Editing Allison Engine Company (section)

===General Motors===
In 1929, shortly after the death of James Allison, the company was purchased by the Fisher brothers,<ref name="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 owing to financial pressures of the [[Great Depression]]. 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]]. The Navy agreed to fund development of A and B models to a very limited degree for its [[airship]]s, until the crash of the [[USS Macon (ZRS-5)|USS ''Macon'']] in 1935, when the Navy's need for a {{convert|1000|hp|abbr=on}} engine disappeared.

====V-1710====
[[File:Interior view of GMH Allison Overhaul Assembly Plant igloo located on Sandgate Road Albion Brisbane during World War Two.jpg|thumb|GMH Allison Overhaul Assembly Plant in Brisbane during the Second World War]]
[[File:Allison 1710-115 V12 Aircraft engine.jpg|thumb|Allison V-1710-115]]

The very first [[Allison V-1710|V-1710]] was purchased by the U.S. 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 Serial No. 2, the XV-1710-1, while Serial Nos. 3, 4, 5 were V-1710-4 engines for U.S. Navy 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.<ref name="Leonard" />

By this time 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 [[Allison V-1710|V-1710-C]] first flew on 14 December 1936 in the [[Consolidated A-11]]A testbed. The V-1710-C6 completed the Army 150 hour Type Test on 23 April 1937, at 1,000&nbsp;hp (750&nbsp;kW), the first engine of any type to do so. By then all of the other Army engine projects had been cancelled or withdrawn, leaving the V-1710 as the only modern design available.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 power plant of the new generation of [[United States Army Air Corps]] (USAAC) fighters, the [[P-38 Lightning]], [[P-39 Airacobra]] and [[P-40 Warhawk]].

The Army had been leaning heavily towards exhaust-driven [[turbocharger]]s, instead of the more common mechanically driven [[supercharger]]s, favoring the theoretical advantage of using the otherwise wasted energy in the exhaust. Thus, little effort was invested in equipping the V-1710 with a complex two-stage supercharger, and when placed in aircraft designs like the P-39 or P-40, which lacked the room for a turbocharger, 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]] and replaced with the [[Rolls-Royce Merlin]].