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 discussing Phantom III engine oil issues, comparing Castrol XL and Mobiloil Arctic viscosities.
| Identifier | ExFiles\Box 96\1\ scan0405 | |
| Date | 8th October 1939 | |
| 361 WAB/SJC Pen Please answer NS.{Norman Scott} TELEPHONE: SLOANE 9274 "COALITE" CARBONISATION PROCESS TELEGRAMS: "SMOKELESS, PHONE, LONDON." LOW TEMPERATURE CARBONISATION LIMITED. COL. W. A.{Mr Adams} BRISTOW, M.I.E.E., F.R.Ap.S. (CHAIRMAN AND MANAGING DIRECTOR) LYNDON COLIN BAST, M.V.O., R.N. SIR ARTHUR GREY HAZLERIGG, BART. CHARLES HENRY PARKER, J.P., F.C.S. R.{Sir Henry Royce} P. WILSON, C.B.E., M.INST.C.E., M.I.E.E., MEM. CONS.E. Coalite Works, Bolsover, Nr. Chesterfield. 28, GROSVENOR PLACE, LONDON, S.W.1. 8th October 1939. E.W. Hives, Esq., Messrs. Rolls Royce Ltd., Derby. Dear Hives, With the engine of the Phantom III I have always had a good deal of trouble due to the formation of carbon deposit on the plugs and this has given an enormous amount of work as the whole set has had to be sandblasted about every week. I formed the theory that the trouble might be due to the fact that Castrol XL was probably a blended oil and that the fine sludge formation which often occurs with blended oils when heated was carbonising on the plugs. I therefore turned over to the use of Mobiloil Arctic which is a thinner unblended oil, and the trouble has almost entirely vanished. It has, however, been noticed that the oil pressure has gone down and now shows about 25 lbs. instead of 30 lbs. I have tested both viscosities and the Redwood No.1 figures are as follows:- Arctic at 70ºF.{Mr Friese} 660 seconds. Castrol XL " 70ºF.{Mr Friese} 1575 " Arctic at 160ºF.{Mr Friese} 83 seconds. XL " 160ºF.{Mr Friese} 130 " I have taken 160ºF.{Mr Friese} for comparison because this may be somewhere about the maximum working temperature, but you doubtless have the exact figures. It may be that due to the greater fluidity of the oil, more Arctic is passing through the bearings, (or is it) with the consequent fall in pressure? I should like to have your views on this matter before carrying on any further. Yours sincerely, W.A. Bristow | ||