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 and manifold tests, noting results on slow running, fuel distribution and 'building up' issues.
| Identifier | ExFiles\Box 93\2\ scan0059 | |
| Date | 8th July 1935 | |
| -10- Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}16/KW. 8. 7. 35. (Fig. 18). This gave a very slight improvement over Fig. 17, but slow running was definitely worse. This we put down to the fact that the heavy blobs of unvaporised fuel were now being taken straight into the pipe again as a result of the increased velocity. (Fig. 19). This modification was tried, in an attempt to cut down the "swirl" effect to a minimum and thus note the effect on "building up". Result. No apparent difference from condition in Fig. 18. (Fig. 20). To get back to our original slow running it was clear that we would have to start again from Fig. 17. Working on these lines, the level of floor of the centre chamber was raised in stages, until it was level with the bore of the main pipe (Fig. 20). Result. 90% cure of "building up" trouble, and still retaining the same good qualities re slow running, distribution, pick up, power, etc. The floor, however, had been built up with lead, thus insulating to a large extent the effective heat available from the exhaust manifold (contact). The next pipe to be tested, Ea.2014 - Fig.21, has a modified exhaust manifold, which brings the contact heat up to the required floor level of the pipe. Test No.11. Single Horizontal Carburetter inclined to the main bore of pipe (SG{Arthur F. Sidgreaves - MD}9). Fig. 7. Object. To find out if there is any possibility at all in the idea of running two horizontal carburetters inclined in this manner, in the "vee" of the SpectreCodename for Phantom III engine. Result. Slow running: Very poor (no hot spot available). Heat would greatly improve this. Pick up: Poor. Distribution: P.T. low speeds - very erratic due to pulsation effect from cylinders 4, 5 & 6 working straight down the inclined nozzle against the main jet | ||