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).
Eliminating engine explosions by adjusting the fuel mixture in the induction system.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan032 | |
| Date | 7th October 1926 guessed | |
| -3- Contd. carburation is at full weak than when full strong. As in (a) and (b) a leak in the induction system greatly intensifies explosions, they are decidedly more noticeable under all carburetter settings. It is possible to eliminate these explosions by introducing a large air leak or by injecting petrol into the induction system. The air leak necessary to do this is very large and impracticable; the amount of petrol required to richen up the mixture sufficiently to eliminate explosions under any conditions was measured by means of an adjustable jet. The setting of the jet to cure explosions was noted and the equivalent petrol flow through the jet afterwards measured under a pressure equivalent to the maximum depression recorded in the induction pipe at closed throttle. The induction pipe depression at closed throttle is at its maximum at 22" mercury. The petrol flow through the jet under this pressure was measured and found to be 1.745 pts/hr. This is sufficient to eliminate explosions under any conditions. During the above test the jet was not connected in any way to the throttle mechanism,(i.e. it was not shut off as the throttle was opened); it was found that this extra petrol was sufficient to seriously upset the slow running of the engine. In view of the possibility of utilising a scheme such as the above, in which extra petrol is fed into the induction pipe at closed and nearly closed throttle positions, tests were carried out to determine over what range of throttle opening Contd. | ||