) at 2,600 rpm at 1,180 mm (46.46 in) Hg boost with 100 octane fuel
** Military, low:1,660 hp (1,237.86 kW) at 2,600 rpm at 1,000 m (3,280.84 ft)
** Military, high:1,580 hp (1,178.21 kW) at 2,600 rpm at 5,500 m (18,044.62 ft)
** Normal, low:1,320 hp (984.32 kW) at 2,400 rpm at 2,100 m (6,889.76 ft)
** Normal, high:1,230 hp (917.21 kW) at 2,400 rpm at 6,000 m (19,685.04 ft)
* Specific power: 31.85 kW/L (0.7 hp/cu.in)
* Compression ratio: 6.8:1
* Specific fuel consumption: 0.292 kg/kW/hr (0.48 lb/hp/hr)
* Oil consumption: 0.0067 kg/kW/hr (0.011 lb/hp/hr)
* Power-to-weight ratio: 1.494 kW/kg (0.909• hp/lb)
* B.M.E.P.: 1,470 kPa (213 psi)
* 14R-05 propeller rotates in opposite direction