Closely following the design of many full-size light aircraft engines, the O.S. Pegasus 320 is a horizontally opposed four cylinder engine. The Pegasus is unique: it is the only flat four model aircraft engine on the market. It is powerful, yet very easy to handle and incredibly free from vibration. It features pushrod OHV, seven ball bearings, ringed pistons and a special propeller locknut assembly as standard. The FF-320 Pegasus is a unique engine that will exceed all your performance and quality expectations.