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).
Safety fuels, spark injection, carburetters, octane ratings, and nitriding steels for aero engines.
| Identifier | ExFiles\Box 178\2\ img079 | |
| Date | 4th March 1941 | |
| Serial No 4 R Page 3 Pan-American has said it will not buy another plane with an engine burning gasoline, and is going all out for safety fuels with spark injection. It is not believed that safety fuels can be used without injection. Neither is it believed that a diesel which can compete with spark injection will be seen in five years. TWA have at least one plane now running on spark-injection. All three major engine companies are working on it and have engines in the air, as have all experimental fields. Fuel-air ratio can be controlled perfectly with altitude and well enough with throttle opening. Ethyl Corporation has been working on injection tests on spark engines for years. For their purposes ordinary Diesel injectors are good enough, although the plungers score pretty regularly. The engine makers don't use diesel injectors but rather use low pressure injectors. Whether they use Ljungstrom (particulars enclosed) C.F.R. does not know. 5. T.H. spoke of Stromberg "injection" carburetter, illustrated in the Cyclone C200 catalogue recently sent you. Ronald Hazen of Allison told him this varies less than 1% in fuel air ratio in an altitude test up to 20,000 feet, at a given throttle opening. This uses a sampling device of some sort to actually measure pounds of air per minute and proportions the fuel supply under 25 lbs pressure to accurately meet the weight of air per minute. Do you want a carburetter? If so, will see F.C. Mock of Stromberg and get you one. 6. C.F.R. has been doing some further work on measuring anti-knock in an equitable manner, which he said would disappoint some of his English friends and some of the safety fuel men in giving a definitely lower octane rating to the aromatics. I think I have mentioned that there is already a difference between British and American octane ratings whereby 100 octane British is about 94 U.S. 7. T.H. also covered the following minor points:- (a) Will introduce me to members of Alleghany-Ludlum Steel Co., who are now becoming premier makers of nitriding steels in U.S., especially for Wright and Pratt & Whitney. | ||