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 use of drilled valves and damper performance for Phantom I and II models.
| Identifier | ExFiles\Box 68\2\ scan0255 | |
| Date | 10th December 1929 | |
| -2- Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}6/M.J.10.12.29.Contd. Though sufficient time has not yet elapsed to verify the point, we appear to have largely overcome the trouble by this means. On Phantom I the drilled valves have for the first time been used to improve low speed riding. As you pointed out, they do not give us something for nothing for the high speed road holding suffers as the leak is increased. We use two .055 holes as the maximum range for curing low speed hashness. Furthermore, except in cases where the owner specifically denies exceeding 50 m.p.h. we only use one .055 hole. No drilled valves are used on Phantom ll at present, they were only contemplated to improve the life of the damper. So farw we have had very little trouble with wear on any of the Phantom ll dampers. The Works find the exterior valve setting a great convenience. We are sure that if the present damper loading could vary with the speed of the car that we should have an almost ideal damping device. We shall have a car running next week with dampers whose loading can be controlled from the driving seat by means of Enot's grease guns acting on the valve springs. This should assist us in determining the range of Automatic Control required. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||