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).
Letter regarding a leaking and underperforming oil filter returned for investigation.
| Identifier | ExFiles\Box 135\3\ scan0237 | |
| Date | 25th February 1938 | |
| 1139 8 Rm{William Robotham - Chief Engineer}/Swd1.6/MH.{M. Huckerby} 25th. February 1938. The AC-Sphinx Sparking Plug Col Ltd., Dunstable, BEDS. Dear Sirs, We are returning an AC. filter for your investigation which is reported to be leaking at the seam in the middle of the body and from mileage figures has not done very well regarding the cleaning of the oil. Commencing with new oil, almost new engine unit and fitted with one of the latest filters received from you a sample taken at 536 miles indicates that the oil is becoming dirty and at 2668 miles dirtier still. We enclose these samples as registered on a piece of blotting paper. As other units fitted with your filters in the same manner are performing better than this particular one we hope that by your examination of the filter in question you will be able to tell us if there is anything wrong. We had anticipated that the oil would not begin to decline in its cleanliness until a mileage of approximately 7,500 or 10,000 had been reached as the latter figure is the one you quote for replenishment of a new filter. The particular unit from which the filter we are returning has been removed, has again been fitted with a new filter and will have some further records shortly. The oil sediment meter which you kindly loaned us some time ago has proved extremely useful in some rig tests | ||