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).
Requesting the production of experimental Wraith tappet guides to test using the crankcase material directly.
| Identifier | ExFiles\Box 10\3\ 03-page055 | |
| Date | 24th August 1937 | |
| To HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. Hl. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}8/AP.24.8.37 WRAITH TAPPET GUIDES. Will you please produce a set of tappet guide bushes in the same material as the crankcase (RR.50) and to be given the identical heat treatment that the crankcase is normally subjected to. This experiment is important and determines whether it will be possible to delete the bushes and use the actual crankcase as the guide for the bottom tappets. The above to be made to EW.859 with the bore inclined at 45' with the exception of the material, as previously stated to be in RR.50. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} + 654? | ||