Gnome Lambda

Lambda
The Sopwith Tabloid replica on display at the Royal Air Force Museum is fitted with an original Gnome 7 Lambda engine.
Type	Rotary aero engine
Manufacturer	Gnome et Rhone
First run	c.1916
Major applications	Avro 504 Bristol Boxkite Bristol Scout
Number built	979 (British production)

The Gnome 7 Lambda was a French designed, seven-cylinder, air-cooled rotary aero engine that was produced under license in Britain and Germany. Powering several World War I era aircraft types it was claimed to produce 80 horsepower (60 kW) from its capacity of 12 litres (720 cubic inches) although recorded figures are lower.

Just under 1,000 units were produced in Britain, the majority (967) by the Daimler Company of Coventry. A 14-cylinder variant was known as the Gnome 14 Lambda-Lambda.

In Germany Motorenfabrik Oberursel license-built the seven-cylinder engine as the Oberursel U.0 and later copied the 14-cylinder design and designated it as the Oberursel U.III.

Variants

Gnome 7 Lambda

Seven-cylinder, single-row rotary engine.

Gnome 7 Lambda (long stroke)

Increased stroke of 145 mm (5.7 in) to raise the compression ratio to 3.87:1, and total displacement to 12.26 litres.

Gnome 14 Lambda-Lambda

14-cylinder, two-row rotary engine using Lambda cylinders. 160 hp (120 kW).

Motorenfabrik Oberursel U.0

German production of the Gnome 7 Lambda - had a 124mm cylinder bore and 140mm piston stroke for a total displacement of 11.52 litres, external diameter of 1.020 meters.

Applications

List from Lumsden

Gnome 7 Lambda

• Avro 504
• Blackburn Type I
• Borel hydro-monoplane
• Blériot Parasol
• Blériot XI
• Bristol Boxkite
• Bristol Gordon England G.E.3
• Bristol-Coanda Monoplanes
• Bristol Coanda T.B.8
• Bristol Coanda P.B.8
• Bristol Scout
• Caudron G.III
• Deperdussin Type B
• Dunne D.8
• Henry Farman F.20

• Grahame-White Type XV
• London & Provincial 4
• Lowe Marlburian
• Nieuport IVG
• Nieuport 10
• Radley-England Waterplane
• Royal Aircraft Factory B.E.3
• Royal Aircraft Factory B.E.4
• Royal Aircraft Factory B.E.8
• Royal Aircraft Factory B.S.1
• Royal Aircraft Factory S.E.2
• Royal Aircraft Factory S.E.2

• Royal Aircraft Factory S.E.4
• Short S.37
• Short S.38
• Short S.41
• Short S.60
• Short S.70
• Sopwith Gordon Bennett Racer
• Sopwith Pup
• Sopwith Sociable
• Sopwith Tabloid
• Sopwith Three-Seater
• Vickers No.8 Monoplane

Gnome 14 Lambda-Lambda

• Avro 510
• Royal Aircraft Factory S.E.4
• Deperdussin Monocoque
• Short S.63
• Short S.64
• Short S.70
• Short S.74
• Short S.80
• Short S.81
• Short S.82

Survivors

An original Gnome 7 Lambda engine is installed in the Sopwith Tabloid replica aircraft on display in the Grahame-White hall of the Royal Air Force Museum London.

Specifications (Gnome 7 Lambda)

File:Umlaufmotor1.jpg

Oberursel U.III, a 14-cylinder copy of the Gnome Lambda-Lambda

Data from Lumsden.

General characteristics

• Type: 7-cylinder, single-row, rotary engine
• Bore: 124 mm (4.9 in)
• Stroke: 140 mm (5.5 in)
• Displacement: 11.8 L (721.2 cu in)
• Length: 112 cm (44 in)
• Diameter: 93 cm (36.6 in)
• Dry weight: 96 kg (212 lb)

Components

• Valvetrain: Automatic centre-piston inlet valve, overhead exhaust valve (one each per cylinder)
• Cooling system: Air-cooled
• Reduction gear: Direct drive, right-hand tractor, left-hand pusher

Performance

• Power output: 50.3 kW (67.5 hp) at 1,250 rpm (maximum power)
• Compression ratio: 3.75:1

See also

Comparable engines

• Clerget
• Le Rhône

Related lists

• List of aircraft engines

References

Bibliography

• Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.