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).
Possible alterations to address Spectre tappet wear.
| Identifier | ExFiles\Box 96\2\ scan0027 | |
| Date | 23th February 1935 | |
| Test [Stamped] x384 [Handwritten] E/PSN.2/MN.23/2/35. Copy to Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Room A C Smith [Handwritten signature] SPECTRECodename for Phantom III TAPPET WEAR. Once we are convinced that this wear is occurring under normal conditions then a simple line of attack is that of trying different materials or surface conditions for the rubbing parts. There are a number of possible alterations:- 1. We understand that a considerable increase in hardness can be obtained above that which is at present being used, by variation of the conditions in the cloudburst process. 2. The tappet might be made in a low carbon steel such as UBA which we understand will take a considerably harder case than the 5% nickel steel we are at present using. There would also be the added advantage of dissimilar materials for the two rubbing surfaces. 3. The rubbing face on the tappet could be 'Stellited'. 4. Either the camshaft or the tappets could be chromium plated. Messrs. Fescol claim to have a process of plating which gives better adhesion between the chromium and the steel than the normal process, and should trouble be experienced with the plate flaking off, their process might be of assistance in preventing this. E/PSN P- [Handwritten initials] | ||