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).
Pressure type oil filter and carburettor float chamber filter on the Wraith model.
| Identifier | ExFiles\Box 6\6\ 06-page238 | |
| Date | 25th June 1937 | |
| E.{Mr Elliott - Chief Engineer} from Rm.{William Robotham - Chief Engineer} c. to Ey. W R A I T H.{Arthur M. Hanbury - Head Complaints} There are two points on the Wraith to which we should like to draw your attention:- (1) PRESSURE TYPE OIL FILTER. We believe that you were convinced by the information obtained in America that the pressure type oil filter has now been rendered obsolete by the very excellent and cheap by-pass filters now on the market. We feel that the Wraith should start life with a by-pass filter. (2) It is almost universal practice to carry the float chamber filter on the union to the carburetter. The present arrangement of Wraith filter on the induction pipe is not easy to dismantle, and seems to us to be extravagant. Also the induction pipe gets exceedingly hot after the car has been standing a very short time, which will aggravate vapour lock. Since we have shown this filter is big enough for the P.III, the size could obviously be reduced for the Wraith, which should permit making a neat assembly on a banjo intake to the carburetter. The banjo dimensions will, of course, have to be generous to avoid restriction. Another feature in connection with the filter in this position is that we have several times run into trouble with the P.III due to dirt collecting on the float chamber side of the filter when the car has been pulled up, and the subsequent flooding has been very irritating. Rm.{William Robotham - Chief Engineer} | ||