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).
Analysis of mineral matter found in oil, detailing its composition and potential sources of contamination.
| Identifier | ExFiles\Box 92\5\ scan0120 | |
| Date | 27th April 1937 | |
| -2- Messrs. Rolls-Royce, Ltd. 27th April, 1937. Analysis of mineral matter:- Silica and insoluble matter 18.3% Copper oxide 35.4% Iron and aluminium oxide 29.2% Zinc oxide 10.1% Lime 4.2% If we consider the mineral matter on an oil free basis you will observe that it is approximately 14%, which is unusually high. This mineral matter contains 22.5% of road dust, which is revealed by the silica and the lime content. This figure is also high. You will observe the large amount of copper and zinc in the deposit. Why these should be present, particularly in comparatively large amounts, is not very obvious. If the temperature has been high, then of course there is the possibility that there has been a reaction between Castrol Hi-Press and some copper alloy or copper in the axle assembly. This evidence seems to suggest intrusion of road dust, and elevated temperature, both of which have played their part. The oil contains 0.53% of material insoluble in petroleum ether (b.p. under 40). From bench tests at 110°C the maximum amount of insoluble matter produced has been 0.2%, and at 120°C about 0.3%, even after 270 hours. Yours faithfully, C. C. WAKEFIELD & Co., LIMITED. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} Evans CHIEF CHEMIST | ||