Le Rhone Model J 9 Cylinder Rotary Engine

Type: Rotary, 9 cylinders, air-cooled

Power rating: 82 kw (110 hp) at 1,200 rpm

Displacement: 15.1 L (919.71 cu. in.)

Bore and Stroke: 112 mm (4.41 in.) x 170 mm (6.69 in.)

Weight: 146.6 kg (323 lb)

Used mainly on fighter aircraft where speed and maneuverability were especially important, rotary engines were light and compact for their power. Societe des Moteurs Le Rhone of Paris began manufacturing air cooled rotary engines in 1910. Its rotary was sufficiently different than that first developed by the highly successful Seguin brothers of the Societe des Moteurs Gnome, also of Paris, that it circumvented relevant Gnome patents; but was taken over by Gnome in 1914. Because Le Rhone products were in some ways superior to Gnome, its design engineers were permitted to continue development during World War I, resulting in large scale production of various nine cylinder engines.

This engine was also produced under license in Sweden by Thulin. Oberursel supposedly produced the engine without authorization in Germany. It powered Caudron, Nieuport, Morane, Hanriot, Fokker, and DH 5 aircraft.