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).
Performance issues and modifications on a test car.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan117 | |
| Date | 1st March 1924 | |
| R.R. 403A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} -4- EXPERIMENTAL REPORT. Expl. No. 9680 REF: HAL/101.3.24. ? PII ! Proctor This vibration may be altered when we fix the gearbox on to the engine. We consider it is a point which will have to be overcome before we could deliver any of these cars to customers. On this car, and similarly on the other car which was fitted with the E.A.L. engine, when we apply the foot pedal operating the 4-wheel brakes, we get considerable noise from the engine coupling. We do not get this same noise on a standard 40/50 HP. fitted with similar brakes. The noise is very much less if the clutch is pressed out at the same time as the brakes are applied. The clutch on this car picks up the drive smoothly and sweetly but it does not stop readily. When the oil is hot in the gearbox it does not stop readily as the 20 HP. It may be that the clutch is not floating as well as it should because it takes a longer time for the clutch to stop even when the car is standing and the clutch is depressed. Care was taken when erecting the clutch in order to safeguard against this. Unless Benzol or special fuel is used the engine is bad for detonations especially on magneto ignition. The Magneto is set with the minimum amount of advance for maximum power. We have given the steering maximum lock which is possible to obtain on this car. We have received some further instructions and modifications to steering levers and axle in order to further increase it. The turning circles measured on this car before it went away were as follows :- R.H. 37' L.H. 34.6' The steering has the ball thrust in each pivot. It is lighter than the first car we had with this steering but not as light as the standard 40/50 HP. The road shocks felt on the steering are severe at times. Owing to the fact that the radiator is smaller than the present std. 40/50 HP. we should anticipate that this car may be in trouble with boiling if it is run under hot-weather conditions. The autovac is fitted on the exhaust side. It is possible that under continental conditions this may prove to have insufficient capacity. It was necessary to modify the needle valve in the carburetter in order to pass sufficient A petrol at the low head. contd:- | ||