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 throttle issues, slow running, and causes of firing in the silencer related to throttle wear and carbon deposits.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan033 | |
| Date | 7th October 1926 guessed | |
| -4- Contd. the extra petrol could be used without upsetting the normal slow running of the engine; it was found that the smallest throttle opening necessary to run the engine is 1 1/2°, this gives a road speed on top gear of approx. 3 m.p.h. Before this point is reached the extra petrol feed must be cut off, otherwise the slow running of the engine will be interfered with, the range is almost too small to be a working proposition. If, however, it could be arranged to work within these limits it would be a decided advantage. Explosions would be eliminated under closed throttle conditions and also those due to a poor fitting or non-closing throttle would be done away with. Conditions causing leaking and non-closing throttles. ------------------------------------------------------ There is no difficulty experienced with new production chassis with regard to firing in the silencer. This immunity from trouble can be traced to good fitting throttles; with a good throttle and sound induction system together with correctly set controls no real trouble is experienced. These cars, good in this respect when new, return to the Repair Dept., after considerable use, the owners complaining of firing in the silencer. In each case the trouble is overcome to a satisfactory degree by ensuring that the throttle closes correctly and is a good fit. The alteration to the condition of the throttle after considerable running is due to :- (a) Carbon deposit on the valve and throttle body. (b) Wear on the throttle spindle bearings. Contd. | ||