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).
Various engine control mechanisms, including carburation, ignition, and shutters.
| Identifier | ExFiles\Box 41\4\ Scan027 | |
| Date | 12th July 1930 guessed | |
| - 4 - 2. Or a thermostat is used to lock the control device in the normal carburetter setting when engine is warm. 3. 90% of the full working pressure at full throttle is made to set the device in its normal-carburation position. Additional pressure does not produce further weakening of mixture. If this occurred detonation might cause further weakening which would be in the wrong direction. The effect of this control is to run the engine always on the weakest mixture which will give optimum operation. In practice this is said to produce quite remarkable fuel economies on standard cars. It also appears applicable to aero engines, but am asking Mr. Stanton for further information on this. It appears at first that the two pressure samples used for ignition might also be used for carburation control, but evidently if the spark is controlled to keep these samples in balance, they cannot be used for any other purpose. The second (600) sample is slightly preferred for carburation control, as this avoids increasing the volume on the "Retard" side of the ignition control piston. It has been suggested not to use a mechanically operated sampling valve at all but to allow the cylinder pressure to blow out through a spring loaded non-return valve somewhat as used at one time by W'house for their pressure-brakes. This device is not accurate or reliable however, and has been abandoned by W'house. Exhaust Heat. - This is controlled by a butterfly choke valve as on PI in conjunction with carburation, in such a way that same conditions which call for rich mixture also increase heat to carburetter and vice versa. Shutter. - This device it appears might be used to operate the radiator shutter, holding it closed till normal operation (or 90% normal operation) was obtained. It would close when the engine stopped. Yours very truly, Maurice Olley Maurice Olley M | ||