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).
Design error with the twin valve front dampers and proposing modifications.
| Identifier | ExFiles\Box 151\3\ scan0389 | |
| Date | 24th March 1941 | |
| To Ev {Ivan Evernden - coachwork} /JD. {J. Draper - Frames} from Rm {William Robotham - Chief Engineer} /Clm. {D. D. Clapham} 1292 Rm {William Robotham - Chief Engineer} /Clm. {D. D. Clapham} 2/ET.24.3.41. The twin valve front dampers to PL.106 have just been built up and tests indicate an unfortunate design error in the main valve. The length of the valve is such that at least .150" protrudes into the main cylinder bore and is hit by the piston over the last portion of its travel. If it is considered that reducing the length of the valve stem by this much will reduce the length of guide too much, then we would suggest that the valve seat insert be made the guide, and that the cross drillings in the valve stem be altered to suit. Rm {William Robotham - Chief Engineer} /Clm. {D. D. Clapham} | ||