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).
Carburetter testing to diagnose engine hesitation and weakness related to the air valve and high-speed jet.
| Identifier | ExFiles\Box 5\4\ 04-page069 | |
| Date | 27th July 1932 guessed | |
| contd:- -3- by means of a pipe. With this arrangement we proved that the movement of the valve on the instrument board was identical to the one in the carburetter so that it was possible to see at a glance at any moment the exact position of the air valve. This showed up the fact that when we have an hesitation in the carburetter which is overcome when the throttle is partially closed, the position of the valve is not effected. What we found was, that if the throttle was opened suddenly, the air valve would establish itself in a certain position, but there would be no power in the engine owing to weakness. If the throttle was gradually closed, the engine would pick up, but the closing of the throttle did not affect the position of the air valve. In order to confirm this point we carried out further tests on the test bench engine and obtained the same results. As we assumed that the weakness was due to the petrol not being supplied from the high speed jet, we tried the effect of setting a carburetter normally and testing it, and then cutting the supply off entirely from the high speed jet. We found with this it was impossible to open the throttle at all. The least opening would stop the engine entirely. We think the shortage of petrol may come from only a partial supply from the high speed jet but there certainly must be some sort of supply. Hs.{Lord Ernest Hives - Chair} | ||