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 14R. 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.
14R-04Improved 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-05RH rotation version of 14R-4.
14R-08RPM increased from 2,400 to 2,600 improving power output. LH rotation.
14R-09RH rotation version of 14R-08
14R-24LH rotation, 1,200 kW (1,600 hp).
14R-25RH rotation version of 14R-24.
14R-10014R-20028T-128 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.
Data from
Type: 14 cylinder two-row air-cooled radial piston engineBore: 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 m2 (14.3 sq ft)Valvetrain: Single inlet and exhaust valves operated by rockers and pushrodsSupercharger: Gear-driven 2-speed supercharger at 6.5:1 and 9.0:1 ratiosFuel system: 1x Bronzavia updraught carburettor with automatic boost and altitude controlFuel type: 92 Octane gasolineOil system: Pressure fed at 480 kPa (70 psi)Cooling system: Air-cooled with bafflesReduction gear: Planetary / epicyclic bevel reduction gearing at 0.67:1 ratioStarter: Air equipment electric inertia starterIgnition: 2 x R.B. magnetos, 2 x 18 mm (0.71 in) short reach spark plugs per cylinder fed by a shielded ignition harness.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 fuelMilitary, 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: 6.8:1Specific 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 
