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).
Paper discussing a new high octane blending agent for modern aircraft engines.
| Identifier | ExFiles\Box 150\1\ scan0207 | |
| Date | 29th September 1936 guessed | |
| X1282 38 A NEW HIGH OCTANE BLENDING AGENT H.E. Buc and E.E. Aldrin * Armonde In the modern aircraft engine the increased power output for a given piston displacement has been made possible only by improvement in fuels to permit of higher compression and greater supercharger boost. In 1930 the U.S. Army Air Corps standardized on 80 A.S.T.M. octane number and in 1931 raised this standard to 87 A.S.T.M. octane number. Since 87 octane fuel has been available for the past five years, and since the possibilities of higher octane fuels in permitting greater advances in engine design, output and economy are generally recognized, the obvious question arises as to why the anti-knock value of aviation fuels has taken no definite upward rise during this period. It must be recognized that the attainment of high octane number in a natural fuel, and by high octane is meant a value approaching or exceeding that of pure Iso-Octane, is not only a scientific but an economic problem, considering that sufficient quantities must be in sight for any possible requirement before engines for its proper and exclusive utilization will be generally used. Within limits high octane fuels have been available and used experimentally to demonstrate the advantages of high output engines through the medium of using higher than 3 cc. of Tetraethyl Lead per gallon and more recently through the medium of Technical Iso-Octane which is now available in commercial quantities at a cost which in many cases makes its use profitable. The object of this paper is to describe a new fuel of high anti-knock value apparently suitable in all respects for the modern high output aircraft engine and potentially available in large quantities. There still exists some considerable confusion in regard to evaluating the anti-knock value of aviation fuels in terms of flight performance as related to any single cylinder engine test. The C.F.R. Aviation Gasoline Detonation Sub-Committee is working diligently on this problem and an early acceptable solution is to be desired. In the meantime, many air lines and aircraft engine manufacturers are using A.S.T.M. ratings in specifications; the British Air Ministry in collaboration with the I.P.T. have adopted a slightly modified A.S.T.M. rating to suit British aircraft engines; and in this country the U.S. Army Air Corps have been most active in research activities on high output engines and high octane fuel tests and have developed their own single cylinder test for such fuels. This test involves the use of a modified C.F.R. engine and a large amount of flight experience appears to have justified its use pending further improvements. In the remaining parts of this paper, octane number will be understood to be by the Army test method, unless otherwise designated. Developments in engine design during the past ten years are roughly indicated in Figure 1, taken from a paper presented at the S.A.E. meeting in Detroit in January 1936 by Mr. R.W. Young of the Wright Aeronautical Corporation. Figure 2 from the same paper shows the variation in cylinder head * Standard Oil Development Company | ||