From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
American aircraft engine developments, including notes on Allison's V-12 and 'W' 24-cylinder engines.
| Identifier | ExFiles\Box 27\3\ Scan211 | |
| Date | 15th May 1939 guessed | |
| 5. efforts, but they were annoyed also by the action of General Motors in showing at the World's Fair the Allison "W" 24-cylinder engine which was supposed to be very much on the secret list, and about which the air-cooled manufacturers knew very little. These actions led to the air-cooled people obtaining permission for the Army to show their 2000 HP. engines in the Aviation Building. Points of notable interest are the development of dynamic suspension for radial engines and the advantages claimed for dynamic balancing of crankshafts. While American air-cooled engined are noteworthy for their high quality and durability they are heavy, and our British engines are held in very high esteem by American engineers. As far as could be gathered their good opinion was on account of our high performance and very low weight. American type test requirements are much more stringent than ours, and Engine Companies carry out much more developing testing than we are in a position to do. In spite of this, however, quite serious troubles will be dealt with under different headings in the Component Section. Allison Engineering Corporation No visit was paid to this firm, but some information was gleaned in conversation with engineers. The V-12 liquid-cooled engine has 1710 ci.ins. displacement, and is rated at 1000 HP. 2600.RPM. take-off on 87 Octane fuel. It weighs 1280 lbs., bore and stroke 5½" x 6". We heard in many quarters that the engine was producing 1200 HP. on 100 Octane fuel. The bare weight of the engine is about 200 lbs less than that of '1380' Twin Wasp, but complete with coolant, and radiator the installation weighs 600 lbs more. As already stated the Allison "W" 24-cylinder engine was shwon by General Motors at the World's Fair. The engine consists of two V-12 engines geared together with an angle of about 30° between adjacent banks of cylinders, so that the other banks are each 15° above the horizontal. This results in an | ||