|Founder(s)||Madame Ellen Curtis Demorest|
Lycoming is a major US manufacturer of civilian aircraft engines. Headquartered in Williamsport, Pennsylvania, Lycoming produces a line of horizontally opposed, air-cooled, four-, six- and eight-cylinder engines available including the only FAA-certified aerobatic and helicopter piston engines on the market. The company has built more than 325,000 piston aircraft engines and powers more than half the world's general aviation fleet, both rotary and fixed wing. The company is currently part of Textron's Avco Corporation.
Sewing machines, bicycles and fashion 
Lycoming claims to have been founded in 1845 by "Madame Ellen Curtis Demorest", however, the early history of the company (especially prior to 1860) is unclear. (Biographer Ishbel Ross notes that the marriage of Ellen Louise Curtis to William Jennings Demorest took place in 1858, somewhat later than the purported date of establishment of the company.) In New York, New York, between c. 1860 and 1887, the Demorests published fashion magazines and operated the Demorest Fashion and Sewing-Machine Company (sometimes known as the Demorest Manufacturing Company) producing "Madame Demorest" and "Bartlett & Demorest" sewing machines and selling Ellen Demorest's innovative paper patterns for dressmaking. During this period, Ellen Demorest patented several fashion accessories, while her husband patented improvements to sewing machines and an apparatus for the vulcanization of rubber.
Around 1883, Gerrit S. Scofield & Frank M. Scofield (advertising agents from New York) bought the Demorest brand and the sewing machine business (the Demorests retained the magazine business), and constructed a factory in Williamsport, Pennsylvania (in Lycoming County). At the urging of the newly-established Williamsport Board of Trade, citizens invested US$100 000 into the new manufacturing facility, which employed 250. The factory produced 50 to 60 sewing machines per day, and the company sold them for between US$19.50 and US$55.00 each. With the development of the "New York Bicycle" in 1891 (designed by employee S. H. Ellis), the company diversified its product offerings. Until the early 1900s, the factory produced sewing machines, bicycles, typewriters, opera chairs and other products.
Engine manufacture 
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By 1907, the manufacture of sewing machines had become unprofitable for Demorest, and the company was sold and restructured as the Lycoming Foundry and Machine Company, shifting its focus toward automobile engine manufacture. In 1910, the company supplied its first automobile engine to Velie, and during the early post-World-War-I era, the company was a major supplier to Auburn (which produced the Auburn, Cord, and Duesenberg lines). 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 a L-Head straight 8 of 298.5 cu. in. displacement which produced 125 h.p. 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. 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 1 200 hp (895 kW) O-1230 was Lycoming's attempt to produce an engine based on the USAAC's hyper engine concept, and used a variety of features to produce nearly 1 hp/in3 (46 kW/L) of engine displacement. However, by the O-1230's entry into service, it had been surpassed by other designs and the US$500 000 investment was not recouped. Another attempt was made to rescue the design by stacking two O-1230s to make the 2 300 hp (1 700 kW) H engine H-2470 but the only design to use it, the P-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 R-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 jet engines to power future large aircraft. There was apparently some interest in using it on the Convair B-36 bomber, but the Pratt & Whitney R-4360 was used instead.
In 1939 Cord re-organized all of his aviation holdings into the AVCO group, at which point the engine manufacturing company became "AVCO Lycoming". They also leased the government-owned Stratford Army Engine Plant in Stratford, Connecticut and produced Wright radials under license. After the war, this plant was converted to produce the T53 turboshaft engine, one of their 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 600-700 engines per month. Their most successful post-war products were a series of air-cooled flat-4 and flat-6 general aviation engines. Most famous among these are the O-235 and O-360 four-cylinder engines, and the O-540 six-cylinder engine. Many light aircraft are powered by versions of these engines, with power ratings in the 100–360 hp (75–270 kW) range. Engines in this series also include the O-320 four-, O-580 six- and O-720 eight-cylinder engines, and the advanced turbocharged and fuel-injected 450 hp (340 kW) 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 in a partnership between Curtiss-Wright and John Deere. Curtiss-Wright lost interest in the design just as it was maturing and sold it to Deere, who brought in Lycoming to sell into the aviation markets. They were guaranteed a startup run by Cessna, also owned by Textron. Just as production was ready to start, Cessna announced they were halting their 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 340 hp (254 kW) version.
Textron purchased the company in 1986. 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. Textron retained piston engine production in Williamsport.
The aircraft piston engine prefixes are:.
