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).
Letter from Ethyl Export Corporation regarding fuel specifications, octane ratings, and valve head design for aero engines.
| Identifier | ExFiles\Box 27a\4\ Scan135 | |
| Date | 16th June 1933 | |
| CABLEGRAMS: ETHYLPORT, LONDON. TELEGRAMS: ETHYLPORT, CHURTON. ETHYL EXPORT CORPORATION Incorporated in the State of Delaware. U.S.A. with limited liability. ABFORD HOUSE, VICTORIA LONDON, S.W.I Telephone: VICTORIA 5520 PERSONAL Head Office: 135 EAST 42ND STREET NEW YORK, U.S.A 16th June, 1933. E.{Mr Elliott - Chief Engineer} W. Hives, Esq., Aero Engine Dept., Rolls Royce Ltd., Nightingale Road, DERBY. Dear Hs.{Lord Ernest Hives - Chair}, With reference to the question of fuel specifications, I have looked into this matter to-day, and I think that the Air Ministry will probably use the C.F.R. (Co-operative Fuel Research) unit when they bring out their new specifications. Therefore, I would in your place, ask for fuels whose Octane values have been ascertained under the conditions which the Ministry will probably lay down for the C.F.R. unit. It is, in our opinion, most unlikely that the Ministry will adopt the 84 Octane fuel and it is almost certain that they will go to 87 for immediate development work. This fuel, 87, will not be up to the standard at present used by the U.S. Army Air Corps, because the proposed Air Ministry fuel test method will be less severe than that which is now in force in the States. Therefore, for your future development, I would advise you to order fuel from the supplying companies in the following manner; "a fuel having an Octane value of 87 when tested in a C.F.R. engine running at 900 r.p.m. with a jacket temperature of 212°F (100°C) and a mixture temperature of 260°F". All the supplying companies can meet these requirements since they have C.F.R. units and you will be fairly sure that any engine company ordering fuel of this knock rating under the above conditions will be certain of obtaining reasonably uniform results from the various oil companies. Please let me know if there is any further assistance I can give you in this matter. I would like to have had a longer talk with you yesterday, but quite realize that this was impossible, and will reserve it until a later date, I think it a good idea to "go the whole hog" on Stellite and I would at the same time suggest a modified design of valve head. That is to say, one having a rim at the valve seat and not too much of a "tulip" form. I think, also, that the seat width could be increased by approximately | ||