The Lycoming R-680 is a nine-cylinder air-cooled

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance (geometry), a directional coordinate in a polar coordinate system * Radial set * A ...

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. R-680 received Approved Type Certificate No. 42 on 4 Feb 1930.

Variants

;R-680 :Rated at at 2,000 rpm. ;R-680B4E :Rated at at 2,100 rpm.Bridgman 1988 ;R-680BA :Rated at ;R-680E3A :Rated at at 2,200 rpm. ;R-680-6 :Rated at ;R-680-9 :Rated at at 2,200 rpm. ;R-680-13 :Rated at at 2,200 rpm.

Applications

Beech AT-10 Wichita The Beechcraft Model 18 (or "Twin Beech", as it is also known) is a 6- to 11-seat, twin-engined, low-wing, tailwheel light aircraft manufactured by the Beech Aircraft Corporation of Wichita, Kansas. Continuously produced from 1937 to November ...

Boeing-Stearman PT-13 The Stearman (Boeing) Model 75 is an American biplane formerly used as a military trainer aircraft, of which at least 10,626 were built in the United States during the 1930s and 1940s. Stearman Aircraft became a subsidiary of Boeing in 1934. Wi ...

* Cessna AT-8/AT-17 *

Curtiss-Wright AT-9 The Curtiss-Wright AT-9 Jeep is an American twin-engined advanced trainer aircraft used by the United States during World War II to bridge the gap between single-engined trainers and twin-engined combat aircraft. The AT-9 had a low-wing cantil ...

Fleetwings BQ-2 The Fleetwings BQ-2 was an early expendable unmanned aerial vehicle — referred to at the time as an " assault drone" — developed by Fleetwings during the Second World War for use by the United States Army Air Forces. Only a single example o ...

Spartan NP-1 The Spartan NP-1 was a two-seat primary trainer designed and built by the Spartan Aircraft Company for the United States Navy reserve units. Development On 10 July 1940 the company received an order from the United States Navy for 201 aircraft ...

Stinson Airliner The Stinson SM-6000 Airliner was a 1930s three-engined (trimotor) ten-passenger airliner designed and built by the Stinson Aircraft Company, Stinson Aircraft Corporation. The SM-6000 was a high-wing braced monoplane with room for a pilot and a ca ...

Stinson Reliant The Stinson Reliant is a popular single-engine four- to five-seat high-wing monoplane manufactured by the Stinson Aircraft Company, Stinson Aircraft Division of the Aviation Manufacturing Corporation of Wayne, Michigan. Design and development ...

Stinson L-1 Vigilant The Stinson L-1 Vigilant (company designation Model 74) is an American liaison aircraft designed by the Stinson Aircraft Company of Wayne, Michigan and manufactured at the Vultee-Stinson factory in Nashville, Tennessee (in August 1940 Stinson be ...

Waco S Series The Waco S Series is a family of American cabin biplanes produced by the Waco Aircraft Company starting in 1935. Development and designations The Waco closed cabin biplanes, initially known as the C (for Cabin) series were all unequal span, sta ...

Specifications (R-680-E3A)

References

Notes

Bibliography

* {{US military piston aeroengines 1920s aircraft piston engines Aircraft air-cooled radial piston engines