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).
List of agreed design changes for pump components, including studs, nuts, vent holes, and shrouds.
| Identifier | ExFiles\Box 163\1\ img018 | |
| Date | 7th October 1933 | |
| E.4/HP. 7th October 1933. (9) It is agreed to use six studs and reach nuts instead of the six cheese head screws at present used for the petrol tight joint which has to be made between the body of the pump and the base casting. The studs are 2-BA in size and the two pieces to be held together are fairly rigid so that the conclusion is that the present number of screws or studs is good enough if they can be sufficiently tightened, and it has to be borne in mind that any increase in the number would be very difficult to deal with both from a production point of view and in fouling features of the design. The reach nuts are required just to step out the hexagons of the nuts sufficiently to enable the spanner to clear the large radius in the corner of the pump barrel. (10) It is agreed that the vent hole will be reduced to .062". (11) With regard to the shroud surrounding one of the suction tubes and which shroud was specially introduced with a view to avoiding loss of air from the chamber on the suction side, Messrs. S.U. will make experiments to determine whether this feature is an advantage or not. There is no objection to taking the petrol straight in to a horizontal hole provided it does not increase the loss of air from the chamber aforementioned. (12) It is agreed that the hexagons on the external plugs and unions on the centre casting of the pump should be increased in size and in length where necessary so that they may be tightened more easily without risk of damaging the hexagons. (13) It is agreed that Messrs. S.U. will be at liberty to use their spring wire stop for retaining the delivery valves in their housings in place of the features milled on the retaining nut as this will facilitate production. | ||