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 Shell-Mex and B.P. Ltd detailing the octane rating test results of Shell Benzole and B.P. Ethyl Benzole mixtures.
| Identifier | ExFiles\Box 27a\4\ Scan325 | |
| Date | 30th July 1934 | |
| SHELL-MEX AND B.P. LTD Distributors for the Shell and Anglo-Persian Oil Groups Telephone: Temple Bar 1234 Telegrams: Shelbeepee, Rand, London, Telex P.O. BOX NO. 148 SHELL-MEX HOUSE VICTORIA EMBANKMENT . LONDON . W.C.2 Your Reference ......................... Our Department T & R.{Sir Henry Royce} LGC/LD. Date 30th July 1934. W. A.{Mr Adams} Robotham, Esq., Messrs. Rolls-Royce Ltd., Experimental Department, DERBY. Dear Mr. Robotham, In reply to your letter of July 25th, I write to say that we have now carried out tests with the 50/50 Shell Benzole and B.P. Ethyl Benzole Mixtures, and the respective O.N. ratings by the C.F.R. Motor Method show the Shell Benzole to be 79.5 O.N. and the B.P. Ethyl Benzole 81.5. O.N. There is thus very little difference, and I think you will agree that when we consider that the comparatively high mixture temperature (300°F) used with the Motor Method certainly derates Benzole as compared with its road performance and probably flatters lead, that the O.N. ratings of the two mixtures are identical for practical purposes. I also think it worth while mentioning that if these two fuels had been tested in the C.F.R. engine by the Aviation Method (260°F Mixture Temperature) that the O.N. ratings would have been probably two or three numbers higher. We have to-day received your official order No 67898 for 50 gallons "BP" Ethyl-Benzole mixture, and I am wondering if this, in view of your letter to me All offers subject to acceptance by return of post unless otherwise stated | ||