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 the Vacuum Oil Company regarding the mixture of Mobiloil and Castrol, and enclosing friction test results for Clearosol engine oils.
| Identifier | ExFiles\Box 145\1\ scan0155 | |
| Date | 17th February 1936 | |
| Y56-32137 No. 2. V.O.Co., Ltd., to Rolls-Royce Limited, Derby. With regard to the mixture of Mobiloil "EP{G. Eric Platford - Chief Quality Engineer}" with Castrol Hi-Press, there should be no undesirable action whatever. We understand that you are interested in the possibility of using light bodied engine oils like Mobiloil Arctic, and we are therefore attaching figures for the whole series of Clearosol Mobiloil engine oils which were tested recently at the National Physical Laboratory. The two columns under each grade refer to the physical readings before the friction test, and the corresponding readings after 50 hours in the friction testing machine. These tests were carried out on the Jakeman journal friction testing machine with which you may be familiar. However, we are enclosing herewith copy of our booklet "Slum-Free", as the test procedure is described briefly on pages 12 and 13 in this. As a matter of interest, the figures for seizing temperature and coefficient of friction of each grade are very good in their respective viscosity classes. Naturally, this test is not an exact reproduction of conditions in an engine bearing because the rate of oil feed in the test machine is constant, whereas in an engine, the oil of lower viscosity will pass through the bearing in greater quantities than will the oil of higher viscosity. However, we should welcome an opportunity of discussing these results with you at some convenient time. Yours faithfully, VACUUM OIL COMPANY LIMITED Chief Engineer. AD/AH [Stamp Text] BIF 1936 BIRMINGHAM ENGINEERING AND HARDWARE SECTION 17-28 FEBRUARY SEE OUR EXHIBIT | ||