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).
Comparison report on the performance of Tecalemit and Autoklean oil filters following a 10,000-mile test.
| Identifier | ExFiles\Box 135\3\ scan0054 | |
| Date | 14th October 1932 | |
| Y4057 From Hs{Lord Ernest Hives - Chair}/CWH. By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} HS{Lord Ernest Hives - Chair}/CWH.8/KT.14.10.32. x7190 x7941 Re. Oil Filters. We fitted a Tecalemit Oil Filter on 19-EX for the 10,000 miles test in France to observe whether the filter soon became choked or had any effect upon the oil pressure. Two pressure gauges were fitted, one giving the oil pressure entering the filter, the other giving the pressure after leaving the filter. The difference in pressure upon starting up the engine in a morning did not vary more than 1 lb. and when the oil became hot no difference in pressure was noted. This remained consistent for 8,000 miles. During the latter 2,000 miles the oil pressure leaving the filter dropped approx. 4 lbs. when cold and approx. 1 lb. when hot, showing that the filter was becoming choked. We should say that the filter would require cleaning in service every 8,000 miles. We examined and removed the filter after 10,000 miles; it was covered with a thick oil deposit. Since then we have left it to drain, and after the surplus had drained away, there was a fair amount of tar looking substance left on the felt. We could also observe fine particles of white metal embedded in the filter. Taking a comparison of the Tecalemit filter and the Autoklean filter, we should say that the Tecalemit filter had collected 25% more sludge and foreign matter than the Autoklean, during similar test. The points for the Tecalemit filter are - (1) No moving parts. (2) Could be mounted at the side of the engine. (3) Felt star filter could be cheaply replaced. Against the filter - (1) Bulky in size. Points for the Autoklean filter. (1) Should give an indefinite life. (2) Can be easily cleaned. | ||