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 results for modifications to pipes and carburettors to improve gas flow and distribution.
| Identifier | ExFiles\Box 93\2\ scan0055 | |
| Date | 6th July 1935 | |
| -6- Test No. 7. 4 Port Pipe Connected to 6 Port Head by means of special siamese connections. Fig. 12. Object. To reduce capacity and straighten out gas flows. Result. Same as test 6, except that it is noticeable that the outer cylinders are slightly starved. Fig. 12 (Round Ends. Object. To reduce starvation, by removing the resistance of right-angled bends. Result. Slight improvement, but the effect of cold pipe was too great for any reliable information to be gained from the test. Test No. 8. Twin Downdraught Carburetter (Solex) feeding separately each into 3 cylinders. (Throttles parallel to axis of main pipe). Fig. 13. Result. Slow running: required very careful adjustment to then reproduce the same results as single downdraught carb. (Test 5). Pick Up: Good. Power: See curve No. 3. Distribution: P.T. low speeds, good apart from blow-back. P.T. high speeds, good. Throttle bias:- By turning the carburetter round (at half throttle), gas could be directed into or away from the centre cylinders, causing them to be rich or starved, depending on which way the throttle opened. | ||