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 flooding issues, jet adjustments, lever grip, and the oil level indicator.
| Identifier | WestWitteringFiles\G\August1921\ Scan36 | |
| Date | 11th August 1920 | |
| Contd. -4- HAL/LGS+S.21. ************** minute to pass the needle valve and at the same time for the carburetter not to flood. We have looked into this and suggest that it is due to the float not being submerged sufficiently when the needle valve cuts off. With the correct height of petrol at the jets, the petrol level can only be half way up the float chamber. This leaves us a very small range of movement in order to get sufficient travel on the needle for it to allow enough petrol to pass. To prove this we are making taller jets and some suitable throats so that we can raise the level in the float chamber without it flooding. The adjusting screw for the low speed jet which has to be turned with a piece of wire is awkward to operate because the heads of the countersunk screws interfere with the operation of the wire. It either means that the countersunk screws should be let in flush, which does not make a neat job, or the nut should be modified. The grip of the carburetter lever fixed to the low speed jet is not very good. There is very little spring in it owing to the fact that the two levers come away from the boss. We suggest that cheese head screws would be more suitable than the countersunk screws for gripping the levers. We suggest that the high speed throat should be made in bronze instead of aluminium. The high speed throat has the ports cut in it which operate with the air valve diaphragm. When the throat is made of aluminium it has to be very gently handled or the extension pieces are easily damaged. Oil Level Indicator. The oil level indicator is at present contd:- | ||