Lycoming began as a subsidiary of the Auburn Auto Company, and the R-680 was a development version of its first 138 kW (185 hp) aircraft engine. It was one of a number of engines designed to replace the ubiquitous Curtiss OX-5 following World War I. The R-680 was type certificated in early-1930, and originally rated at 157 kW (210 shp). Considered a very reliable engine, more than 26,000 were built before production ended following World War II.

The R-680 powered the Stearman PT-13 primary American military trainer during the 1930s and 1940s, for which more than 2,000 engines were built. This model R-680-9 was an Army Air Forces engine that powered the Stinson L-1 and L-12, Curtiss AT-9/A, Beech AT-10, Stearman PT-9B, and Stinson CQ-2 aircraft.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date Circa 1940 Country of Origin United States of America Type PROPULSION-Reciprocating & Rotary Manufacturer Lycoming (Williamsport, Pennsylvania)
 Physical Description Type: Reciprocating, 9 cylinders, radial, air-cooled Power rating: 220 kW (295 hp) at 2,300 rpm Displacement: 11.1 L (680 cu in) Bore and Stroke: 117 mm (4.6 in.) X 114 mm (4.5 in.) Weight: 248 kg (547 lb) Dimensions Approximate: 99.1 × 109.2 × 109.2cm (39 × 43 × 43 in.)
Storage: 134.6 × 132.7 × 162.6cm (53 in. × 52 1/4 in. × 64 in.)
Overall: 547lb. (248.1kg)
Other: 43 1/4 x 37 1/2in. (109.9 x 95.3cm)
 Materials Magnesium Alloy
Steel
Aluminum
Stainless Steel
Copper Alloy
Rubber
Paint
Phenolic Resin
Natural Fabric
Paper
 Inventory Number A19860279000 Credit Line Gift of San Jose State University Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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