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).
Visit to the S.U. Company to discuss fitting carburettors to a Merlin engine.
| Identifier | ExFiles\Box 121\3\ scan0089 | |
| Date | 14th November 1940 | |
| 1031 To Jnr.{Charles L. Jenner} from Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} C. to Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} VISIT TO S.U. COMPANY BIRMINGHAM. PURPOSE. 1. To discuss the practical means of fitting horizontal S.U. (chassis type) carburettors to a Merlin engine, to operate under naturally aspirated conditions. 2. Arrangement of suitable electrical petrol pumps for use with 1. 3. To determine the state of development to date, of their new down-draught expanding choke carburettor (chassis). 4. To impress upon them the serious problem of sticking pistons (air valves) on the model H.4. horizontal chassis carburettors. RESULT. 1. The largest horizontal carburetter available has a 2.300" throttle bore. This is shown on their drawing 1S640 Body (detail drawing), and two drawings without numbers, one showing the interchangeable variable jet assembly, and the other in outline drawing of the carburetter. These prints are attached to Jnr.{Charles L. Jenner}'s copy of this memo. The various means of locating these carburettors with suitable piping were discussed, but not beyond the anticipation of troubles to be encountered by right angle bends, etc.. Regarding the disposition of the carburettors, the limitations appear to be as follows:- a.{Mr Adams} Rm.{William Robotham - Chief Engineer} has stated that a desirable feature is that the height of the rocker cover should fix the maximum height of the engine. From this would follow: b. That the carburettors will not fit into the vee, complete with the air intake connections. If this means that the carburettors will feed from front and rear of the engine, the induction pipe is going to be a critical problem, and the fact that oil bath air cleaners are required will mean either two of these or a long interconnecting air intake pipe. Leslie Kent (S.U.) gave us the benefit of their experience on such an intake, which is that it seriously upsets the normal functioning of the carburetter if a length of intake exceeding 3.00" is used. Up to the outbreak of war, they were concentrating a large effort towards developing a satisfactory intake for the smaller Morris cars. They did not succeed in getting anywhere beyond learning that | ||