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 asking for information on the performance of a by-pass oil filter, including cartridge replacement mileage and efficiency.
| Identifier | ExFiles\Box 135\3\ scan0161 | |
| Date | 5th August 1937 guessed | |
| -2- We are now proceeding on the following lines; commencing with clean oil and new cartridge, a sample of oil to be taken every 1000 miles. When the oil appears to be getting dirty a new cartridge to be fitted to see if any recovery in the condition of the oil takes place. The filter which ran the 5000 miles has been returned to us and we wonder what method you use to estimate the amount of dirt that has been taken from the oil.? In conjunction with the above we give below a list of some of the points we should like to know:- (1) At what mileage would you expect to have to fit a new filter cartridge running under our conditions.? (2) If the filter be operating efficiently should not the oil retain its original amber colour.? (3) Is our 'set up' of your filter in its most efficient form.? We are anxious to make this type of bye pass filter a success and would appreciate any information you can give us in this respect. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||