This Operators Manual covers the Lycoming 320 series of reciprocating aircraft engines, manufactured by Lycoming Engines. These engines are designed for aviation propulsion and are characterized by their horizontally opposed, air-cooled, four-cylinder configuration with a displacement of 320 cubic inches. The series includes models such as the O-320, IO-320, AIO-320, and LIO-320, which may feature naturally aspirated or fuel-injected aspiration systems. Engineered for reliability and performance in aviation applications, these engines represent a significant contribution to aircraft power systems.

This manual provides essential information for the operation and maintenance of your Lycoming 320 series aircraft engine. It details critical aspects including operating parameters, technical specifications, and recommended maintenance procedures, such as oil type and capacity, which may require reference to specific model data sheets or Lycoming Service Information Letters. The content is designed to assist operators, mechanics, and technicians in ensuring the continued safe and efficient performance of their aircraft engines through comprehensive guidance.