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).
Test report on the Auto Klean Oil Filter E.81173, detailing pressure readings for the bypass system.
| Identifier | ExFiles\Box 135\3\ scan0030 | |
| Date | 21th January 1931 | |
| C.O.P.Y. X4037 Rm.{William Robotham - Chief Engineer} AUTO KLEAN OIL FILTER E.81173. 21.1.31. 24-EX. Calculated pressure of oil necessary to lift ball release valve, for by passing the oil in a case when the filter is blocked is 53.5 lbs/sq. in. In order to check the above result the filter was blocked so that all the oil would go through the by pass. An oil gauge was fitted in the filter casing. The needle of the gauge fluctuated badly from 50 - 80 lbs at low speeds. With the governor throttle lever at the top from 80 - 120 lbs. This is due to a high rating spring. 25-EX. Engine and oil cold. The gauge was put in the filter casing of 25-EX. This car has done 4,320 miles since leaving for America. At low speeds the instrument board gauge shewed 24 lbs. where the gauge in the filter shewed 30 lbs. When the governor lever was at the top, the pressure in the filter was 40 lbs/sq. in. I.A. Leslie. | ||