The Lycoming O-320 series engines are four-cylinder, direct-drive, horizontally opposed, air-cooled models. The cylinders are of conventional air-cooled construction with heads made from an aluminum-alloy casting and a fully machined combustion chamber. The cylinder barrels are machined from chrome nickel molybdenum steel forgings with deep integral cooling fins, ground and honed to a final specified finish. The O-320 series engines are equipped with a float-type carburetor. Particularly good distribution of the fuel-air mixture to each cylinder is obtained through the center-zone induction system, which is integral with the oil sump and is submerged in oil, ensuring a more uniform vaporization of fuel and aiding in cooling the oil in the sump. In addition, the IO-320 has a fuel injector. The fuel-injection system schedules fuel flow in proportion to airflow. Fuel vaporization takes place at the intake ports.
Forged-steel connecting rods
Optional chrome kit
Nitride hardened steel alloy cylinder barrels
Forged-steel crankshafts
Chromium-modified ni-resist iron exhaust-valve guides, resulting in better wear characteristics
Forged-steel camshafts
O-320 series engines power numerous popular aircraft, including:
Piper Shawnee
Cherokee
Cherokee Cruiser
Super Cub, Apache
Cadet
Tri-pacer
Warrior II
Cessna Skyhawk
Grumman’s Cougar and Traveler
The Beech Musketeer, Musketeer III, and Sport
Kit planes from Van’s, Stoddard Hamilton, and Lancair
Bellanca’s Citabria
Socata’s Tampico.
