1/30/2024 0 Comments Recordit v0.2The drive might be a "long-nose" or close coupled propeller reduction gear, an extension drive to a remote gearbox, or a gearbox that could drive two wing-mounted propellers from a fuselage-mounted engine. The front of the engine could have one of a number of different output drives. The accessory end had a one- or two-speed engine-driven supercharger that might have a second stage with or without an intercooler, the ignition magnetos and the customary assortment of oil and fuel pumps, all dictated by the application requirements. Aircraft such as the P-38, P-40, P-51A, and North American P-82E used close-coupled propeller reduction gears, a feature of the V-1710-F series. The P-39, P-63, and Douglas XB-42 Mixmaster used V-1710-Es, exchanging the integral reduction gear for an extension shaft driving a remotely located reduction gear and propeller. A turbo-supercharger could be used, if desired. The engine was constructed around a basic power section, from which different installation requirements could be met by fitting the appropriate accessories section at the rear, and an appropriate power output drive at the front. The engine design benefited from the General Motors philosophy of built-in production and installation versatility, embracing a philosophy of modular design for aviation powerplants. Versatility and reversibility of rotation The valvetrain has a single overhead camshaft per bank of cylinders and four valves per cylinder. The V-1710 has 12 cylinders with a bore and stroke of 5.5 by 6 in (139.7 by 152.4 mm) in 60° V format, for a displacement of 1,710.6 cu in (28.032 L), with a compression ratio of 6.65:1. When war material procurement agents from the United Kingdom asked North American Aviation to build the P-40 under license, NAA instead proposed their own improved aircraft design, using the V-1710 in their NA-73. All entrants in the new pursuit competition were designed around it, powering the Lockheed P-38, Bell P-39 and Curtiss P-40. The engine was then offered to aircraft manufacturers where it powered the prototype Curtiss XP-37s. The V-1710-C6 successfully completed the USAAC 150 hour Type Test on April 23, 1937, at 1,000 hp (750 kW), the first engine of any type to do so. The Great Depression slowed development, and it was not until December 14, 1936, that the engine next flew in the Consolidated XA-11A testbed. The USAAC purchased its first V-1710 in December 1932. The United States Navy (USN) hoped to use the V-1710 in its rigid airships Akron and Macon, but both were equipped with German-built Maybach VL-2 engines as the V-1710 was still in testing when the Macon was lost in February 1935 (the Akron having been lost in April 1933). To ease production, the new design could be equipped with different propeller gearing systems and superchargers, allowing a single production line to build engines for various fighters and bombers. The Allison Division of General Motors began developing an ethylene glycol-cooled engine in 1929 to meet a USAAC need for a modern, 1,000 hp (750 kW), engine to fit into a new generation of streamlined bombers and fighters. The V-1710 nevertheless gave excellent service when turbocharged, notably in the P-38 Lightning, which accounted for much of the extensive production run. When smaller-dimensioned or lower-cost versions of the V-1710 were desired, they generally had poor performance at higher altitudes. The United States Army Air Corps (USAAC) preference for turbochargers early in the V-1710's development program meant that less effort was spent on developing suitable mechanically driven centrifugal superchargers for the Allison V-12 design, as other V-12 designs from friendly nations like the British Rolls-Royce Merlin were already using. Versions with a turbocharger gave excellent performance at high altitude in the twin-engined Lockheed P-38 Lightning, and turbo-superchargers were fitted to experimental single-engined fighters with similar results. The Allison V-1710 aircraft engine designed and produced by the Allison Engine Company was the only US-developed V-12 liquid-cooled engine to see service during World War II. Aircraft engine produced and manufactured by Allison Engine CompanyĪn early Allison V-1710 engine (V-1710-7)
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |