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).
Carburettor jet settings and their effect on fuel consumption.
| Identifier | ExFiles\Box 147\5\ scan0152 | |
| Date | 31th May 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}8/JH.31.5.38. With the stronger 30 H.P. setting of .063 main jet the vacuum control advance shewed an increase in consumption of .4 M.P.G. average. With the weaker setting of .056 main and .038 byepass jets the vacuum control advance shewed an improvement of .6 m.p.g. up to 50 m.p.h. This weak setting is not applicable to production being too weak just before the byepass or economiser jet comes into action. All tests were carried out with the same carburettor but a second one was checked at 45 m.p.h. average part throttle giving 18 m.p.g. as compared with 17.1 m.p.g. on the former. Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe} | ||