Gnome-Rhône 18L

The Gnome et Rhône 18L was a French-designed twin-row 18-cylinder air-cooled radial engine. The 18L was a large step up in terms of displacement, power and number of cylinders. The majority of Gnome-Rhone engines were either 7, 9 or 14 cylinders. The engine was never put into series production due to the negligible market interest and the company's concentration on the production of 14-cylinder engines, which very quickly approached the performance of the larger model. However, the 18-cylinder model was further developed in the versions 18P with a two-speed compressor (1650 cv, 2400 rpm) and 18R with a central bearing (2150 cv, 2500 rpm), the latter variant achieved in tests in 1946 a power of 2400 cv at 2600 rpm. Eventually SNECMA (the successor of Gnome et Rhône) undertook licensed production of the Bristol Hercules engine instead.

18L
Type	Radial engine
National origin	France
Manufacturer	Gnome et Rhône

Specifications (Gnome Rhone 18L-00)

Data from Flight:POWER at the SALON^[1]

General characteristics

• Type: 18-cylinder twin-row air-cooled radial engine
• Bore: 146 mm (5.7 in)
• Stroke: 180 mm (7.1 in)
• Displacement: 54.2 L (3,310 cu in)
• Height: 1,400 mm (55 in)
• Dry weight: 736 kg (1,623 lb)

Components

• Valvetrain: 1 inlet and 1 exhaust valve per cylinder
• Supercharger: Yes
• Fuel system: 1 Bronzania Carburetor
• Fuel type: 87 octane
• Cooling system: air
• Reduction gear: 0.684:1

Performance

• Power output: 970 kW (1,300 hp) at 2,170 rpm at 3,400 m (11,000 ft); 1,000 kW (1,400 hp) max
• Compression ratio: 5.5:1
• Power-to-weight ratio: 0.8 hp/lb at cruise speed

See also

Comparable engines

• Alfa Romeo 135
• BMW 802
• Bristol Centaurus
• Fiat A.82
• Nakajima Homare
• Pratt & Whitney R-2800 Double Wasp
• Tumansky M-90
• Wright R-3350 Duplex-Cyclone

Related lists

• List of aircraft engines