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).
Extract from a report on the comparative cold testing of oils.
| Identifier | ExFiles\Box 145\3\ scan0254 | |
| Date | 18th February 1937 | |
| EXTRACT FROM REPORT ON COMPARATIVE COLD TESTS OF OILS. 18/2/37 Finally it was arranged that the car should be an Austin 12/6 straight off the line. We took the precaution of fitting a calibrated starter with brushes already bedded and also new batteries which had been previously cycled three times. The arranged test procedure was as follows and was rigidly adhered to throughout the tests:- The radiator was filled with Bluecol antifreeze mixture. The engine was run until hot and the old oil drained. The sump was then filled with the test oil for flushing purposes and drained after a short run on the road. It was then refilled with the test oil and the final observed road run commenced. The road test was carried out in every case over the same route and efforts were made to drive at approximately the same speed (25 m.p.h.). Water, oil and battery temperatures were taken at the beginning, the turn and the end of the run. A five minutes interval was taken at the turn for taking readings and the same period at the end of the run before taking cranking tests. After taking the hot cranking figures (speed, current consumption, battery and starter volts) the plugs were removed and the "static" and "just moving" torques were taken with a spring balance on the starting handle. A sample of oil was then removed from the sump for dilution and viscosity measurements and the car was allowed to stand a total of 45 minutes before being driven into the cold room. On being driven into the cold room the engine was stopped by switching off the ignition. The battery was given a refresher charge. The car remained in the cold room over-night (16 hours) and in the morning, with the temperatures of oil, water and air at approximately -1°C the usual starter cranking figures were taken; the plugs were then removed for measuring the static and "just moving" torques and finally the engine startability tested. A careful note of the time for the first fire and that necessary to give continuous running was made. The series of tests progressed smoothly and well. The electrical figures obtained checked up very closely in all cases with the calibration and it is believed that the results are thoroughly reliable. The results, as shown later, bear out our theories published in 1935, and in addition have enabled us to gain knowledge of static friction (or breakaway torque) as well as enabling us to obtain full knowledge of the properties of these oils before they are released for service. Results. These are summarised on the separate sheet herewith as far as figures are concerned. Engine details and oil viscosities and densities at the temperatures of the test are collected on a further separate sheet. | ||