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).
Engine test results for downdraught carburettor performance and pipe configurations.
| Identifier | ExFiles\Box 93\2\ scan0054 | |
| Date | 8th July 1935 | |
| -5- Test No. 5 Continued. Result. (2) Downdraught Carburetter. Slow Running: Very good. Pick up: Good. Distribution: P.T. low speeds, centre cyls. weak, outer cyls. rich. P.T. high speeds, centre cyls. weak, outer cyls. O.K. Note: Varying lengths of tubular extensions were tried both between the pipe and the head, and the carb. and the pipe. These variations made no difference to the basic faults. Test No. 6. 4 Port Line mounted on 6 port line with single downdraught carburetter. Fig. 11. Object. This arrangement was used purely as an investigation into the difference between slow running on 4 port and 6 port pipes. Result. Worse than either of the pipes run separately. Reason. Due no doubt to the large area of cold pipe. Slight improvement resulted from placing blanks in the 6 port pipe to blank off the centre four cylinders, but this was still not as good as the 6 port pipe alone. | ||