The Gnome-Rhône 9K Mistral was a nine-cylinder 550 hp (405 kW) to 700 hp air-cooled radial engine, that started life as an enlarged Gnome-Rhône 7K with two extra cylinders.

The Gnome-Rhône 7K itself was an enlarged version of the Gnome-Rhône 5K which was derived from a licensed version of the Bristol Titan . A redesign of the cylinders is indicated by the K suffix. The 9K was followed by the larger and more powerful 14-cylinder twin row Gnome-Rhône 14K.
The 9K was also produced in the Soviet Union as the M-75 at factory No. 29 in Zaporozhye. Only small numbers were built and it was dropped in favor of the M-25 a version of the Wright Cyclone and the M-85 a version of the 14K Mistral Major.

The 9K was license produced by Hungarian company Weiss Manfréd Repülogép- és Motorgyár Rt. (WM Rt, the aircraft engine factory of Manfred Weiss). The engine was used successfully in the MÁVAG Héja and Weiss WM-21 Sólyom aircraft.

Licence production in Romania by Industria Aeronautică Română (IAR) was carried out as the I.A.R. 9KIc40.

Variants:
9K
9Krs
9Kd
9Krse
9Kdr
9Kfr
9Kbr
I.A.R. 9KIc40
Weiss MW 9K Mistral Tumansky M-75

Applications:
IAR 15
Breguet Calcutta
Loire 70
Morane-Saulnier MS.225
Savoia Marchetti S73 (license build Piaggio Stella P.IX)
Savoia Marchetti SM81 (license build Piaggio Stella P.IX)
SNCAC NC.510
Wibault 313
Wibault 365

Specifications:
Type: Nine-cylinder air-cooled radial engine.
Bore: 5.75 in (146 mm)
Stroke: 6.5 in (165 mm)
Displacement: 1,517in³ (24.9 Liters)
Fuel system: Carburetor
Cooling system: Air-cooled