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).
Reprint from 'The Automobile Engineer' describing the 'Smith' oil filter with test reports, issued by S. Smith & Sons.
| Identifier | ExFiles\Box 135\3\ scan0111 | |
| Date | 1st January 1936 | |
| indestructible, yet oil in service accumulates impurities. These consist of carbon from decomposition of the oil and extraneous matter such as dust, grit and metal particles. Figs. 9, 10 and 11 are reproductions of untouched photomicrographs of oil samples. Due to the efficiency of the Smith filter, there was nothing to be seen on a photomicrograph. To remove any doubt and to prove this point, the filtered oil photomicrograph, Fig. 11, was taken with the cover glass arranged to blank off a portion of the photomicrograph. The large surface is the filtered oil and the line across is the edge of the cover glass. There is no reason why an oil should not be better after use than unused oil— in fact, the results of the latest research work show that certain lubricating oils do not acquire their full lubricating efficiency until they have been in service for some time under conditions of heating and contact with air. Impurities of all sorts suspended in the oil, however, are always objectionable, and efficiency of purification is obviously of vital importance. It is also suggested that a filtered oil does not take up such a large percentage of volatile matter, and these—since in its use the unstable hydrocarbons of the oil which are the cause of breakdown, and are also particularly responsible for oxidation, are removed while the more stable molecules remain. Further, it is generally agreed by the majority of oil technologists that oil after use and efficiently filtered a number of times is really a super-refined oil. Issued with the compliments of:— S. SMITH & SONS (Motor Accessories) LTD. CRICKLEWOOD LONDON, N.W.2 Printed in Great Britain by The Cornwall Press Ltd., Paris Garden, London, S.E.1. A NEW - - - OIL FILTER A DESCRIPTION OF THE “SMITH” OIL FILTER COMPLETE WITH LABORATORY AND ROAD TEST REPORT. SMITH'S MA Reprinted from “THE AUTOMOBILE ENGINEER,” January, 1936 | ||