The Lycoming R-680 is a nine-cylinder air-cooled radial engine, the first aero engine produced by Lycoming.
Pressure lubrication is to the crankshaft, master rod, link pins, cam drive gears, and main accessories drive shaft and gears.
First run in 1929, 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 for use without cylinder air baffles.
Equipment was a tachometer drive at ½ canshaft speed, exhaust ring, cowling and air cleaner.
Accessories available were a generator and starter.
Type: 9 cylinder air cooled radial
Rating: 210 hp at 2000 rpm
Displacement: 680 cu.in
Compression ratio: 5.2-1
Bore: 4 5/8 in
Stroke: 4 1/2 in
Length: 43 1/8 in
Diameter: 43 1/4 in
Weight: 465 lb dry
Fuel consumption: not more than .55 lb/hp/hr
Oil consumption: not more than .035 lb/hp/hr
Lubrication: 1 pressure pump, 2 scavenger pumps (in one unit)
Ignition: Scintilla dual magneto type SC-A
Carburation: 1 Stromberg NA-R7
Spark plugs: 2 per cylinder