The Info List - Gnome-Rhône Mistral Major

The Gnome-Rhône
14K Mistral Major was a 14-cylinder, two-row, air-cooled radial engine. It was Gnome-Rhône's major aircraft engine prior to World War II, and matured into a highly sought-after design that would see licensed production throughout Europe
and Japan. Thousands of Mistral Major engines were produced, used on a wide variety of aircraft.


1 Design and development 2 Variants 3 Applications

3.1 Aircraft powered by G-R 14K derivatives

4 Specifications ( Gnome-Rhône

4.1 General characteristics 4.2 Components 4.3 Performance

5 See also 6 References

Design and development[edit] In 1921 Gnome-Rhône
purchased a license for the highly successful Bristol Jupiter
Bristol Jupiter
engine and produced it until about 1930, alongside the smaller Bristol Titan. Starting in 1926, however, they used the basic design of the Titan to produce a family of new engines, the so-called "K series". These started with the 5K Titan, followed by the 7K Titan Major and 9K Mistral. By 1930, 6,000 of these engines had been delivered. However, the aircraft industry at that time was rapidly evolving and producing much larger aircraft that demanded larger engines to power them. Gnome-Rhône
responded by developing the 7K into a two-row version that became the 14K Mistral Major. The first test examples were running in 1929. As the Jupiter had set the pattern for one-row radials in the 1920s, the Mistral Major became a canonical design for twin-row radials of the 1930s. It was widely licensed and formed the basis for many successful designs. Among the licensees were Industria Aeronautică Română, Manfred Weiss in Hungary, Alvis of the UK, Tumansky in the USSR, Walter of Czechoslovakia, Isotta Fraschini
Isotta Fraschini
and Piaggio
in Italy. Nakajima in Japan
also licensed it, but did not put it into production, developing their own designs based on features taken from the Mistral and other designs. Variants[edit]

Kbr Kbrs Kdr un-supercharged with reduction gearing Kds direct drive with supercharger Kdrs supercharged with reduction gearing Kes Kirs Knrs Krsd ? Kors opposite rotation to Kors Manfred Weiss WM K.14 Piaggio
P.XI IAR 14K Tumansky M-87 ИАМ K.14 Isotta Fraschini
Isotta Fraschini


Amiot 143 Aero A.102 Bloch MB.200 Bloch MB.210 Breguet 274 Breguet 460 Breguet 462 Breguet 470 Breguet 521 Breguet 670 Dornier Do 17K Farman F.222 Loire 46
Loire 46
C1 Makhonine Mak-101 PZL P.24 PZL P.43 Potez 501 Potez 506 Potez 62 Potez 651

Aircraft powered by G-R 14K derivatives[edit]

Aero A.102 Breda Ba.65 Breda Ba.88 CANT Z.1007 CANT Z.1011 Caproni Ca.135 Caproni Ca.161 Heinkel He 70 IAR 37 IAR 80 Ilyushin DB-3 MÁVAG Héja Reggiane Re.2000 Saab 17 Savoia-Marchetti SM.79 Savoia-Marchetti SM.84 Sukhoi Su-2 Weiss WM-21 Sólyom

Specifications ( Gnome-Rhône
14Kd)[edit] Data from [1][2] General characteristics

Type: Fourteen-cylinder two-row air-cooled radial engine Bore: 146 mm (5.748 in) Stroke: 165 mm (6.496 in) Displacement: 38.673 l (2,360.0 cu in) Length: Kds - 1,317 mm (51.85 in)

Kdr - 0.5 reduction gear - 1,528 mm (60.16 in) Kdr - 0.666· reduction gear - 1,530 mm (60.24 in) Kdrs - 0.5 reduction gear - 1,554 mm (61.18 in) Kdrs - 0.666· reduction gear - 1,556 mm (61.26 in)

Diameter: 1,288 mm (50.71 in) Dry weight: Kdr 0.5 reduction gear - 503 kg (1,109 lb)

Kdr 0.666· reduction gear - 508 kg (1,120 lb) Kdrs 0.5 reduction gear - 523 kg (1,153 lb) Kdrs 0.666· reduction gear - 528 kg (1,164 lb) Kds 502 kg (1,107 lb)


Valvetrain: Two Overhead valves per cylinder operated by pushrods Supercharger: (Kds / Kdrs - Single-speed centrifugal type supercharger) Fuel system: Stromberg carburetor Fuel type: 87 octane rating gasoline Cooling system: Air-cooled Reduction gear: Direct drive, 0.5:1 or 0.666·:1


Power output: Kdr - 600 kW (800 hp) at sea level

Kdrs - 580 kW (780 hp) at 1,500 m (4,900 ft) at 2,400 rpm Kdrs - 510 kW (680 hp) at 4,000 m (13,000 ft) at 2,400 rpm Kds - 560 kW (750 hp) at 1,500 m (4,900 ft) at 2,300 rpm Kds - 480 kW (650 hp) at 4,000 m (13,000 ft) at 2,300 rpm

Specific power: Kdr 15.5 kW/l (0.34 hp/in³) Compression ratio: 5.5:1 Specific fuel consumption: 328 g/(kW•h) (0.54 lb/(hp•h)) Oil consumption: 20 g/(kW•h) (0.53 oz/(hp•h)) Power-to-weight ratio: 1.52 kW/kg (0.92 hp/lb)

See also[edit]

Related development

IAR 14K Piaggio
P.XI Tumansky M-87

Related lists

List of aircraft engines


^ 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.  ^ Moteurs Gnome-Rhône
series K (PDF) (in Spanish). Paris: Société Des Moteurs Gnome-Rhône. Retrieved 3 October 2014. 

Danel, Raymond and Cuny, Jean. L'aviation française de bombardement et de renseignement 1918-1940 Docavia n°12, Editions Larivière

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