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).
Issues and performance testing of petrol pump diaphragm assemblies.
| Identifier | ExFiles\Box 149\3\ scan0073 | |
| Date | 10th June 1939 | |
| 1263 To By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}3/JH.10.6.39. PETROL PUMP DIAPHRAGM ASSEMBLIES. The S.U. Co. have changed over to Neoprene diaphragms on their standard pumps and owing to a misunderstanding on their part had failed to order the G5SC material for our requirements. They have now obtained the G.5. material from Germany where it is processed and find that it is too thick to be of any use namely .022 instead of .017" thick. This means that they will be unable to supply us with the G5SC diaphragms for some time, and neither we nor they have any stock left. The only available material is the Neoprene about which we have the following experience - (1) The pump failed when fitted to Lp{Mr Lappin}'s. car, but subsequently ran 400 hours on the Rig when it failed again with worn out rollers. (2) Ran 16,000 miles successfully on B.23.AE. and B.56.BN{W.O. Bentley / Mr Barrington} without trouble. (3) Endurance testing of the Cast Iron H.P. Pump showed that the Neoprene swelled and was compressed onto the rollers causing rapid wear and failure. This was cured by fitting an annular ring between the diaphragm and the pot to give .020" greater clearance and for production in this pump the roller race was deepened by an equal amount to give the same effect. In this state the pump has completed 50,000 miles on 8.B.V. (4) We supplied Neoprene diaphragms for Mr. Burnato's Bentley at his request and responsibility in December 1937 and have heard no more. These were supplied for use with Discol. | ||