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).
Camshaft experiments and the factors required for high power maintenance at high rotational speeds.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 167 | |
| Date | 21th January 1927 guessed | |
| Contd :- -3- was a slight improvement over standard the results were not so good as obtained with the first shaft which shewed that the longer duration exhaust was also an advantage. We have not yet completed the camshaft experiments and next we intend trying the effect of still lengthening the inlet duration by opening the inlet valve earlier. The chief factors which we have had experimental evidence to shew are the requisites for high power maintenance at high rotative speeds, are as follows :- (1) Low induction pipe depression. Appended is a curve (print No.6.) which gives the estimated power of a Phantom of compression ratio when working with a constant depression carburetter giving a manifold depression of one inch of mercury. (2) Inlet valve areas giving low gas velocity. The 20 HP. with valves ports of 1.400 dia. gives a conventional velocity of 180 ft/sec. at 3000 r.p.m. and the power peak is at 3400 r.p.m. (3) Long duration of inlet valve opening to take full advantage of the kinetic energy of the gas at high speeds. We hope to be able to prolong the power curve slightly by the use of a suitable camshaft but do not anticipate raising the peak speed to the same extent as the 20 HP. as we appear to be reaching the limit imposed by the inlet gas velocity. Hs{Lord Ernest Hives - Chair}/A.C.Lovesey. | ||