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).
Modifications and performance tests of the R.R. petrol pump.
| Identifier | WestWitteringFiles\W\September1931-November1931\ Scan058 | |
| Date | 29th October 1931 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. SG.{Arthur F. Sidgreaves - MD} s. WGT. E.{Mr Elliott - Chief Engineer} c. Dn. IV. ORIGINAL. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}7/AD29.10.31. x7460. x2677 R.R. PETROL PUMP. We attach curves showing how the delivery of the R.R. petrol pump varies with different sizes of reservoir on the suction side, and also the difference between an air reservoir and a petrol reservoir. It will be seen that with an 8 cc air bottle we are able to supply the requirements of the P.2. engine. It will be noted that the condition of this pump for these tests was not standard, as in the process of trying to improve this delivery we altered various parts such as the size of valve ports and passages and the stops for the valves. Having established, however, the big difference which the reservoir makes, we are in the process of going back over the job and finding out which of the previous modifications we made are of any value. At the moment we think that apart from the reservoir, the most useful modification was increasing the spring loads so that the top spring gave a delivery pressure which was on a par with the A.C. and the return spring was sufficiently strong to make the push rod approximately follow the cam. The new design of petrol pump which you have already sent us, of course overcomes this difficulty of having to have a very heavy bottom spring. We hope that when we actually get the petrol pump working in conjunction with the carburetter on the engine we shall find that we can work with a weaker delivery spring than at present and so overcome the trouble of float chamber flooding which Hancock experienced in France with the A.C. petrol pump. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||