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 successful testing of special taper valve springs and Mr. Royce's hardening instructions.
| Identifier | ExFiles\Box 80\3\ scan0221 | |
| Date | 22th October 1912 | |
| Ref. Mr R's note on TBB31/WW10912. Re Valve Springs. Members of the T.C. 22/10/12. TBB15/L221012. In reply to a report that the second set of special taper valve springs had run 10,000 miles on the rig without failure Mr Royce writes as follows:- "This would suggest that the proportions are correct, but I understand further tests show want of uniformity. After hardening at lowest possi temperature in cold oil or water let them down in boiling oil or a salt bath until they take a permanent set rather than brake when tested on rig or by an excess of tension. There should be no difficulty of getting them soft enough; we were to do so years ago with a pot of tallow with a gas jet under. Use the chrome steel which ge such good results in road springs when we hardened it. F.H.R." | ||