Gnome 7 Lambda
In 1895 Louis Seguin bought a license for the Gnom gas engine from the German firm Motorenfabrik Oberursel. Itwas a single-cylinder stationary engine of about 4 hp that ran on kerosene . On 6 June 1905 Louis Seguin and his brother Laurent formed the « Société Des Moteurs Gnome » to produce automobile engines. They soon started development of one of the first purpose-designed aircraft engines, combining several Gnome cylinders into a rotary engine.
 
The first 25hp engine was built during the winter of 1907-1908 in the « Société des Moteurs Gnome » workshop situated on the banks of the Seine river in Petit-Gennevilliers. It was characterised by the rotation of the cylinders and the engine block around a fixed crankshaft bolted to the aircraft's airframe. The design evolved into the 50hp Omega model, which was displayed at the first Paris Air Show in December 1908. It caused a sensation because it was the first reliable engine to operate without vibration, power loss or overheating.
 
Production started in July 1909, and by August 1914, 60% of the French aircraft was powered with a Gnome engines . After a 14-cylinder Double Omega version, a new 80hp 7-cylinder engine named Lambda was certified in 1912. It was the first engine to pass the official qualifications of the military aviation engine test centre at Chalais-Meudon. 

More than 3,000 Lambda engines were built in France, and 979 under licence in the UK. 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. 

Main aircraft powered by the Lambda engine: Blériot XI military, Farman HF-20, Nieuport 10, Bristol Scout, Sopwith Tabloid, Morane-Saulnier L.

Status:

The BAPA engine is construction number 7137. It was donated by a generous donator who wishes to remain anonymous. Mounted on a stand, it is missing a few parts and all the accessories.

Above: a Gnome company publicity for the Gnome Lambda 7
Here under: the Gnome Lambda 7 as received, corrosion is only superficial and has been already mostly removed.

characteristics :                       

7 cylinder air-cooled rotaryengine


Power: 80 hp 
Bore: 124 mm 
Stroke: 140 mm 
Displacement: 11828 cm3 
Compression ratio: 3.75:1 
Weight: 87 kg 
Diameter: 93 cm 
Length: 112 cm