The Green C.4 was a British four-cylinder, water-cooled aero engine that first ran in 1908, it was designed by Gustavus Green and licensed by his Green Engine Co for manufacture by Aster Engineering. The engine was one of two Green designs to win a government prize.[1]
A preserved Green C.4 engine is on public display at the Royal Air Force Museum London. Another engine is on display at the National Museum of Flight in Scotland..