Gnome-Rhône 7K

7K
Type	Radial engine
Manufacturer	Gnome et Rhône

The Gnome-Rhône 7K Titan Major was a seven-cylinder 370 hp (270 kW) air-cooled radial engine, that started life as an enlarged Gnome-Rhône 5K with two extra cylinders.

Development

The Gnome-Rhône 5K was itself a licensed version of the Bristol Titan. The 7K is very comparable to the Bristol Neptune seven-cylinder engine since they used the same technology.^[1] The 7K was followed by the larger and more powerful nine-cylinder 550 hp (405 kW) Gnome-Rhône 9K Mistral. Gnome-Rhône later responded to the need for a more powerful engine by developing the 7K into a two-row version that became the Gnome-Rhône14K Mistral Major.

Variants

IAM K7: Licence production in Yugoslavia by Industrija Aeroplanskih Motora- Rakovica (IAM).
IAR 7K: Licence production in Romania by Industria Aeronautică Română (IAR).

Applications

A Nationalist China Breda Ba.28, powered by a Piaggio-built Gnome-Rhône 7K

Specifications (7Kd)

Data from ^[2]

General characteristics

Type: Seven-cylinder air-cooled radial engine.
Bore: 146 mm (5.75 in)
Stroke: 165 mm (6.50 in)
Displacement: 19.3 L (1,180 cu in)
Length: 146 mm (5.75 in)
Diameter: 1,235 mm (48.62 in)
Dry weight: 270 kg (600 lb)

Components

Valvetrain: Pushrod operated overhead valves, two per cylinder
Supercharger: (7Ksd - single speed centrifugal blower)
Fuel system: Carburetor
Fuel type: Gasoline
Cooling system: Air-cooled

Performance

Power output: 7Kd - 260 kW (350 hp) at 2,000 rpm at sea level for take-off
7Ksd - 272 kW (365 hp) at 2,000 rpm at 1,500 m (4,900 ft)

7Ksd - 250 kW (340 hp) at 2,000 rpm at 4,000 m (13,000 ft)
Compression ratio: 5.5:1

References

Notes

^ Gunston 1989, p.74.
^ Moteurs Gnome-Rhône series K (PDF) (in Spanish). Paris: Société Des Moteurs Gnome-Rhône. Archived from the original (PDF) on 6 October 2014. Retrieved 3 October 2014.

Bibliography

Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

[1] Gunston 1989, p.74.

[GetRKseries-2] Moteurs Gnome-Rhône series K (PDF) (in Spanish). Paris: Société Des Moteurs Gnome-Rhône. Archived from the original (PDF) on 6 October 2014. Retrieved 3 October 2014.

[1]

[2]