Diese geniale Motormodifikation des Ingenieurs machte die F4U Corsair unaufhaltsam!
Video from the channel The Engine Archives about Vought F4U Corsair, linked on its Above Ten Thousand entry. Duration: 23:50. Language: English. Video type: Documentary.
What it's about
The documentary is about Leonard S. "Luke" Hobbs, a Pratt & Whitney engineer, and about the improvements made to the fuel system of the R-2800 Double Wasp engine fitted to the Vought F4U Corsair. It first sets out the problem with float carburetors: they starved the engine of fuel in inverted flight or under negative G. It then covers the solutions: the pressure carburetor, water-methanol injection and the evolution of the engine's variants.
Historical context
Hobbs was born in 1896 in Carbon County, Wyoming. From 1920 he worked as a test engineer at McCook Field (Dayton). He later moved to Stromberg, where he devised a twin-bowl float carburetor that worked in inverted flight. He joined Pratt & Whitney in 1927. He became chief engineer in 1935, and from 1939 he led all of the company's engineering. In 1944 he was promoted to vice president of engineering at United Aircraft. He oversaw the J57 turbojet, which earned him the 1952 Collier Trophy. He retired in 1958 and died in 1977. The video also recalls that British Spitfires suffered the same fault. Beatrice Shilling eased it with a disc that restricted the fuel flow.
Key facts
The R-2800 had 18 cylinders in two rows of nine. It first ran in 1937 and produced 2,000 hp. The pressure carburetor grew out of a Bendix concept that Hobbs' team refined: it replaced the float with diaphragms and springs and worked in any attitude. Water-methanol injection cooled the mixture and prevented detonation. The R-2800-8W produced 2,250 hp for takeoff and 2,450 hp in emergency power for about five minutes, thanks to a tank of roughly 15 gallons. Corsairs with this engine reached the front in late 1943. The video cites Ken Walsh, of VMF-124, with 21 victories, and Gregory "Pappy" Boyington, of VMF-214. The R-2800-18W carried a two-stage supercharger and let the F4U-4 reach 448 mph at 26,200 feet. With the R-2800-32W, which produced 2,760 hp in emergency power, the F4U-5 reached 462 mph. More than 125,000 R-2800 engines were built, which also powered the P-47, the F6F, the B-26, the A-26 and the P-61.