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).
The benefits of a new oil refining process, named the Clearosol process, for improving engine cleanliness and oil stability.
| Identifier | ExFiles\Box 145\2\ scan0056 | |
| Date | 1st February 1935 guessed | |
| No. 2. 1 operation at high temperatures. The internal cleanliness of engines is thus remarkably improved, even after long usage. The use of excessive quantities of sulphuric acid during oil refining is thereby eliminated with corresponding advantages in the properties of resulting lubricants. Deleterious matter is removed by this process to an extent not previously possible in oils produced in commercial quantities. The resulting benefits secured are: unusually flat viscosity curves, much reduced rate of oxidation, and virtual elimination of the sludge and gummy deposits. It will be appreciated that this represents a basically sound improvement in methods of oil refining. It should not be confused with methods designed to reduce the rate of oxidation of oils by the addition of various substances. This particular method of attempting to reduce the rate of oxidation in oils, as it is purely one of addition, does not have any effect, beneficial or otherwise, on the viscosity curve of the oil. The essential difference between the Clearosol method of treatment and the addition of substances is that, in the Clearosol method of refining, the deleterious readily oxidised constituents of the oil are removed, whereas, in the other method, an attempt is made to counteract these deleterious substances by the addition of other substance or substances. Sludge Formation Minimised. Reduced sludging, due to improved oil stability, results from the new process because it has not hitherto been possible to remove, by conventional methods of oil refining, those constituents of lubricating oils which oxidise relatively quickly, and, therefore, accentuate the rate of sludge formation in crankcases, or set up "gummy" deposits on valve stems. The Clearosol Process does this most effectively, as the lubricant in the engine develops impurities due to oil oxidation at a very much slower rate, lubricating conditions are markedly improved, and the dangers of choked oilways in crankshafts, dirty oil filters or screens, sludge deposits in oil sumps, etc., are substantially reduced. It is a fact that, with these oils in use for extended periods, engine crankcases strip down in remarkably clean internal condition. Colour of Oil. The new oils are paler in colour than the former grades of Mobiloil, and the visible result of the Clearosol solvent ex- | ||