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Allison Engine Company

Allison Engine Company

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The Allison Engine Company was a U.S. aircraft engine
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...

 manufacturer. In 1929, shortly after the death of James Allison
James A. Allison
James Ashbury Allison , born in Marcellus, Michigan, was an American entrepreneur and businessman. He was the inventor of the Allison Perfection Fountain Pen and with Carl G. Fisher a founder of Prest-O-Lite, a manufacturer of automobile headlights. With Carl G. Fisher, Frank H. Wheeler, and Arthur C...

, the company was purchased by the Fisher brothers
Fisher Body
Fisher Body is an automobile coachbuilder founded by the Fisher brothers in 1908 in Detroit, Michigan; it is now an operating division of General Motors Company...

. Fisher sold the company to General Motors, who owned it for most of its history. The company was acquired by Rolls-Royce plc
Rolls-Royce plc
Rolls-Royce Group plc is a global power systems company headquartered in the City of Westminster, London, United Kingdom. It is the world’s second-largest maker of aircraft engines , and also has major businesses in the marine propulsion and energy sectors. Through its defence-related activities...

 in 1995 to become a subsidiary, Rolls-Royce Corporation
Rolls-Royce North America
Rolls-Royce North America, Inc. is a subsidiary of Rolls-Royce plc involved principally in the manufacture of gas turbine engines and other propulsion systems...


Early work

Originally known as the Indianapolis Speedway Team Company, it changed its name numerous times to the Allison Speedway Team Company, the Allison Experimental Company and last as the Allison Engineering Company before becoming a division of General Motors.
Allison started as an engine and car "hot rodding" company servicing the Indianapolis Motor Speedway
Indianapolis Motor Speedway
The Indianapolis Motor Speedway, located in Speedway, Indiana in the United States, is the home of the Indianapolis 500-Mile Race and the Brickyard 400....

 in Indianapolis
Indianapolis is the capital of the U.S. state of Indiana, and the county seat of Marion County, Indiana. As of the 2010 United States Census, the city's population is 839,489. It is by far Indiana's largest city and, as of the 2010 U.S...

. Its only regular production line item was steel-backed lead bushings, used as bearings in various aircraft engines. It also built various drive shafts, extensions and gear chains for high power engines, on demand. Another, smaller, business was the conversion of older Liberty engines to more powerful models, both for aircraft and marine use.

In the late 1920s the United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 funded the development of a series of high-power engines, as part of its hyper engine
Hyper engine
The hyper engine was a 1930s study project by the United States Army Air Corps to develop a high-performance aircraft engine that would be equal to or better than the aircraft and engines then under development in Europe...

 series, which it intended to produce on Continental Motors
Continental Motors Company
Continental Motors Company was an American engine and automobile manufacturer. The company produced engines for various independent manufacturers of automobiles, tractors, and stationary equipment from the 1900s through the 1960s. Continental Motors also produced Continental-branded automobiles in...

' production lines. Allison's manager, N.H. Gilman, decided to experiment with his own high-power cylinder design. Allison's engine became Manufacturer Serial No. 1, AAC S/N 25-521. It was the X-4520, a 12-cylinder air-cooled 4-bank “X” configured engine designed by the Army Air Corps and built by the Allison Engineering Company in 1925. The result was presented to the Army in 1928, which turned down the development proposal.

In 1929, shortly after the death of James Allison
James A. Allison
James Ashbury Allison , born in Marcellus, Michigan, was an American entrepreneur and businessman. He was the inventor of the Allison Perfection Fountain Pen and with Carl G. Fisher a founder of Prest-O-Lite, a manufacturer of automobile headlights. With Carl G. Fisher, Frank H. Wheeler, and Arthur C...

, the company was purchased by the Fisher brothers
Fisher Body
Fisher Body is an automobile coachbuilder founded by the Fisher brothers in 1908 in Detroit, Michigan; it is now an operating division of General Motors Company...

