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.
In Germany Motorenfabrik Oberursel license-built the seven-cylinder engine as the Oberursel U.0

Used in the Caspar U 2
Type 7-cylinder, single-row, rotary engine Compressor No Reduction Gear Direct drive , right hand tractor, left hand pusher Length 112 cm
Operation 4-stroke Bore 124 mm   Compression ratio 3,86 Height 93 cm
Mixture Carburettor Stroke 140 mm   Fuel consumption 315 g/hp Width/diameter
 93 cm
Cooling Air-cooled Displacement 11820 cm3 Oil consumption 80 g/hp Weight 96 kg
Power output 84 hp at 1190 rpm