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).
Letter detailing the reasons for choosing electrical petrol pumps and instructions for testing.
| Identifier | ExFiles\Box 82\1\ scan0174 | |
| Date | 5th August 1933 | |
| Yv53a G.W.Hancock, Hotel de France, Chateauroux, Indre, FRANCE. From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}2/KT.5.8.33. Thank you for your reports on petrol pumps. We have decided to go for the electrical petrol pumps. The reasons for this decision are as follows :- (1) This pump will prime the carburetter when starting from cold without the necessity for running the battery down. (2) When the car is stopped after a long blind, the electrical pump will clear the vapour lock which takes place far more quickly than the mechanical pump because again, its rate of working is independent of the starter motor. (3) It delivers a constant head of petrol to the carburetter at a much lower pressure than the mechanical pump. (4) If one pump fails it is still possible to get home on the second pump. (5) Spares will be far more easily obtained than if the pump was an R.R. product. (6) The pump can be put in a cool place and need not be bolted to the crankcase. We have today despatched two of these pumps to you. These have been running a continuous endurance test in the Electrical Laboratory for three or four weeks. This test included running dry for 120 hrs. which is a very strenuous overload. Therefore, do not criticise these pumps too much. Two more pumps will follow next week, but the S.U. Company are at present shut down and therefore the pumps we are sending are the only two we can obtain. We want you to find out the best place to fit the pumps on the chassis. We do not want them to be put in an inaccessible position, unless this is found necessary in order to avoid vapour lock. From the point of view of noise we feel that you may like to mount them on a bracket off the frame. | ||