The 14N was a 14-cylinder two-row air-cooled radial engine designed and manufactured by Gnome-Rhône. A development of the pre-war Gnome-Rhône 14K, the 14N was used on several French and German aircraft of World War II.
Design and development
Facing criticisms over the 14K's reliability, Gnome-Rhône undertook a major upgrade of its 14-cylinder design, using different materials for the pistons and valves, and enlarging cooling surfaces by 39%.
The new 14N was introduced in 1937 and was quickly adopted on several aircraft models. In 1939, minor improvements allowed Gnome-Rhône to increase the compression ratio from 6.1:1 to 6.8:1, which resulted in increased power for wartime production aircraft.
The 14N was further developed into the Gnome-Rhône 14R featuring a 2-stage supercharger, but this type was not widely used until after World War II as production of improved engines was prohibited by the terms of the armistice with Germany.
Postwar the 14R was developed into a 28 cylinder high capacity engine as the Gnome-Rhône 28T-1, essentially two 14R-24 engines back to back driving co-axial contra-rotating propeller shafts.
Data from:Aircraft engines of the World 1945, Aircraft engines of the World 1946
14N-44LH rotation, 780 kW (1,050 hp).
14N-45RH rotation version of -44.
14N-48LH rotation, 880 kW (1,180 hp).
14N-49RH rotation version of -48.
14N-50LH rotation, 1,000 kW (1,400 hp).
14N-54LH rotation, 930 kW (1,250 hp).
14N-55RH rotation version of -54.
14N-58LH rotation, 880 kW (1,180 hp).
14N-59RH rotation version of -58.
14R-4Improved 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-5RH rotation version of 14R-4.
14R-24LH rotation, 1,200 kW (1,600 hp).
14R-25RH rotation version of 14R-24.
28T-128 cylinder, double 14R-24 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.
Amiot 351Amiot 354Bloch MB.131Bloch MB.151Bloch MB.152Bloch MB.155Bloch 174Bloch 175Bloch MB.210Breguet 891R Mars (2 × 14R)Farman F.222Latécoère 611Lioré et Olivier LeO 45Sud-Est SE.161 LanguedocMesserschmitt Me 323Koolhoven F.K.58PZL P.24PZL.43 KaraśSNCAO CAO.700 (2X 14N-48 + 2x 14N-49)Data from Aircraft engines of the World 1945
Type: Fourteen-cylinder two-row air-cooled piston engineBore: 146 mm (5.75 in)Stroke: 165 mm (6.50 in)Displacement: 38.67 l (2,360 cu in)Length: 1,480 mm (58.27 in)Diameter: 1,290 mm (50.79 in)Dry weight: 620 kg (1,370 lb)Valvetrain: Two inlet and two exhaust overhead valves per cylinderSupercharger: Single-stage single-speed centrifugal type superchargerFuel system: Stromberg carburetorFuel type: 87 octane rating gasolineOil system: Pressure fed at 480 kPa (70 psi)Cooling system: Air-cooledReduction gear: 0.5:1 planetary reduction gearingPower output:
Take-off: 880 kW (1,180 hp) at 2,650 rpmMilitary: 790 kW (1,060 hp) at 2,400 rpm at 3,900 m (12,800 ft)Cruise: 630 kW (850 hp) at 2,100 rpm at 3,900 m (12,800 ft)Specific power: 22.45 kW/l (0.49 hp/in³)Compression ratio: 6.8:1Power-to-weight ratio: 1.4 kW/kg (0.85 hp/lb)
