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 comparing the performance of a 4-port pipe against a 6-port pipe, focusing on slow running and petrol distribution.
| Identifier | ExFiles\Box 93\2\ scan0058 | |
| Date | 8th July 1935 | |
| -9- Ha/CTS.{C. Trot Salt - Carburation}16/KW. 8.7.35. This fault on the pipe in question was not taken seriously, because we were concentrating on how slow running could be obtained. If we could get slow running on a 6-port pipe of this description, and understand how we had obtained it, the "building up" feature could be tackled as a separate job. Having failed therefore for the moment to produce the desired slow running on a "six port" pipe, we made direct comparisons on a new 4 port pipe. Test No.10. Ex.18316/7. Figs. 17, 18, 19 & 20. Object. In producing this pipe, the following points have been borne in mind. (1) To produce a four port pipe, with approx. the same resistance at each bend. (2) To cause the gas to follow the nearest one could possibly get to a straight path, from the carburetter to the ports. (3) To produce a centre chamber which would deal effectively with the unvaporised petrol, without suffering from the faults already encountered on the 6 port pipe. Result. Fig. 17. Slow Running: Very good. Pick up: Good. Distribution: P.T. low speeds - Very good, but suffering from the same "building up" fault as the six port pipe. We find therefore in this pipe, that everything else being present, we can now tackle the "building up" as a separate problem. Our first idea of a possible cure was to increase velocity by reducing the capacity of the centre chamber. This was carried out in stages.(Fig.17). This gave a 50% improvement to the building up trouble. | ||