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).
Investigations into noise issues on the 20 HP model, focusing on rear dampers and linkages.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan039 | |
| Date | 18th January 1929 guessed | |
| contd :- -4- the rear of the 20 HP. on certain cars which act as good 'sound boxes'. These cars have been rather troublesome because, not knowing the exact source of the noise, we only were able to silence them temporarily with new dampers. For a permanent solution, the lines we are working on are :- 1. Reduced side play in links. (Road and bench endurance tests to ascertain if time to become noisy is reduced.) 2. Improved lubrication of links by oil holes. 3. Better links in nitro steel. 4. Body mounting investigations. (Difficult because of distributed coachbuilders. Subframe would go far to solve.) In addition we think that a drilled or slotted high pressure valve, if this was carried out in moderation, would not spoil the road holding of the car (confirmed by America) and would help noise troubles. Rather a common source of noise is poor adjustment of the ball ends on the connecting links. If lubrication is neglected wear produces the same result. Spring loaded ball ends at this point would conform with our practice elsewhere on the car, and prevent the damper being blamed unfairly. It will be noted from the 20 HP. 14-G-4 10,000 miles report that no excessive damper wear is reported. This body is subframe mounted and therefore will not be sensitive to shock absorber noise. We are expecting the rear dampers to do more and more as the max. speed of our cars increases. They already work at almost twice the pressure of the front ones. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||