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).
Test report detailing settings for a 3-B-IV Supercharged Zenith 48V1-2 Carburetter.
| Identifier | ExFiles\Box 122\1\ scan0214 | |
| Date | 5th July 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Hs{Lord Ernest Hives - Chair}/CTS.{C. Trot Salt - Carburation} 4034 Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}8/KW.5.7.35. 3-B-IV Supercharged Zenith Carburetter 48V1-2. Further tests carried out to improve carburation. The float chamber position was altered and fitted to the front. This gave a definite improvement to acceleration, especially at low speeds. The stroke of the bypass valve was increased from almost nil to .125" approx. full throttle. This enabled a smaller high speed jet to be fitted, together with an economy jet. Performance checked only on Ticknall Hill at 47 secs. c.c. The final setting is as follows :- Choke 36 m/m.{Mr Moon / Mr Moore} Main Jet 185 Comp. Jet 165 Slow Run. 85 Capacity Tube No. 1. Economy Jet 180 Ventilation 4 m/m.{Mr Moon / Mr Moore} Seating 3 m/m.{Mr Moon / Mr Moore} Pump 13 m/m.{Mr Moon / Mr Moore} Spring 600 grms. Jet 70 Leak Nil. Consumption Tests :- 14.6 m.p.g./50 m.p.h./ 71 miles. 17.3 " / 40 " / 71 " | ||