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).
Resolving a noisy petrol pump, slow engine running, and silencer issues.
| Identifier | ExFiles\Box 130\2\ scan0020 | |
| Date | 3rd July 1936 | |
| COPY. To Rm.{William Robotham - Chief Engineer} Cricklewood, July 3rd, 1936. We have tackled a customer's complaint of noisy petrol pump and are pleased to say we have made a 100% silent pump in the driver's seat. In this case, one unit of the pump was making a metallic noise whilst the other was dead quiet. To cut out all we did, we found that the noise was due to the hard hitting of the armature spigot on to the face of the papier-mache washers. By fitting an extra paper washer to soften the blow, a quiet action was obtained. The reason for this is the allowance made in the manufacture. It is quite probable that the spigot in question has an allowance in length which in one case when the armature is pulled in the movement is not sufficient to cause a heavy contact; in the other case the limit may be such that a harder blow is received. Setting of the diaphragm does not alter it to any degree. We had not the time to investigate the possibility of varying lengths of the aforesaid spigot, as the owner required the car, but I have asked Dixon to try and obtain data at Kingsbury. Another fault we found was that the pump was fouling the collar of the steering column. The pump action could be felt through the steering wheel. We have made a further improvement in the mounting of the pump by fitting a laminated rubber mounting. We removed the hard bakelite washers and fitted three layers of the sample rubber herewith. This cleared the column and assisted in quietening the action of the pump and it could be fitted to all existing cars without much cost, and is good. Slow Running of the 25/30 HP. We cannot obtain good results and the owners are not satisfied. Spitting in the Silencer. This can only be overcome by strengthening the slow speed jet which affects idling. It was bad on GUL-43. It is suggested that it could be overcome if we removed our front expansion chamber of the exhaust. Could this be confirmed ? Hs{Lord Ernest Hives - Chair}/G.W.Hancock. | ||