Lycoming R-680 Radial Engine General characteristics Type: Nine cylinder air-cooled radial Bore: 4 5⁄8 in (117 mm) Stroke: 4 1⁄2 in (114 mm) Displacement: 680 in³ (11.15 litres) Length: 37.5 in (953.1 mm) Diameter: 43.5 in (1104 mm) Dry weight: 515.46 lb (233.9 kg) Components Valvetrain: One inlet and one exhaust valve per cylinder at 30 degrees. Fuel system: single-barrel carburetor Fuel type: 87 octane rating gasoline Oil system: Full pressure type Cooling system: Air-cooled Performance Power output: 330 hp (246 kW) at 2,300 rpm at sea level Compression ratio: 7:1 Power-to-weight ratio: 0.64 hp/lb (1.05 kW/kg) The Lycoming R-680 is a nine-cylinder air-cooled radial engine, the first aero engine produced by Lycoming. The engine was produced in two types, the E and B series; both are essentially the same. The B4E was available in a trainer version with a front exhaust collector "ring" for use without cylinder air baffles.
The Lycoming R-680 is a nine-cylinder air-cooled radial engine, the first aero engine produced by Lycoming. The engine was produced in two types, the E and B series; both are essentially the same. The B4E was available in a trainer version with a front exhaust collector "ring" for use without cylinder air baffles.
