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 regarding the testing and recommendation of new motor oil grades.
| Identifier | ExFiles\Box 145\3\ scan0243 | |
| Date | 28th May 1937 | |
| CONTINUATION SHEET No. 1. FROM SHELL-MEX AND B.P. LIMITED. TO. W. A.{Mr Adams} Robotham, Esq., DATE. 28th May 1937. to Motor Manufacturers so that they may form their opinions as to which of the new Shell grades should substitute those they recommend at present. In a number of cases I have arranged with the firms concerned to supply us with a new engine which is built up from the raw on the oil specified, run in on the bench, stripped and examined, re-built and run up to full power, and then installed in a chassis. We acquire the completed cars and they are run under observation by my own staff for at least ten thousand miles, after which an engine strip is made at maker's works and conditions noted and comparisons made. Careful measurements, in co-operation with makers, are made of cylinder bores, journals etc. at all strips, and periodical analyses are made of the oils during running. This is the only practical way I have been able to devise of testing motor oils, it seems to be acceptable to most manufacturers and very few of them seem inclined to make oil tests for themselves. As your Company's standards are so much higher than are those of others I expect that you will wish to carry out tests of your own before you will agree to any change in the Shell motor oil grades, viz. Single Shell - Winter, AeroShell - Summer, mentioned in your present Rolls and Bentley Instruction Manuals. Our new oils have very much better low temperature viscosities than the old ones, and we have carried out a series of tests in Jos. Lucas cold chamber at Birmingham (which equipment they kindly lent us for the work) which prove the oils highly satisfactory in this respect. Viscosity indices also are excellent, of the order of 100 and better, high temperature conditions are, therefore, fully satisfied, and, since the solvent extraction process gives a very stable product, cleanliness in operation is assured. Our suggestion to you will be that our new Single Shell and Triple Shell should be recommended in place of current Single and AeroShell. I attach figures appertaining to them which may be of interest, and we shall be glad to let you have any quantity of the oils you may require for test purposes. We realise that oil testing is a lengthy, and probably inconvenient, matter for you and we are reluctant to | ||