(Leonard), who instructed it to use the cylinder design for a six cylinder engine for a "family aircraft". Before work on this design had progressed very far, Fisher sold the company to General Motors, which ended development due to financial pressures of the Great Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...

. Nevertheless Gilman pressed ahead with the cylinder design, building a "paper project" V-12 engine. The Army was once again uninterested, but instead suggested Allison try selling it to the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

. The Navy agreed to fund development of A and B models to a very limited degree for its airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

s, until the crash of the USS Macon
USS Macon (ZRS-5)
USS Macon was a rigid airship built and operated by the United States Navy for scouting. She served as a "flying aircraft carrier", launching Curtiss F9C Sparrowhawk biplane fighters. In service for less than two years, in 1935 Macon was damaged in a storm and lost off California's Big Sur coast,...

 in 1935, when the Navy's need for a 1000 hp engine disappeared.

The very first V-1710 was purchased by the US Navy as their GV-1710-2, and appears to have had an Allison serial of number 1, suggesting that they restarted numbering for the V-1710. The first V-1710 engine purchased by the USAAC was AAC 33-42, Allison SN 2, the XV-1710-1, while SN’s 3, 4, 5 were V-1710-4 engines for USN airships, followed by a batch of 11 Air Corps engines purchased with FY-1934 funds (34-4 through 34-14) that covered Allison serials 6 through 16. After these the production race was on, totaling over 70,000 V-1710s.


By this point the Army had become more interested in the design, and asked Allison to continue with a new "C" model. They had few funds of their own to invest, and Allison supported much of the development out of their own pocket. The V-1710-C first flew on 14 December 1936 in the Consolidated A-11A testbed. The V-1710-C6 successfully completed the Army 150 hour Type Test on 23 April 1937, at 1,000 hp (750 kW), the first engine of any type to do so. By this point all of the other Army engine projects had been cancelled or withdrawn, leaving the V-1710 as the only modern design available. It was soon found as the primary powerplant of the new generation of United States Army Air Corps
United States Army Air Corps
The United States Army Air Corps was a forerunner of the United States Air Force. Renamed from the Air Service on 2 July 1926, it was part of the United States Army and the predecessor of the United States Army Air Forces , established in 1941...

 (USAAC) fighters, the P-38 Lightning
P-38 Lightning
The Lockheed P-38 Lightning was a World War II American fighter aircraft built by Lockheed. Developed to a United States Army Air Corps requirement, the P-38 had distinctive twin booms and a single, central nacelle containing the cockpit and armament...

, P-39 Airacobra and P-40 Warhawk.

The Army had been leaning heavily towards exhaust-driven turbocharger
A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...

s instead of the more common mechanically-driven supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...

s, feeling that their added performance more than made up for the added complexity. Thus little effort was invested in equipping the V-1710 with a reasonable supercharger, and when placed in aircraft designs like the P-39 or P-40 which lacked the room for a turbo the engine suffered tremendously at higher altitudes. It was for this reason in particular that the V-1710 was later removed from the P-51 Mustang
P-51 Mustang
The North American Aviation P-51 Mustang was an American long-range, single-seat fighter and fighter-bomber used during World War II, the Korean War and in several other conflicts...

 and replaced with the Rolls-Royce Merlin
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...



With the need for the V-1710 winding down at the end of the war, Allison found itself with a massive production infrastructure that was no longer needed. For this reason, in 1947, the Army decided to take General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

's versions of Frank Whittle
Frank Whittle
Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS was a British Royal Air Force engineer officer. He is credited with independently inventing the turbojet engine Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS (1 June 1907 – 9 August 1996) was a British Royal Air...

's jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...

s and give them to Allison to produce instead. The main production model was GE's 4000 lbf (17.8 kN) I-40, produced as the Allison J33. By the time production ended in 1955, Allison had produced over 7,000 J33s.

Allison also took over GE's axial flow engine design, becoming the Allison J35
Allison J35
|-See also:-External links:*...

