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).
Proposed improvements to valve springs, carburetter, air pump, undershield and brakes.
| Identifier | Morton\M3.3\ img004 | |
| Date | 15th February 1917 guessed | |
| -4- It is desirable to fit strong valve springs, like those on 49-GB, the advantage of these are that the valves follow the cams when cold and the oil is sticky on the stems. Further with the light valves and these strong spring which it is arranged to fit, the valves do not leave the cams up to a much higher speed, and therefore, there is less danger of broken valve springs. In lightening the valves it is proposed that we retain the cotter pattern, so as to be interchangeable with the present ones. Regarding the carburetter I have suggested a slower moving air valve to avoid the weakness on opening the throttle. Regarding the induction pipe it may be found that a higher gas speed may increase the ramming effect, and therefore give better power and possibly better distribution, and is of course more economical in weight and fitting, and should be therefore adopted if no loss of power is experienced. Air Pump. Owing to the fitting of electrical self starter, the air pump will be on the governor case and no relief valve will be fitted. Some improvements can be made to the undershield towards the front and where they do not give entire satisfaction. Brakes. In addition to the aluminium strap for the outer foot brake, I am proposing to use ferodo for the side brakes, and since the side brake lever can follow up the expansion differently to the foot brake, I feel sure that this will be found desirable. It will effect a slight saving of weight, Cont'd | ||