Lycoming Engines

 ( Textron ) 

By 1920, Lycoming was producing 60,000 engines a year, with a 2,000-strong workforce. To handle the capacity, a new foundry complex was built in Williamsport that year. Eventually Lycoming became Auburn's principal supplier, and in 1927 Errett Lobban Cord bought the company, placing it under his Auburn Manufacturing umbrella group.

Among the engines Lycoming produced for Cord was an L-head straight-eight engine of 298.5 cu. in. displacement that produced 125 horsepower. This was used in the Cord L-29. Lycoming also produced a double overhead cam straight 8 used in the legendary Duesenberg J series. This powerplant produced 265 horsepower, six times the power of a contemporary Model A Ford. A supercharged version, generating 325 horsepower, was installed in the Duesenberg SJ and SSJ models.

In 1929, Lycoming produced its first aviation engine, the nine-cylinder R-680 radial engine. This was a fairly successful design, and was used widely in light aircraft, including Cord's Travel Air.

In the 1930s, Lycoming made a number of attempts to develop successful high-power aircraft engines. The O-1230 was Lycoming's attempt to produce an engine based on the United States Army Air Corps hyper engine concept, and used a variety of features to produce nearly of engine displacement. However, by the O-1230's entry into service, it had been surpassed by other designs and the investment was not recouped.

Another attempt was made to rescue the design by stacking two O-1230s to make the H engine H-2470 but the only design to use it, the Vultee XP-54, never entered production. The Curtiss XF14C was originally intended to be powered by the H-2470, but the engine's poor performance led to the adoption of an alternative radial engine on the prototype. (The XF14C did not enter production.)

Undeterred by the O-1230/H-2470's failure, Lycoming turned to an even larger design, the 36-cylinder XR-7755, the largest aviation piston engine ever built. This design also experienced problems, and was only ready for use at the very end of World War II, when the aviation world was turning to and turboprop engines to power future large aircraft. There was apparently some interest in using it on the Convair B-36 Peacemaker bomber, but the 28-cylinder Pratt & Whitney R-4360 Wasp Major four-bank radial was used instead.

Through the 1920s and -30s, Lycoming had still been supplying automotive manufacturers with engines. However, these clients each slowly went out of business or switched to Continental engines for their vehicles. By 1931, the company was supplying automotive engines to only three companies: Auburn, Cord and Duesenberg, still all under the control of Cord. These companies closed their doors in 1937, after which Lycoming switched to exclusively designing and producing engines for aviation. In the meantime, the Smith Engineering Corporation, an early manufacturer of controllable pitch propellers had been purchased by Cord and moved to Williamsport.

In 1939 Cord re-organized all of his aviation holdings into the AVCO group, at which point the engine manufacturing company became "AVCO Lycoming". It also leased the government-owned Stratford Army Engine Plant in Stratford, Connecticut, and produced Curtiss-Wright radials under license. After the war, this plant was converted to produce the T53 turboshaft engine, one of its more successful designs. From this point on the piston and turbine engine lines remained separate, with the piston lines being built in the original Williamsport factories, and turbines in Stratford.

By 1961, Lycoming produced 600 to 700 engines per month. Its most successful post-war products were a series of air-cooled Flat-four engine and Flat-six engine general aviation engines. Most famous among these are the O-320 and O-360 four-cylinder engines, and the O-540 six-cylinder engine. "50 Amazing Aircraft Engines," March 15, 2014, Flying, retrieved August 8, 2023Wilson, Tom: 2013 Engine Buyer’s Guide: "Part 1: Traditional powerplants," February 14, 2013, Kitplanes, retrieved August 8, 2023 Many light aircraft are powered by versions of these engines, with power ratings in the range. Engines in this series also include the O-235 four-, O-580 six- and O-720 eight-cylinder engines, and the advanced Turbocharger and fuel injection TIGO-541 variant of the venerable (carbureted) O-540.

In the early 1980s, the general aviation market suddenly diminished and Lycoming's piston engine business was significantly impacted. Attempts were made to move some of the turbine production to Williamsport, but this led to a series of quality control problems and eventually it was abandoned.

Another attempt to rescue Williamsport was made in introducing the "radical" SCORE engine, a Wankel engine originally developed through a joint venture between Curtiss-Wright and John Deere. Curtiss-Wright lost interest in the design just as it was maturing and sold its interests in the project to Deere, which brought in Lycoming to sell the developed engine into the aviation markets. It was guaranteed a startup run by Cessna, also owned by Textron. Just as production was ready to start, Cessna announced it was halting its small-aircraft business for an indefinite period, and SCORE was cancelled. The remains of the Deere licenses were later purchased by Rotary Power International, which briefly produced a version.

Textron purchased the company in 1985. In 1994, Textron sold the Lycoming Turbine Engine Division, located in Stratford, Connecticut, to AlliedSignal, who merged it with the Garrett Engine Division of AlliedSignal as part of AlliedSignal Aerospace, later becoming part of Honeywell Aerospace in 1999.Leyes, p. 725 Textron retained piston engine production in Williamsport.

Lycomings continue to power new light aircraft by fellow Textron division, Cessna Aircraft, "Single-Engine Aircraft" on "Cessna" page, Textron Aviation, retrieved June 29, 2023 and by Piper Aircraft, "Models", Piper Aircraft, retrieved June 29, 2023 Cirrus Aircraft, "Built for Flight Training," Cirrus Aircraft, retrieved June 29, 2023 Diamond Aircraft, "Why Diamond", Diamond Aircraft, retrieved June 29, 2023 and others. Lycomings remain the most popular line of engines for U.S. Experimental / Amateur-Built (E/A-B) aircraft, surpassing the 5 next-most-popular brands, combined.Wanttaja, Ron: "Homebuilt Accidents: Passing the Engine Baton," December 19, 2022, Kitplanes, retrieved June 29, 2023

• A—Aerobatic (dry sump)
• AE—Aerobatic (wet sump)
• E—Electronic
• G—Geared (reduction gear)
• H—Helicopter
• I—Fuel injected
• L—Left hand rotation crankshaft
• M—Designed for unmanned drone
• O—Opposed cylinders
• R—Radial cylinders
• S—Supercharged
• T—Turbocharged
• V—Vertical installation (usually for helicopters)
• X—X engine
• Y—Experimental