Gnome-Rhône 14M

The Gnome-Rhône 14M was a small 14-cylinder two-row air-cooled radial engine that was used on several French and German aircraft of World War II. While having the same appearance, number of pistons (14) and two-row layout typical of Gnome-Rhône radial engines, the 14M was built to a smaller frame intended to power a lighter class of aircraft. It was designed with lower displacement and power, smaller in size and with less weight compared to the larger, heavier Gnome-Rhône 14N and its well-known predecessor.

Gnome-Rhône 14M Mars
A preserved Gnome-Rhône 14M-05 Mars
Type	Radial engine
National origin	France
Manufacturer	Gnome et Rhône
First run	1936
Developed from	Gnome-Rhône 14N

Variants

14M-00

LH rotation, 474 kW (635 hp)

14M-01

RH rotation identical to 14M-00

14M-04

LH rotation, 521.99 kW (700 hp)

14M-05

RH rotation identical to 14M-04

14M-06

LH rotation, 521.99 kW (700 hp), reduction gear 0.71:1

14M-07

RH rotation identical to 14M-06

14M-08

LH rotation, 559.27 kW (750 hp), reduction gear 0.71:1

14M-09

RH rotation identical to 14M-08

Applications

• Breguet 693
• Bloch MB.700
• Gotha Go 244
• Henschel Hs 129B
• Focke-Wulf Fw 189E
• LWS-3 Mewa
• Lioré et Olivier LeO 20
• Morane-Saulnier Vanneau
• Potez 220
• Potez 630
• Potez 631
• Potez 633
• Potez 637
• Potez 63.11
• Potez 662
• Roussel R-30
• SNCAO CAO.600
• SNCASE SE-400
• SNCAC NC.510M
• SNCAC NC.530
• SNCAC NC.600

Specifications (14M-4)

(14M-5 identical except opposite rotation)

Data from

General characteristics

• Type: Fourteen-cylinder two-row supercharged air-cooled radial engine
• Bore: 122 mm (4.80 in)
• Stroke: 116 mm (4.57 in)
• Displacement: 18.92 L (1,154.6 cu in)
• Length: 1,251 mm (49.25 in)
• Diameter: 950 mm (37.40 in)
• Dry weight: 419 kg (924 lb)

Components

• Valvetrain: Two overhead valves per cylinder
• Supercharger: gear driven, 8.258:1 ratio, 1-speed supercharger
• Fuel system: Bronzavia 110-L2 carburetor with automatic boost and altitude control
• Fuel type: 87 octane rating gasoline
• Oil system: Pressure feed 482.6 kPa (70 psi), dry sump, 120 S.U. secs (25.1 cSt) grade oil.
• Cooling system: Air-cooled
• Reduction gear: 0.71:1
• Air Equipment 47 electric inertia starter

Performance

• Power output:
  
• (Take-off): 521.99 kW (700 hp) at 3,030 rpm for takeoff with 1,100 mm (43.3 in) Hg / +3 kg (6.6 lb) boost
• (Normal): 492.16 kW (660 hp) at 3,030 rpm at 4,000 m (13,123 ft)
• (cruising): 339.29 kW (455 hp) at 2,350 rpm at 4,000 m (13,123 ft)
• Specific power: 27.21 kW/L (0.61 hp/(cu in))
• Compression ratio: 6.5:1
• Specific fuel consumption: 0.29 kg/(kW h) (0.48 lb/(hp h))
• Oil consumption: 0.01 kg/(kW h) (0.018 lb/(hp h))
• Power-to-weight ratio: 1.27 kW/kg (0.77 hp/lb)
  • B.m.e.p. max: 1,075 kPa (155.9 psi)

See also

• Alvis Leonides
• Pratt & Whitney R-1535 a comparable engine sometimes fitted as an alternative to the 14M on French designs

References

• Danel, Raymond; Cuny, Jean. L'aviation française de bombardement et de renseignement 1918-1940 (Docavia n°12 ed.). France: Editions Larivière.
• Wilkinson, Paul H. (1946). Aircraft Engines of the World. London: Sir isaac Pitman & Sons Ltd.
• Tsygulev (1939). Aviacionnye motory voennykh vozdushnykh sil inostrannykh gosudarstv (Авиационные моторы военных воздушных сил иностранных государств) (in Russian). Moscow: Gosudarstvennoe voennoe izdatelstvo Narkomata Oborony Soyuza SSR. Archived from the original on 2009-03-24.