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 necessity and specifications for an inlet fuel filter, comparing materials and practices.
| Identifier | ExFiles\Box 135\2\ scan0037 | |
| Date | 4th March 1921 | |
| Oy3 - G 4321 Mar.4.21 Mr. Claude Johnson - Sheet 2 ing through the filter, and in any case the jet of petrol would tend to throw any dirt to the bottom of the filter. We do not think that an inlet filter is necessary for the States, since Mr. Caswell, during the war, found that in most cases the gauze of both inlet and delivery filters was corroded away after a few months and yet no trouble occurred unless water or bits of the filter itself got washed into the jets. Most American makers do not use an inlet filter, and members of our own organization who have used cars for years, say that wherever they have found an inlet filter on their cars, they have taken it off without trouble resulting. The gasoline obtained from pumping stations is likely to be free from dirt, whereas when cans are used, dirt and flakes of paint are liable to enter the tank. Where American makers use an inlet gauze, it is usually a coarse mesh strainer of about 40 to the inch, to keep large dirt from entering. We can obtain Monel Metal gauze of 120 to the inch, equally divided vertically and horizontally, with wire about 5 thousandths diameter, at the same price as the Greening gauze, and are debating using this on car 101 onwards of Series 20. Meanwhile, we are drilling holes through the brass frame at the top of the filter, on our cars 1 to 100, and are doing the same on imported chassis, since this appears to be the only way of making the existing gauze suitable. We are also running the demonstration car without an inlet filter to see whether any trouble ensues. We should suggest that Derby make a similar test, and should appreciate information as soon as possible as to whether they consider that we can omit the inlet filter on Series 21. Yours truly, ROLLS-ROYCE OF AMERICA, Inc. Per M.{Mr Moon / Mr Moore} Olley MO/G | ||