For over seven decades, the Lycoming O-320 series engine has been powering light aircraft, defying the conventional wisdom that new technology is always better than old. Introduced in the late 1950s, this four-cylinder, air-cooled piston engine remains in use today, thanks to its unique design and exceptional performance.
The O-320’s compact size allows for efficient cooling and improved aerodynamic performance. Its horizontally opposed configuration enables a lower profile, while its direct drive system connects the motor to the propeller at the front of the crankshaft, minimizing power loss. The engine also features a magneto ignition system that generates electrical power, eliminating the need for external power.
With a 320-cubic-inch displacement and rated between 150-160 horsepower, the O-320 is a powerhouse in its class. Its dry weight is relatively low at 244 pounds, making it an attractive option for pilots. The engine has powered several iconic planes, including the Piper PA-18 Super Cub, PA-28 Cherokee, Grumman AA-5, and Cessna 172 Skyhawk.
Despite not being a revolutionary engine that changed aviation forever, the O-320’s reputation as a reliable and durable workhorse is well-deserved. Its maintenance simplicity has allowed it to remain in use for over seven decades, cementing its place among the greats of airplane engineering.
Source: https://www.slashgear.com/1882869/airplane-piston-engine-70-years-old-how-much-power