The Gnome-Rhône 14K ''Mistral Major'' was a 14-cylinder, two-row, air-cooled

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

. It was Gnome-Rhône's major aircraft engine prior to

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

, and matured into a highly sought-after design that would see licensed production throughout

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

and Japan. Thousands of Mistral Major engines were produced, used on a wide variety of aircraft.

Design and development

In 1921 Gnome-Rhône purchased a license for the highly successful Bristol Jupiter engine and produced it until about 1930, alongside the smaller

Bristol Titan The Bristol Titan was a British five-cylinder air-cooled radial engine, designed and built by the Bristol Aeroplane Company in the late 1920s. It had the same size cylinders as the earlier Bristol Mercury engine, (displacing ), and produced ...

. 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 Industria Aeronautică Română (IAR) (now IAR S.A. Brașov) or Romanian Aeronautic Industry in English, is a Romanian aerospace manufacturer. It is based in Ghimbav, near Brașov, Romania. IAR was founded in 1925 with the aid of the Romanian g ...

in Romania, Manfred Weiss in Hungary, Alvis of the UK,

Tumansky Sergei Konstantinovich Tumansky (russian: Серге́й Константинович Туманский; – 9 September 1973) was a designer of Soviet aircraft engines and the chief designer in the Tumansky Design Bureau, OKB-300. He worked i ...

in the USSR, Walter of Czechoslovakia, and

Isotta Fraschini Isotta Fraschini () was an Italian luxury car manufacturer, also producing trucks, as well as engines for marine and aviation use. Founded in Milan, Italy, in 1900 by Cesare Isotta and the brothers Vincenzo, Antonio, and Oreste Fraschini, in 19 ...

and

Piaggio Piaggio & C. SpA (Piaggio ) is an Italian motor vehicle manufacturer, which produces a range of two-wheeled motor vehicles and compact commercial vehicles under seven brands: Piaggio, Vespa, Gilera, Aprilia, Moto Guzzi, Derbi, and Scarabeo ...

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

;14Kbr: Reduction gearing ;14Kbrs: Supercharged with reduction gearing ;14Kdr: Reduction gearing ;14Kds: Supercharger ;14Kdrs: Supercharged with reduction gearing ;14Kes: Supercharged (LH rotation) ;14Kfs: Supercharged (RH rotation Kers) ;14Kirs: Supercharged with reduction gearing (LH rotation) ;14Kjrs: Supercharged with reduction gearing (RH rotation Kirs) ;14Knrs: Supercharged with reduction gearing (LH rotation) ;14Kors: Supercharged with reduction gearing (RH rotation Knrs) ; Alvis Pelides :Development of engine with British fasteners. 15 built before project abandoned with start of Second World War as no suitable use in Air Ministry plans. ;Isotta Fraschini K.14: license-built in Italy by

; IAM K14: licensed derivative produced in Yugoslavia ;

IAR K14 The IAR K14 was a Romanian 14-cylinder radial aircraft engine. The IAR K14 was a licensed derivative of the French Gnome-Rhône 14K Mistral Major produced in Romania.Gunston 1989, Variants ;IAR K14-I 40: ;IAR K14-I C32: 693 kW (930&nbs ...

: licensed derivative produced in Romania ; Manfréd Weiss WM K-14:licensed derivative produced in Hungary ;

Piaggio P.XI The Piaggio P.XI was an Italian 14-cylinder radial aircraft engine. The P.XI was a licensed derivative of the French Gnome-Rhône Mistral Major 14K produced in Italy.Gunston 1989, p.110. Isotta Fraschini also produced a version of the 14K ca ...

: licensed derivative produced in Italy ;

Piaggio P.XIX The Piaggio P.XIX was an Italian aircraft engine produced by Piaggio Aerospace, Rinaldo Piaggio S.p.A. during World War II and used to power aircraft of the Regia Aeronautica. Development The engine was part of a line of 14-cylinder radial engines ...

: higher compression development of

;Tumansky M-85: license-built in USSR by

;Tumansky M-86: 960 hp (715 kW) development of M-85 through increased supercharging and a higher compression ratio. ;

Tumansky M-87 The Tumansky M-87 was a Soviet air-cooled aircraft radial engine that was developed in the late 1930s. It was a development of their licensed Gnome-Rhone 14K engines that started with the M-85. Development In 1934, USSR licensed the French G ...

: ;

Tumansky M-88 The Tumansky M-88 was an air-cooled radial engine for aircraft developed in the Soviet Union shortly before World War II. Design and development The M-88 was designed to address the shortcomings of the Tumansky M-87. The improvements incorporat ...

: ;Walter Mistral Major: ;ИАМ K.14:

Applications

Aircraft powered by G-R 14K derivatives

Specifications (Gnome-Rhône 14Kd)

Gallery

File:Piaggio-P.XI.jpg, A Piaggio P.XI engine at the Malmohus Technical Museum, Malmo, Sweden. File:Tumanski M-85 Keski-Suomen ilmailumuseo.JPG, A Tumansky M-85 at the Aviation Museum of Central Finland. File:Walter Mistral K 14-I (1934-37).jpg, Walter Mistral Major. File:Walter Mistral K-14 MLP 01.jpg, A Walter Mistral Major at the Polish Aviation Museum in Krakow.

References

* Danel, Raymond and Cuny, Jean. ''L'aviation française de bombardement et de renseignement 1918-1940'' Docavia n°12, Editions Larivière {{DEFAULTSORT:Gnome-Rhone Mistral Major 1920s aircraft piston engines Aircraft air-cooled radial piston engines Mistral Major K.14 M-85