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.
- Rated at 225 hp (168 kW) at 2100 rpm.
- Rated at 240 hp (180 kW)
- Rated at 285 hp (213 kW) at 2200 rpm.
- Rated at 245 hp (183 kW)
- Rated at 300 hp (220 kW) at 2200 rpm.
- Beech AT-10 Wichita
- Boeing-Stearman PT-13
- Cessna AT-8/AT-17
- Curtiss-Wright AT-9
- Fleetwings BQ-2
- Spartan NP-1
- Stinson Airliner
- Stinson Reliant
- Stinson Vigilant
- Waco S Series
Data from Jane's.
- 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)
- 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
- 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)
- Comparable engines
- Related lists
|Wikimedia Commons has media related to Lycoming R-680.|
- Bridgman 1988