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).
Intended modification to lighten the P.II. exhaust valves and questioning its effectiveness.
| Identifier | ExFiles\Box 131\4\ scan0334 | |
| Date | 29th June 1937 | |
| W/K.{Mr Kilner} To Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} 1113 Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}5/AP.29.6.37 P.II. Exhaust Valves. With regard to your intended modification to lighten the latest type of P.II. exhaust valve, we are not quite sure from the information you gave us how this could make the valve gear any quieter. There would seem to be only two possible explanations. Firstly, the fit of the valve in the guide is as on a new car. Secondly, you may have fitted a lighter valve spring in conjunction with a lighter valve. We are asking you these questions because there is a certain amount of resistance here to lightening the exhaust valve because, you will remember, the reason for its present size was to overcome failures with the last type of camshaft. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||