The Continental A-40 is a four-cylinder, air-cooled aircraft engine designed for light aircraft. It was developed in the 1940s and is known for its reliability and simplicity. The engine typically produces around 100 horsepower, making it suitable for small planes and training aircraft. This engine features a horizontally opposed configuration, which helps reduce vibration and improve balance. The A-40 is often used in vintage aircraft and is appreciated by aviation enthusiasts for its historical significance and performance in general aviation applications.