Jacobs Aircraft Engine Company

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Jacobs Aircraft Engine Company
IndustryAerospace
FoundedJanuary 1, 1926 (1926-01-01)
FounderAlbert R. Jacobs
DefunctJuly 22, 1957 (1957-07-22)
FateDissolved
Headquarters
Pottstown, Pennsylvania
,
United States
ParentRepublic Industries
(1946–1947, 1950–1956)

The Jacobs Aircraft Engine Company was an American aircraft engine manufacturer that existed from 1926 to 1956.

History[]

Early years[]

The Jacobs Aircraft Engine Company was formed in 1926 in Philadelphia.[1][failed verification] Later the company moved to Pottstown, Pennsylvania[2] after purchasing the machine workshop of the Light Manufacturing and Foundry Company.

Early engines[]

A Cessna Bobcat displayed with a Jacobs L-4 (R-755) engine, Pima Air & Space Museum, 2013

An early product was the 1931 , a 190.4 cu in (3,120 cc) 51 hp (38 kW) three-cylinder air-cooled radial engine. Only 44 were built.

By 1933, Jacobs had developed its most famous engine, the L-4 seven-cylinder air-cooled radial, with a power rating of 225 hp (168 kW) displacement of 757.7 cu in (12,416 cc). It was better known as by its military designation, R-755.[3] At the time it became known as the best producer of engines in the 200-400 horsepower range. Jacobs was the first to start making engines using forged aluminum alloy pistons, sodium-filled exhaust valves, and magnesium alloy crankcases.

The L-4 was used mostly on the Cessna Bobcat, Cessna 195, and Stearman Kaydet.

Due to the tendency of the L-4 engine to vibrate heavily at low rpm, it was given the nicknames Shakin' Jake and Shakey Jake.[4]

Later models[]

Later developments included the 285 hp L-5 or R-830, and 330 hp L-6 or R-915.

Postwar[]

Jacobs was acquired by Republic Industries in 1945, which was in turn acquired by Barium Steel Corporation in 1946. However in 1947, the company was sold back to Albert Jacobs. Jacobs Aircraft Engines went into default in 1950 and was again sold back to Republic.[5] Finally, Barium sold the company in December 1956 and it closed a few months later in 1957.[6][7]

Applications[]

A Pratt & Whitney R-985 engine, produced by Jacobs during World War 2

Jacobs engines were fitted to many US-built aircraft of the inter-war period, including several Waco models. They were in use in 26 different countries including in Canada, where 330 horsepower L6-MB engines were used to power the Royal Canadian Air Force's Avro Anson Mk. II aircraft.[8] In 1941 the American War Department gave the contract to Jacobs to produce Pratt & Whitney R-985 and R-1340 engines until 1945.[8] Jacobs ranked 87th among United States corporations in the value of World War II military production contracts.[9]

Products[]

A sectioned Jacobs L-6, Wings Over the Rockies Air and Space Museum
Model name Configuration Power
R7 140 hp[10]
R7 195 hp[10]
R3 51 hp[10]
Jacobs L-4 R7 225 hp
Jacobs L-5 R7 285 hp
Jacobs L-6 R7 330 hp

See also[]

References[]

  1. ^ "Jacobs R-755-9, Radial 7 Engine". National Air and Space Museum. Smithsonian Institution. Retrieved 17 January 2022.
  2. ^ "Occidental Chemical Corp". E.P.A. Retrieved 2 November 2012.
  3. ^ "Jacobs Aircraft Engine Company aircraft engine specifications". www.pilotfriend.com. Retrieved 2 November 2012.
  4. ^ "The Jacobs Radial Engine". www.gruner.com. Retrieved 2 November 2012.
  5. ^ "Barium Steel Reacquires Firm". Pittsburgh Press. 24 August 1950. p. 35.
  6. ^ "Financial Shorts". Philadelphia Inquirer. 14 December 1956. p. 55.
  7. ^ McCutcheon, Kimble D.; Brown, Robert (19 November 2019). "Jacobs Aircraft Engines". Aircraft Engine Historical Society. Retrieved 10 May 2020.
  8. ^ a b Hoult, Doug. "The Jacobs Engine". www.bombercommandmuseum.ca. Retrieved 2 November 2012.
  9. ^ Peck, Merton J. & Scherer, Frederic M. The Weapons Acquisition Process: An Economic Analysis (1962) Harvard Business School p.619
  10. ^ a b c McCutcheon, Kimble D.; Brown, Robert (19 November 2019). "Jacobs Aircraft Engines". Aircraft Engine Historical Society. Retrieved 2 July 2021.
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