- AE—Aerobatic (wet sump)[clarification needed]
- H—Horizontal Helicopter
- I—Fuel Injected
- L—Left Hand Rotation Crankshaft
- O—Opposed Cylinders
- G—Geared (reduction gear)
- V—Vertical installation for helicopters
Piston engines 
- Lycoming R-680, 9-cylinder radial, 1929, 220–295 hp (164–220 kW), Lycoming's first engine (4.625 inch diameter x 4.5 inch stroke x 9 cyls = 680.41 in3)
- Lycoming O-145, 4-cylinder, 1938, (3.625x3.5=144.49/2.37 L)
- Lycoming IO-233-LSA, 4-cylinder, 100–116 hp (75–87 kW), announced 2008 (probable certification in 2009
- Lycoming O-235, 4-cylinder, 108–118 hp (81–88 kW), introduced in 1940 and still produced, widely used on the Cessna 152 and similar GA designs
- Lycoming O-290, 4-cylinder, 125 hp (93 kW), downsized version of the 435 introduced in 1942 and largely ignored for aviation use, but widely used in ground-power carts sold to the US military
- Lycoming O-320, 4-cylinder, 150–160 hp (112–119 kW), used on Cessna 172
- Lycoming O-340, 4-cylinder
- Lycoming O-360, 4-cylinder, introduced in 1955 and widely used ever since, formed the basis for the 540 and 720
- Lycoming TIO-360-EXP, 4-cylinder, 180 hp (134 kW), announced 2008, non-certified turbocharged engine for homebuilding use
- Lycoming IO-390, 4-cylinder, 210 hp (157 kW), announced (probable certification in late 2008)
- Lycoming O-435, 6-cylinder, 185–260 hp (137–194 kW), also developed as a tank engine
- Lycoming O-480, 6-cylinder
- Lycoming O-540, 6-cylinder, 230–350 hp (172–261 kW), widely used on the Piper Navajo, Comanche, etc.
- Lycoming TIO-541, 6-cylinder, improved 540, featuring turbocharging on all models
- Lycoming IO-580, 6-cylinder, 300 hp (223 kW), engine introduced in 1997
- Lycoming GSO-580, 8-cylinder, original "580", produced from 1948 to 1961
- Lycoming IO-720, 8-cylinder, 400 hp (298 kW) engine introduced in 1961
- Lycoming O-1230
- Lycoming H-2470
- Lycoming XR-7755, 36-cylinder multibank liquid-cooled engine, largest aircraft piston engine ever built
Turbine engines 
- Lycoming T53, turboshaft, 600 hp (447 kW), used on the Bell UH-1 "Huey" and others.
- Lycoming T53-L 13 845 kW (1,133 hp) used on the DB Class 210 locomotive
- Lycoming T55, turboshaft, 3 750 hp (2 796 kW), used on the CH-47 Chinook.
- Lycoming PLF1, the first high-bypass turbofan designed in the US; not produced
- Lycoming LTS101/LPT101, turboshaft and turboprop
- Lycoming ALF 502, turbofan, based on the T55 turboshaft, used on the BAe 146 and Bombardier Challenger 600.
- Lycoming AGT1500, turboshaft, 1 500 hp (1 119 kW), used on the M1 Abrams.
- Lycoming TF-40 marine gas turbine for the USN's LCAC hovercraft.
- "Our History". Lycoming Engines. 2008. Retrieved 2008-12-30.
- Kelly (November 2006). "Demorest Sewing Machine Company History". kelsew.info. Retrieved 2008-12-30.
- US 87648, Demorest, E. L. & W. G. Cook, "Brace and Suspender Combined", published 1869-03-05
- US 264935, Demorest, E. L., "Puff for Head-Dresses", published 1882-03-09
- US 23948, Roberts, Edward A. L. & William J. Demorest, "Apparatus for Vulcanizing Rubber"
- US RE 1444, Roberts, Edward A. L. & William J. Demorest, "Improvement in Apparatus for Vulcanizing Rubber, &c."
- "Names Obtained by Fraud.". New York Times. 1888-11-04. p. 9. ISSN 0362-4331. Retrieved 2008-12-30.
- Kevin McQuown. "Lycoming County's Old Days". Williamsport Area High School Website. Williamsport Area School District. Retrieved 2008-12-30.[dead link]
- "The Lycoming Museum" (PDF). Lycoming Engines. 2008. Retrieved 2008-12-30.
- Richard Bach (December 1961). "Lycomings Piston Engines". Flying Magazine.
- Leyes, p. 725
- Lycoming (2004). "360 Series" (PDF). Retrieved 2008-09-16.
- "Aerobatic engines" (PDF). Retrieved 2011-03-19.
- Flying (magazine), Vol. 135 Issue 11, Nov. 2008, p. 37, "Lycoming Powers Up at AirVenture
General references 
- Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN 0-7509-4479-X.
- Leyes II, Richard A.; William A. Fleming (1999). "10". The History of North American Small Gas Turbine Aircraft Engines. Washington, DC: Smithsonian Institution. p. 725. ISBN 1-56347-332-1.