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).
Automatic ignition adjustment principle based on cylinder working pressures.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan105 | |
| Date | 28th October 1925 | |
| EFC2/T28.10.25. -3- Contd. points again occurs. In this way, it is contended that the maximum working pressure in the cylinder is maintained at the most generally efficient instant in the stroke for all engine conditions. The argument for the utility of this principle is that the ignition will automatically be adjusted as regards advance and retard, not merely in respect of speed variations, but also in respect of load, mixture, temperature, and altitude variations, whereas the ordinary automatic ignition advance takes speed only into account. The device in principle maintains the equality of the working pressures in the main cylinder at two pre-determined points in the piston stroke, irrespective of the absolute values of these pressures. The power availavle for the operation would appear to be amply sufficient, so that a quite small cylinder can be used. It is very necessary to have the connections between these small cylinder and the main cylinder as short and stout as reasonably convenient to permit of the pressures being suitably transferred. With the tubes too long, oscillations of the gaseous columns will occur and the object will be partially defeated. Mr. Murray stated that they had made a mistake in the first instance of getting the tubes too long. He stated that they are using small poppet valves as the most satisfactory type. I queried whether rotary valves would | ||