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).
Reliability of valve springs after changing the material from Chrome Vanadium to Carbon Wire.
| Identifier | ExFiles\Box 158\5\ scan0054 | |
| Date | 24th January 1940 | |
| 1360 To By.{R.W. Bailey - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} c. to Oy. Rm.{William Robotham - Chief Engineer}9/JH.24.1.40. re Valve Springs. With reference to Ey.2/HR.23.1.40. As you know we changed from Chrome Vanadium to Carbon Wire valve springs about 2 years ago. Our results in service and experimentally indicate that we have lost no reliability at all by the change, in fact, we have had less failures with the carbon wire than with the Chrome Vanadium. This of course is not conclusive evidence since the change of material only applies to one particular design of valve spring. We have recollections of breaking 12 Chrome Vanadium valve springs during a trip to America, and having no trouble with the carbon wire springs produced by Barnes Raymond & Gibson in Detroit. Rm.{William Robotham - Chief Engineer} | ||