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).
Issue of popping and spitting in the exhaust of the New Phantom model, focusing on the governor control.
| Identifier | ExFiles\Box 66\2\ scan0180 | |
| Date | 1st March 1926 | |
| COPY. To BJ. CWB9/DNS.3.26. FROM CWB. NEW PHANTOMCodename for PHANTOM I. POPPING IN EXHAUST. Reference to previous correspondence on this matter and particularly to hs {Lord Ernest Hives - Chair} 2/LGG.3.26, both the alterations referred to in this latter memo: (1) new silencers (2) improved governor control, have improved matters, but popping and spitting still occur at times. The governor control is also not nearly so reliable or accurate as was that of the Silver Ghost. One cannot rely on the engine maintaining a given number of revolutions at a given setting under all conditions i.e., if the governor is quietly set with the car standing so as to maintain the engine running freely and slowly, it will often be found that after a burst at high speed followed by a traffic stop necessitating the clutch being taken out, that the engine will stop. There are about two notches difference in the governor setting for a particular number of revs. according to whether the governor is worked downwards or is worked upwards. The fact that a car will not usually pop or spit in the exhaust when the governor lever is fully closed but will do so when it is not fully closed, would appear to indicate lack of power in the centrifugal governor itself. This is confirmed by the above-noted symptom of unreliability which was more marked before the governor shafts were put on ball bearings in order to reduce friction. It would appear that further progress along the lines of obtaining more power at the butterfly throttle valve itself is desirable in order to obtain a more reliable governor and to permit the governor control being left in a position which will always ensure the engine remaining running after the clutch is taken out. Even then, there will be times when, owing to grit or dirt of slight stickiness of the butterfly throttle valve, popping will occur intermittently, which, if dirt or grit on the seating is the real cause, could only be overcome by a different form of throttle which would scrape its seating and so clean away any dirt. (Sgd.) CWB. | ||