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).
Secret memo discussing apprehension about the 12 to 1 eccentric ratio on the Spectre silent tappets and experiments on breathers.
| Identifier | ExFiles\Box 4\1\ 01-page275 | |
| Date | 6th March 1935 | |
| To E.{Mr Elliott - Chief Engineer} Secret. L30D Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}9/KW.6.3.35. SpectreCodename for Phantom III. As we mentioned to you on the telephone yesterday, we are somewhat apprehensive about the 12 to 1 eccentric ratio on the SpectreCodename for Phantom III silent tappets. Lately we have had one or two cases where the rocker stuck on the eccentric and held the inlet valve open. This is after running 20,000 miles on 28-EX, and is possibly due to oil getting into a somewhat sludgy condition because up till then we have had no trouble. The fact remains that with the more irreversible 13 to 1 ratio this trouble will be more likely to occur. Another point is that Hancock made some useful experiments on breathers on his last run in France, the details of which we think might with advantage be fitted to the SpectreCodename for Phantom III, and Bentley. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||