. The J35 was the primary powerplant for the F-84 Thunderjet
F-84 Thunderjet
The Republic F-84 Thunderjet was an American turbojet fighter-bomber aircraft. Originating as a 1944 United States Army Air Forces proposal for a "day fighter", the F-84 flew in 1946...

 and F-89 Scorpion
F-89 Scorpion
The Northrop F-89 Scorpion was an early American jet-powered fighter designed from the outset as an all-weather interceptor. Though its straight wings limited its performance, it was among the first USAF jet fighters with guided missiles, and notably the first combat aircraft armed with air-to-air...

, as well as appearing on numerous prototype designs. The J35 also finished production in 1955, by which point over 14,000 had been delivered.

Allison also started the development of a series of turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...

 engines for the U.S. Navy, starting with the T38 and a "twinned" version as the T40. The Navy was interested only in the T40, but the complexities of the driveshaft arrangement doomed the engine and the project was eventually cancelled. Allison tried again with the T56, basically an enlarged T38 with the power of the T40, and was eventually rewarded when this engine was selected to power the C-130 Hercules
C-130 Hercules
The Lockheed C-130 Hercules is a four-engine turboprop military transport aircraft designed and built originally by Lockheed, now Lockheed Martin. Capable of using unprepared runways for takeoffs and landings, the C-130 was originally designed as a troop, medical evacuation, and cargo transport...


Over the years a family of engines, based on the T56 basic configuration has been developed, culminating in the T406/Allison AE1107 turboshaft for the V-22 Osprey
V-22 Osprey
The Bell Boeing V-22 Osprey is an American multi-mission, military, tiltrotor aircraft with both a vertical takeoff and landing , and short takeoff and landing capability...

, the Allison AE2100 turboprop, used on newer models of the C-130 and the Allison/Rolls-Royce AE 3007 turbofan which propels many commuter aircraft, such as the Embraer
Embraer S.A. is a Brazilian aerospace conglomerate that produces commercial, military, and executive aircraft and provides aeronautical services....

 ERJ 135 family.

One of Allison's most successful projects is the Model 250 turboshaft/turboprop engine family, which was started by the company in the early 60s, when helicopters started to be powered by turbine, rather than reciprocating, engines.


In the mid-1970s the Allison Division of General Motors Corporation in Detroit designed ceramic components into the Allison GT 404-4 truck engine. Allison continued to work with General Motors on development of ceramic
A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...

A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...

 powered engines until the early 1990s. During their work they were able to engineer fairly stable automobile engines that were capable of burning a variety of fuels including (but not limited to) gasoline, diesel, kerosene, alcohol, vegetable oil, and coal powder.

In the 1980s Allison collaborated with Pratt & Whitney
Pratt & Whitney
Pratt & Whitney is a U.S.-based aerospace manufacturer with global service operations. It is a subsidiary of United Technologies Corporation . Pratt & Whitney's aircraft engines are widely used in both civil aviation and military aviation. Its headquarters are in East Hartford, Connecticut, USA...

 on demonstrating the 578-DX
Pratt & Whitney/Allison 578-DX
-External links:* * , Flight International, June 12, 2007.*...

A propfan was first defined as a small diameter, highly loaded multiple bladed variable pitch propulsor having swept blades with thin advanced airfoil sections, integrated with a nacelle contoured to retard the airflow through the blades thereby reducing compressibility losses and designed to...

. Unlike the competing General Electric GE-36 UDF
General Electric GE-36
-External links:* * , Flight International, June 12, 2007....

, the 578-DX was fairly conventional, having a reduction gearbox between the LP turbine and the propfan blades. Noise considerations, plus a significant reduction in the real cost of aviation fuel, brought the NASA funded program to a halt.

In 1995, Allison tested a prototype lift fan. LiftFan nozzle was tested in 1997 at NASA's Lewis facility.

Acquisition by Rolls-Royce

In 1992 GM tried to sell Allison to concentrate on repairing automobile market share. Rolls-Royce attempted to buy the company in 1993, but GM opted for a management buyout instead for $370 million.

In 1995 authorities approved, with restrictions, that Rolls-Royce bought Allison. for $525 million.


External links