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.
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.
Breguet 891R Mars (2 × 14R)
Lioré et Olivier LeO 45
Sud-Est SE.161 Languedoc
Messerschmitt Me 323
Type: Fourteen-cylinder two-row air-cooled piston engine
Bore: 146 mm (5.74 in)
Stroke: 165 mm (6.49 in)
Displacement: 38.67 L (2,360 in³)
Length: 1.48 m (66 in)
Diameter: 1.29 m (50.8 in)
Height: 1,289 mm (50.75 in)
Dry weight: 620 kg (1,370 lb)
Valvetrain: Two inlet and two exhaust overhead valves per cylinder
Supercharger: Single-stage single-speed centrifugal type supercharger
Fuel system: Stromberg carburetor
Fuel type: 87 octane rating gasoline
Cooling system: Air-cooled
868 kW (1,164 hp) at 2,650 rpm for takeoff
728 kW (976 hp) at 2,400 rpm at sea level
780 kW (1,045 hp) at 2,400 rpm at 4,800 m (15,750 ft)
Specific power: 22.45 kW/l (0.49 hp/in³)
Compression ratio: 6.8:1
Power-to-weight ratio: 1.4 kW/kg (0.85 hp/lb)