9K
Type	Radial engine
Manufacturer	Gnome et Rhône
Developed into	Piaggio Stella P.IX

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 license produced by Hungarian company Weiss Manfréd Repülogép- és Motorgyár Rt. (WM Rt, the aircraft engine factory of Manfred Weiss). The 9K was also produced in the Soviet Union as the M-75 at GAZ-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 Gnome-Rhône 14K Mistral Major.

9K

9Kbr

9Kdr

9Kdrs

9Kers

9Kfr

I.A.R. 9KIc40

Licence production in Romania by Industria Aeronautică Română (IAR).

• Breguet Calcutta
• IAR-15
• Loire 70
• Morane-Saulnier M.S.225
• SNCAC NC.510
• Wibault 313
• Wibault 365

Data from ^[1]

• Type: Nine-cylinder air-cooled radial engine.
• Bore: 146 mm (5.75 in)
• Stroke: 165 mm (6.50 in)
• Displacement: 24.9 L (1,520 cu in)
• Length: Kdr 0.5 reduction gear - 1,295 mm (50.98 in)

  Kdr 0.666· reduction gear - 1,297 mm (51.06 in)

  Kdrs 0.5 reduction gear - 1,323 mm (52.09 in)

  Kdrs 0.666· reduction gear - 1,325 mm (52.17 in)

• Diameter: 1,299 mm (51.14 in)
• Dry weight: Kdr 0.5 reduction gear - 355 kg (783 lb)

  Kdr 0.666· reduction gear - 360 kg (790 lb)

  Kdrs 0.5 reduction gear - 369 kg (814 lb)

  Kdrs 0.666· reduction gear - 374 kg (825 lb)

• Valvetrain: Two valves per cylinder, pushrod operated
• Supercharger: Kdrsd - single stage centrifugal blower
• Fuel system: Carburetor
• Fuel type: Gasoline
• Cooling system: Air-cooled
• Reduction gear: Direct drive, 0.5:1 or 0.666·:1

• Power output: Kdr - 370 kW (500 hp) at sea level

  Kdrs - 370 kW (500 hp) at 1,500 m (4,900 ft)

  Kdrs - 340 kW (450 hp) at 4,000 m (13,000 ft)

• Compression ratio: 5.5:1

Related development

• Piaggio Stella P.IX
• Tumansky M-90

Comparable engines

• BMW 132
• Bramo 323
• Bristol Mercury
• Piaggio P.X
• Pratt & Whitney R-1340 Wasp

Related lists

• List of aircraft engines

Wikimedia Commons has media related to Gnome et Rhône 9K Mistral.