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).
Mr. Royce's wishes for modifications to the air pump delivery valve on chassis 49 GB.
| Identifier | WestWitteringFiles\C\September1919\ Scan15 | |
| Date | 9th September 1919 | |
| To DA.{Bernard Day - Chassis Design} from E.{Mr Elliott - Chief Engineer} Copy to Sd. " " DH.{D. Henderson - Showroom} " " EH. " " EPC. ORIGINAL. E1/019/9/19. 2 RE 49 GB - AIR PUMP. X 2631 Referring to the air pump fitted to chassis 49 GB, we have disassembled and inspected the parts of the delivery valve, and the following points should have attention in accordance with MR. Royce's wishes:- (1) The air valve spring is much too long, and gives too heavy a pressure. 49 GB spring was cut in half and half only put back into the pump. The pressure even then was thought to be too strong. It is considered undesirable to have a spring which extends to a great length when free. (2) Make the valve spring engage with an undercut on the valve, so that it will be possible to lift out the valve by means of the spring. (3) The washer on the valve cap is not spigoted and can be eccentric. The valve cap should either be made with a taper undercut or should have no undercut, and the thread formed by milling with counterbore in pump. E.{Mr Elliott - Chief Engineer} | ||