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 dispatch and testing procedure for improved filter cartridges and replacement valve springs.
| Identifier | ExFiles\Box 108\1\ scan0053 | |
| Date | 4th August 1937 | |
| 600a also 300a To Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} (Chateauroux) from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}1/AP.4.8.37 32-HX. We are sending out 2 filter cartridges which are an improved type as received from America, in response to the P.S. of your memo Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux}6/JAB.15.7.37. for a spare cartridge. They are marked by the number 4 on the top face. As you will by now have received the 'CW' oil, we presume that you have changed from the 'XL' which you only used as a temporary measure, by virtue of not having any 'CW'. From this point, we should like the test to be carried out in the originally discussed manner in order to obtain definite data regarding the efficiency of these filters. Commencing with new oil and new cartridge, take a sample phial of oil at each 1000 miles. When the oil appears to be getting very dirty, fit a new cartridge and note whether by the samples taken at intervals of 1000 miles the condition of the oil is improving. If there is no recovery in the condition of the oil then the filter is subjected to the wrong pressure or is not of sufficient capacity for the engine. Refilling as you did with new oil at 6,640 miles and fitting a new cartridge gave no clue as to what the element was capable of. 26.G.Vl.{V. Lewis / Mr Valentine} During our holidays some replacement valve springs to RS.{Sir Henry Royce's Secretary}540 were sent out in view of the failure of No.7. spring. We trust that you only changed the one that failed. Together with the filter cartridge, we are sending 6 springs which we want you to fit in case of failure of the existing springs. These have a slightly modified coiling at the base but otherwise are the same as the Rs.{Sir Henry Royce's Secretary}540 springs in 'Swedish wire'. The latter to be used in case of failure and not the ones as sent during the holidays. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||