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Pierre Clerget was inspired by the Gnome to produce a supposedly improved rotary engine in 1911. It was a 7-cylinder, 11.88 liter (725 cu in) engine rated at 60 kW (80 hp) at 1,200 rpm. Thousands of these engines were manufactured in France and Britain. Larger 9-cylinder rotary engines began production in 1913. In the 1920s, Clerget transitioned to 4-stroke diesel engines, which initially had dimensions similar to the rotaries. The Clerget 9A was built by Clerget, Blin, and Cie of Paris, France, with development beginning in 1928. On September 28, 1929, in a Morane 135 aircraft, it became the first diesel aircraft engine to fly in France. This engine was followed by the 149 kW (200 shp) 9B in 1930, the 186 kW (250 shp) 9Br (which was reversible in flight) in 1931, and the 224 kW (300 shp) 9C in 1932.