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).
Schedule of alterations for the 20 HP carburetter as requested by Mr. Royce.
| Identifier | ExFiles\Box 5\4\ 04-page145 | |
| Date | 12th August 1925 | |
| To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to CJ. Hs.{Lord Ernest Hives - Chair} X5080 E1/M12. 8. 25. 20 HP. CARBURETTER. E.5080 X.4228 Please find attached a schedule of alterations which Mr. Royce wishes to incorporate in the 20 HP. carburetter. The reason or object of each alteration is given in the schedule. SCHEDULE OF ALTERATIONS TO 20 HP. CARBURETTER. (1) Make a lighter air valve in aluminium of EAC. pattern so that the air valve will lift earlier and thus reduce the prolonged period of over richness at present existing. (2) Make carb. and float chamber bodies in alum. to save weight and expense. (3) Restore the dia. of the throttle valve to 1.5" so as to effectively drain the spray chamber of liquid fuel. (4) The throttle valve spindle bushes to be pressed into position up to a jig so that they will be correctly placed to give running clearance with a flat on each side of the throttle disc of the same width as the bush. (5) The choke tubes to be lengthened within the spray chamber so that all excess liquid fuel drains in towards the throttle valve, and not down the choke tubes. (6) Retain air valve spring in cover by a reduced coil calmping screw and nut so that it will not fall out. (7) Test a diffuser jet with pool in the high speed throat with a view to better atomisation, and to quickly replacing the fuel in the induction pipe after a starvation period of full throttle work. SEE ORIGINAL FOR SKETCHES. E.{Mr Elliott - Chief Engineer} | ||