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).
Test report on an automatic gear change and fluid flywheel system, noting temperature, ease of use, and performance under stress.
| Identifier | ExFiles\Box 22\3\ Scan087 | |
| Date | 25th February 1932 | |
| -4- No shutters or thermostatic control of water temp-erature are fitted although provision has been made for a thermostat and shutter control. The average running temperature lies between 57 and 70ºC, but when idling the temperature quickly rises to over 80ºC, due apparently to the very low pump and fan speeds; there does not appear to be any pump circulation at low speeds. Automatic Gear Change and Fluid Flywheel. Gear changing, after a short period required to accustom oneself to the method, is remarkably simple and so far as we have been able to ascertain up to the present, foolproof. One is forced to admit that it is the easiest and most attractive method yet marketed. The fluid flywheel of course makes the gear changes simple and prevents jolting unless used extremely care-lessly. Traffic driving is a condition where the fluid flywheel shows up to advantage; it entirely avoids the necessity for holding out the clutch when pulled up in a traffic queue the only controls used being the brake and accelerator pedal and a very occasional quick depres-sion of the clutch pedal if it is found necessary to change gear. This system of drive must have a large appeal to lady drivers. The fluid flywheel was put through severe tests as follows but in no instance was overheating noticed either by appreciable temperature rise or smell :- The car was stopped on a severe gradient (1 in 5 to 1 in 6) and an attempt made to get away on top gear, the engine ran at full throttle at approx: 600 R.P.M. and the car moved very slowly backwards; this was done for 3 or 4 minutes. Starting on 3rd gear was next tried and in this case the car moved very slowly forwards the engine running at full throttle at a not excessive speed; this was also done for a period of 3 to 4 minutes, and repeated several times. Gear changing was indulged in on the steep gradient by changing from a low to a high gear under conditions where it was impossible for the engine to drive the car forwards in the high gear. The flywheel showed no signs of distress in spite of prolonged misuse of this type. | ||