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).
Conclusions from tests on Wraith valve timing, recommending erring on the side of late timing.
| Identifier | ExFiles\Box 10\3\ 03-page187 | |
| Date | 7th October 1938 | |
| To RHC.{R. H. Coverley - Production Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. RHC{R. H. Coverley - Production Engineer}/PVT. c. LA.{L. A. Archer} 654. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}4/MH.{M. Huckerby}7.10.38. WRAITH VALVE TIMING. We have carried out a number of tests concerning the power with various valve timings and have come to the following conclusion. Any discrepancies in timing relative to the official timing diagram LW.1415 which are bound to arise should definitely err on the late side and not early, for example, it is better to have a timing 4° or 5° late than 1° or 2° early. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||