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).
Effects of different choke sizes on a Phantom II single carburetter.
| Identifier | ExFiles\Box 13\3\ 03-page349 | |
| Date | 9th October 1931 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wer. c. Da.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. Iv. x7080. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/AD9.10.31. x3603. We send herewith curves indicating the effect of various choke sizes used in a single carburetter on the Phantom II. The chokes we used gave depressions of 1.2, 2.4, 3.2, 3.8 and 6.2" of mercury at 1500 R.P.M. On Rm.{William Robotham - Chief Engineer}P29 the shape of the diffuser was different to that on Rm.{William Robotham - Chief Engineer}P28, as for the smaller sizes we utilised chokes that were available for the Solex carburetter. The depression was measured at a single point in the induction pipe midway between cylinders 5 and 6. This is the usual point at which we take depressions. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||