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 noises and general running behaviour.
Identifier | ExFiles\Box 23\5\ Scan052 | |
Date | 18th January 1928 guessed | |
contd :- -3- is not released immediately the engine commences to run under its own power; the pinion is not released from the flywheel gear until the operating pedal is released. Engine noises. The valve gear is quiet if the valve clearances are correct. The tappets need constant attention to ensure that the clearances are correct; they invariably require re-adjustment after running the car in 2nd. gear about 40 m.p.h. The timing chains howl at anything but the lowest speeds i.e. about 20 mph. Carburetter suction noises are bad, especially at the low speeds the majority of noise emanating from the idling jet air intake holes; at higher speeds this noise is not excessive. Apart from these noises, none of which are really objectionable, the engine is quiet. The exhaust system is very quiet, no exhaust noises can be heard from the drivers seat. There is rather an objectionable boom between 25 and 35 m.p.h. which appears to be an exhaust boom; it is worse on pulling than on the overrun. Apart from this there are no exhaust booms at all either when driving or on the overrun, the overrun is particularly good in this respect. GENERAL IMPRESSION OF ENGINE BEHAVIOUR. The engine is very smooth with the exception of two marked periods. The slow running is good and exceptionally vibrationless. If the engine is 'revved' up light, the smoothness on both forward and overrun is immediately very apparent, no retard periods or roughness of any sort can be felt. Torque reaction vibrations are so slight as to be negligible. There are two engine vibrations which spoil the otherwise very smooth contd:- | ||