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).
Suggested modifications to the S.U. Twin Petrol Pump, covering electrical connections, valves, and seatings.
| Identifier | ExFiles\Box 27a\2\ Scan251 | |
| Date | 26th September 1933 | |
| Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} X2677 To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Bwg.{J. C. Bowring} Hs{Lord Ernest Hives - Chair}/Bwg.{J. C. Bowring}1/KT.26.9.33. S.U. TWIN PETROL PUMP. Electrical Connections Etc. It was suggested to the S.U. Co. that the conductor which at present is clamped under a bolt head against the base plate should be threaded through a hole drilled up the centre of the bolt, and soldered in. As this will mean dissembling the base plate again to make the necessary joint, after the pump has been built up, they suggest that we have flexible conductors fitted with Ross Courtney type terminals, instead of the present rigid conductors. This modification should prove satisfactory and we cannot see why this should not be done. .. It has been agreed that insulated terminal knobs be fitted to the outside of the pump. With reference to the pumps being coupled through the ignition switch and the possibility of pump failure causing a short through the ignition system, it is suggested that a fuse be incorporated in each pump. A question arose as to the amperage of the fuse used on the ignition side, and as the latter was not definitely known, no decision was made re this; however, they are writing us on one or two points and will bring the matter up in their letter. Valves, Seatings & General Mechanism. It was found that, on comparing the R.R. seatings with the S.U. seatings, ours are twice the width of theirs - i.e. S.U. .031", R.R. .062" - and it was agreed that we should have .031 seatings in future. These will not only be more efficient, but will reduce the tendency for foreign matter to become lodged under the valves. It was also suggested that we continue to use the brass valves as they are quite efficient with a .031" seating. A further suggestion was made with regard to the delivery valve stops, that is, that the stop seating be raised another .015" and brought to a knife edge finish; this would obviate any valve sticking and also would cause less restriction to the petrol flow. | ||