Ranger V-770

The Ranger V-770 was an American air-cooled inverted V-12 aero-engine developed by the Ranger Aircraft Engine Division of the Fairchild Engine & Aircraft Corporation in the early 1930s.

Design and development
In 1931, the V-770 design was put to paper, based on the Ranger 6-440 series of inverted inline air-cooled engines, and test flown in the Vought XSO2U-1 Scout. In 1938 it was tested in the Curtiss SO3C Seamew and found to be unreliable with a tendency to overheat in low-speed flight. By 1941 a more developed V-770 was installed in the Fairchild XAT-14 Gunner prototype and found satisfactory for the production Fairchild AT-21 Gunner gunnery school aircraft.

Produced from 1941 to 1945, the V-770 featured a two-piece aluminum alloy crankcase, steel barreled cylinders with integral aluminum alloy fins and aluminum alloy heads. The V-770 was the only American inverted V12-type inline air-cooled engine to reach production. The engine was used in a relatively small number of Army Air Forces aircraft, among them the Fairchild AT-21 twin-engine trainer of which approximately 175 were built, and in the two Bell XP-77s.

Variants

 * V-770-4: Installed in the Vought XSO2U-1 Scout
 * V-770-6: Installed in the XAT-14 Gunner prototype, intended for the Ryan SOR-1 Scout
 * V-770-7: Installed in the Bell XP-77 light-weight fighter prototype
 * V-770-8: Installed in the Curtiss SO3C Seamew Scout.
 * V-770-9: Installed in the XAT-6E Texan prototype.
 * V-770-11: Installed in the Fairchild AT-21 Gunner.
 * V-770-15: Installed in the Fairchild AT-21 Gunner.
 * SGV-770C-1: Tested in the Curtiss XF6C-7 Hawk Fighter-Bomber at 350 hp.
 * SGV-770D-5: Developed for post-war commercial use, 700 hp (kW) at 3,600 RPM, weight 870 lb (395 kg), height 31.11 in (790 mm), length 74.92 in (1,900 mm), width 33.28 in (846 mm)

Applications

 * Bell XP-77
 * Curtiss SO3C
 * Edo OSE
 * Fairchild AT-21
 * Fairchild BQ-3
 * Ikarus 214D
 * Vought XSO2U

Survivors

 * Carolinas Aviation Museum 1 restored engine in storage
 * Myers Aviation, Inc. Oshkosh, WI 2 engines in storage