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).
Letter to Zenith Carburetter Co. Ltd. regarding road test results for the Type 48V1-2 carburetter.
| Identifier | ExFiles\Box 122\1\ scan0194 | |
| Date | 7th June 1935 | |
| X1034 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}14/KW. 7th June, 1935. The Zenith Carburetter Co.Ltd., 40-44, Newman Street, London, W.1. For the attention of Messrs. Palmer & Howell. Dear Sirs, Re Carburetter Type 48V1-2. With reference to our conversation on the 5th inst., we have now tested this carburetter with the float chamber fitted at the front. This gives a definite improvement on the low speed faults previously experienced. Acceleration up to 25 m.p.h. considerably improved, and the flat spots at 28/33/35 m.p.h. cured. The chief faults at the moment are (1) changeover from idle to main or progressive feeds; (2) consumption heavy at high average speeds. Further to our conversation of (1), the pressure of feed is 1.5 lbs/sq.in. to a possible maximum of 2 lbs/sq.in. A max. flow of 60 pts/hr. is required so that the present seating unit of 4 mm. may be reduced to advantage. On road test further trials showed the following :- Slow progressive acceleration, carburation good. Part throttle (approx. 1/3) acceleration along level road, shows lag 4 to 8 m.p.h. Immediately this period is overcome, the metering during further acceleration is very bad, the mixture being strong up to 20 m.p.h. This may be a clue to the fault of lag at low speed; i.e., heavy charges of fuel from carb. being chief offence. | ||