The Ranger V-770 was an American air-cooled inverted V-12 aircraft engine developed by the Ranger Aircraft Engine Division of the Fairchild Engine & Aircraft Corporation in the early 1930s.
7-793: In 1931, the V-770 design was built, derived from 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 but was found to be unreliable with a tendency to overheat in low-speed flight, but would still be the most produced aircraft to have the V-770, with 795 being built. Its competitor Vought XSO2U also suffered from overheating problems that were never satisfactorily solved. By 1941
14-570: A more developed V-770 was installed in the Fairchild XAT-14 Gunner prototype gunnery school aircraft, which went into limited production as the Fairchild AT-21 Gunner , of which 174 were built, not including one radial engine prototype. Produced from 1941 to 1945, the V-770 featured a two-piece aluminum alloy crankcase, steel cylinder barrels with integral aluminum alloy fins and aluminum alloy heads. The V-770
21-564: The Ranger Aircraft Engine Division of the Fairchild Engine and Airplane Corporation of Farmingdale, New York , United States. The engine was mainly produced for Fairchild's family of training aircraft in the mid-1930s. According to H.L. Puckett, "Ranger developed a system of air cooling all cylinders to a high degree of uniformity. The system employed air under pressure, admitted through an opening in
28-462: The front of the engine cowling. The air traveled through the tunnel from the air scoop. The tunnel, with one side fitted with corrugations, directed the air against the cylinders at relatively equal pressure and volume. Baffles between the cylinders directed the air past machined cooling fins around the cylinder barrels and heads. This gave remarkably balanced temperature range in level flight..." The Chromoly crankshaft with moveable counterweights on
35-422: The hollow journal and thence through tubes in the crankchecks to hollow crank pins." The crankcase is made of aluminum alloy. Ranger manufactured the cylinder barrels from rough alloy steel forgings, while the pistons were machined from aluminum alloy castings, and the connecting rods were machined from chromoly steel forgings. The alloy steel forging camshaft was bolted to the cylinder heads, and driven by
42-402: The rear to control torsional vibration. According to Puckett, "All main journals and crankpins are hollow for lightness and so that they may serve as oil reservoirs. Oil passages from the main bearings to the connecting rod bearings are drilled in each crankcheck so that each rod bearing is fed by two oil passages. The crankshaft is drilled so that excess oil from the main bearings is forced into
49-502: Was the only American inverted V-12 air-cooled engine to reach production. The engine was used in very few aircraft, among them the short lived Fairchild AT-21 twin-engine bomber trainer, and in the two Bell XP-77 light-weight fighter prototypes. Data from Janes Fighting Aircraft of World War II (1989). Comparable engines Related lists Ranger L-440 The Ranger L-440 (company designation 6-440C ) are six-cylinder inline inverted air-cooled aero-engines produced by
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