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.

Design and development
In 1921 Gnome-Rhône purchased a license for the highly successful nine-cylinder single-row Bristol Jupiter radial engine and produced it until about 1930, alongside the smaller five-cylinder Bristol Titan. Starting in 1926, however, they used the basic design of the Titan to produce a family of new single-row radial engines, the so-called "K series". With increasing numbers of cylinders, 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 in Romania, Manfred Weiss in Hungary, Alvis of the UK, Tumansky in the USSR, Walter of Czechoslovakia, and 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

 * 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 Isotta Fraschini
 * IAM K14: licensed derivative produced in Yugoslavia
 * IAR K14: licensed derivative produced in Romania
 * Manfréd Weiss WM K-14:licensed derivative produced in Hungary
 * Piaggio P.XI: licensed derivative produced in Italy
 * Piaggio P.XIX: higher compression development of Piaggio P.XI
 * Tumansky M-85: license-built in USSR by Tumansky
 * Tumansky M-86: 960 hp (715 kW) development of M-85 through increased supercharging and a higher compression ratio.
 * Tumansky M-87:
 * Tumansky M-88:
 * Walter Mistral Major:
 * ИАМ K.14:

Applications
• Amiot 143

• Aero A.102

• Bloch MB.200

• Bloch MB.210

• Breguet 274

• Breguet 460

• Breguet 462

• Breguet 470

• Breguet 521

• Breguet 670

• Dewoitine D.371

• Dornier Do 17K

• Farman F.222

• Loire 46 C1

• Makhonine Mak-101

• PZL P.24

• PZL.43

• Potez 501

• Potez 506

• Potez 62

• Potez 651

Aircraft powered by Gnome-Rhône 14K derivatives
• 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 Manfréd WM-16B Budapest II

• Weiss Manfréd WM-21 Sólyom

• Weiss Manfréd WM-23 Ezüst Nyíl