The Franklin O-150 (company designation 4AC-150) was an American air-cooled aircraft engine of the late 1930s (first run in 1938). The engine is of four-cylinder, horizontally-opposed layout with a displaced of 150 cubic inches. The first model used a single magneto. This engine has dual magnetos. This engine was used on a number of light… Continue reading 50 HP Franklin Aircraft Engine 4AC-150