Lycoming Engines

For other uses, see Lycoming.

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Lycoming Engines is a major aircraft engine company, known primarily for its smaller general aviation engines. For most of its history Lycoming has been part of the AVCO group as AVCO Lycoming. In 1987 AVCO was purchased by Textron to become Textron Lycoming. In 2002 the company was renamed Lycoming Engines.

History

Lycoming first set up business in 1888 in Williamsport, Pa (in Lycoming County, whence the name) as a sewing machine manufacturer, and soon branched out into bicycle manufacturing as well. Through the early post-World War I era, the company increasingly focused on automobile engines, and at one time became a major supplier for Auburn, which produced the Auburn, Cord, and Duesenberg lines. Eventually Lycoming became their major supplier, and in 1929 Errett Lobban Cord bought the company, placing it under his Auburn Manufacturing umbrella group. Also in 1929 Lycoming produced its first aviation engine, the R-680 radial. This was a fairly successful design, and was used widely in light aircraft, including Cord's Travel Air.

Through the 1930s Lycoming made a number of efforts to break into the "big league" with high-power engine designs. The 1200 hp O-1230 was its attempt to produce an engine based on the USAAC's hyper engine concept, which used a variety of features to produce one horsepower per cubic inch (46 kW/L) of engine displacement. However, the O-1230 took so long to reach service, it had been bypassed 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 2300 hp (1,700 kW) H engine H-2470, but the only design to use it, the P-54, never entered production.

Not to be stopped by the O-1230/H-2470's failure, they turned to an even larger design, the R-7755, the largest aviation piston engine ever built. However, this design ran into problems, and was only ready for use at the very end of World War II, when the aviation world was turning to jet engines for power on future large designs. There was apparently some interest in using it on the B-36 Peacemaker 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 a government-owned 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.

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 fours, and the O-540 six. The majority of light aircraft today are powered by a version of these engines, covering everything from the 100 to 360 hp (75 to 270 kW). Other engines in the series include the O-320 four, O-580 six and O-720 eight, 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 bottom dropped out of the general aviation market, and Lycoming's piston engine business suddenly disappeared. Attempts were made to move some of the turbine production to Williamsport, but this led to a series of quality control problems and eventually the attempt was abandoned.

Another attempt to rescue Williamsport was made in an attempt to introduce 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 exiting the small-aircraft business, and SCORE was cancelled. The remains of the Deere licenses were later purchased by Rotary Power International, who briefly produced a 340hp version.

Textron purchase

Textron purchased the company in 1986, spinning off the turbine division to AlliedSignal in 1996.

Engines

Piston engines

• Lycoming R-680, 9-cylinder radial, 220 to 295 hp, Lycoming's first engine

• Lycoming O-145, 2-cylinder
• Lycoming O-235, 4-cylinder, 108 to 118 hp, introduced in 1940 and still produced, widely used on the Cessna 152 and similar GA designs
• Lycoming O-290, 4-cylinder, 125 hp, 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 to 160 hp
• 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 O-390, 4-cylinder, introduced in 2002, a smaller version of the new 580

• Lycoming O-435, 6-cylinder, 185 to 260 hp, also developed as a tank engine
• Lycoming O-480, 6-cylinder
• Lycoming O-540, 6-cylinder, 260 to 315 hp, widely used on the Piper Navajo, Comanche, etc.
• Lycoming O-541, 6-cylinder, improved 540, featuring turbocharging on all models
• Lycoming O-580, 6-cylinder, 330 hp, aerobatic engine introduced in 1998

• Lycoming O-580, 8-cylinder, original "580", produced from 1948 to 1961
• Lycoming O-720, 8-cylinder, basically a scaled up version of the 360/540

Turbine engines

• Lycoming T53, turboshaft, 600 hp, used on the Bell UH-1 "Huey" and others
• Lycoming T55, turboshaft, 3,750 hp, used on the CH-47 Chinook
• Lycoming ALF 502, turbofan, based on the T55 turboshaft, used on the BAe 146 and Bombardier Challenger 600.

External links

• Textron Lycoming - Official Homepage
• Lycoming engines - an extensive list of every version of Lycoming's general aviation engines
• Lycoming - lists all major engine series

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This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lycoming Engines".