Jacobs Aircraft Engine Company
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The Jacobs Aircraft Engine Company was formed in 1929 in Philadelphia. Later the company moved to Pottstown, Pennsylvania[1] after purchasing the machine workshop of the Light Manufacturing and Foundry Company.
Early engines
An early product was the 1931 L-3, a 190.4 cu in (3,120 cc) 51 hp (38 kW) three-cylinder air-cooled radial engine. Only 44 were built.
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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.[2] 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.[3]
Later models
Later developments included the 285 hp L-5 or R-830, and 330 hp L-6 or R-915.
Applications
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.[4]
In 1941 the American War Department gave the contract to Jacobs to produce Pratt & Whitney R-985 and R-1340 engines until 1945.[4] Jacobs ranked 87th among United States corporations in the value of World War II military production contracts.[5]
After World War II, Jacobs became a division of Republic Industries (not Republic Aircraft).
Products
- Jacobs LA-1
- Jacobs LA-2
- Jacobs L-3 (41⁄8" x 43⁄4")
- Jacobs L-4 (R-755) (51⁄4" x 5")
- Jacobs L-5 (R-830) (51⁄2" x 5")
- Jacobs L-6 (R-915) (51⁄2" x 51⁄2")
References
- ^ "Occidental Chemical Corp". E.P.A. Retrieved 2 November 2012.
- ^ "Jacobs Aircraft Engine Company aircraft engine specifications". www.pilotfriend.com. Retrieved 2 November 2012.
- ^ "The Jacobs Radial Engine". www.gruner.com. Retrieved 2 November 2012.
- ^ a b Hoult, Doug. "The Jacobs Engine". www.bombercommandmuseum.ca. Retrieved 2 November 2012.
- ^ Peck, Merton J. & Scherer, Frederic M. The Weapons Acquisition Process: An Economic Analysis (1962) Harvard Business School p.619