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 the S.U. Carburetter Co. Ltd. regarding carburetter needle seatings and flooding issues.
| Identifier | ExFiles\Box 121\3\ scan0057 | |
| Date | 21th July 1939 | |
| 1031 Experimental Dept. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}9/MH.{M. Huckerby} 21st. July, 1939. The S.U. Carburetter Co. Ltd., Adderley Park, BIRMINGHAM, 8. For the attention of Mr. Cooper. Dear Sirs, Further to our telephone conversation yesterday re needle seatings in our carburetters. Assuming that the float chambers and mechanism are identical for both H.4 and H.6 carburetters, the following figures can be taken for both. We have carried out a simple check as follows:- With the float chambers disconnected from the carb. bodies there is a free flow of 65 pints per hour from each carb. making a total of 130 pints per hour for the engine. Maximum engine requirement is 80 pints per hour. It is interesting to note that the same flow is given with either the .100 seating or the .125, so that there is every reason to go for the smaller seating as an extra safeguard against flooding with rubber engine mountings etc. There is a point which we have mentioned several times regarding flooding, and which is till giving us a certain amount of trouble. That is switching on (electric pumps) with empty floatchambers. The geometry of the fork controlling the needle movement is still such as to cause occasional jamming, and subsequent full bore flooding. | ||