The McCulloch O-100 is a four-cylinder, air cooled four piston drone engine developed by the McCulloch Aircraft Corporation (later to become the McCulloch Motors Corp.) which was founded 1943 in Milwaukee, Wisconsin and later moved to Los Angeles, California. The aircraft corporation was formed from the McCulloch Engineering Company.
In 1972, the corporation was renamed McCulloch Motors Corp. of Los Angeles and sold to Northrop-Ventura.
The McCulloch line of engines consisted of small 1, 2, 4 and 6 cylinder 2-stroke engines. The first engines were used for industrial motor pumps and chainsaws. In the 1940s, military contract started with a 4-cylinder model 4300 (Military O-88) engine to be used in aeronautical target drones. Later with bigger Horsepower (H.P.) development, the engines had experimental aircraft applications.
Horizontally-Opposed Piston Engines