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).
Pump noise issues and diaphragm material for 25/30 and Phantom III models.
| Identifier | ExFiles\Box 149\4\ scan0059 | |
| Date | 28th October 1936 guessed | |
| -2- Some agreement will have to be reached as to how the cost is to be met. We recommend that all 25/30's and Phantom III already delivered should be dealt with as opportunity occurs via G.W.H. Referring to the noise question we have just completed experiments in silencing the pumps that are approved of by S.U.'s. It consists of a small machining operation and fitting a velumoid washer on the top of the solenoid. The worst that can happen is that the washer can collapse and the pump become noisy again. We recommend that this modification should be brought in on 25/30 and Ph.III pumps as as soon as possible without upsetting production. That both modifications should be fitted immediately to all company's cars to gain experience. The pumps in the frame we are urging as far as possible and have put in hand a further two dozen. It is, however, a serious departure from standard S.U. practice and we shall only have our own experience to go on so that we cannot jump too rapidly. Probably however it will only be necessary to change continental cars if the two proposed immediate modifications are successful. It is hardly correct to say that we are much behind S.U.'s other customers with pump material. The original G.3. diaphragms submitted to us eighteen months ago had definite defects and were not comparable to the fabric that Skinner is recommending today. The first were fitted on production 12 months ago but only on small production Rileys, Jaguar, Wolsley, and M.G.'s. Morris did not change until Jan. of this year. The fabric has given satisfaction in service but is more susceptible to discol than our present standard, also probably slightly more likely to leak. However a leak does not cause the customer to walk home. Up till Jan., Morris was using the Gut diaphragm which was our standard until 12 months ago, they were not overwhelmed with trouble, is fact only 2 to 3% complaints. Rm.{William Robotham - Chief Engineer} | ||