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 discussing the properties and knock rating of Koolmotor fuel.
| Identifier | ExFiles\Box 27a\4\ Scan111 | |
| Date | 5th May 1933 | |
| CABLEGRAMS: ETHYLPORT, LONDON. X1282. TELEGRAMS: ETHYLPORT, CHURTON. ETHYL EXPORT CORPORATION Incorporated in the State of Delaware, U.S.A. with limited liability. ABFORD HOUSE, VICTORIA LONDON, S.W.1 Telephone: VICTORIA 5520 PERSONAL Head Office: 135 EAST 42ND STREET NEW YORK, U.S.A 5th May, 1933. W. A.{Mr Adams} Robotham Esq., Rolls-Royce Ltd., DERBY. Dear Rm.{William Robotham - Chief Engineer}, Very many thanks for yours of the 3rd May and with reference to the run in your production I am of course not saying anything about it and regard any such trip as entirely unofficial. Referring to your last paragraph on the subject of Koolmotor. The average knock rating of two or three samples which have been collected in this area is about 76.5 on the Series 30 engine. Some people have been quoting 80 Octane, but this figure has generally been obtained on an Armstrong engine which always reads at least 4 numbers too high. From all the information we have, we do not think it is correct that this fuel is made up from Californian spirit, and in fact I have seen some analyses which show the spirit to be of the "cracked" variety. They seem to sell more of the alcohol blend in the South of England and that around the North generally has little or no alcohol in it, but is composed mostly of "cracked" spirit. It does not evade the usual water separation troubles common to alcohol fuels and in fact, one or two cases of trouble have come to our notice. To sum up, I would say that the knock rating of this fuel varies very considerably, anything from about 70 to 77 Octane, and separation trouble are likely to occur if it is left lying about for any length of time. All the best, Yours sincerely, [Signature] | ||