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).
Carburettor adjustments, function at low speeds, and prerequisites for tuning.
| Identifier | ExFiles\Box 178\1\ img068 | |
| Date | 26th November 1925 | |
| - 7 - EXPERIMENTAL REPORT. EXPL. No. REF. Hs{Lord Ernest Hives - Chair}/ACL/LG261125. At a speed below that at which the air valve starts to lift the carburetter is not automatic and the mixture will become rapidly weaker as the speed decreases. At such low speeds it will therefore be necessary to revert to the use of the mixture control - which is intended for use in this respect as well as a compensation for atmospheric temp. variations - in order to maintain proportionality. The air valve has been made of large dia. and light weight in order to obtain early lift and thereby get a wide range, but unless it is working freely and the diaphragm adjusted to obviate loss of movement before effectively opening the diaphragm ports, full advantage of the design is not obtained. A previous report (Hs{Lord Ernest Hives - Chair}/ACL/LG29.1 25) has been furnished dealing with the adjustment of the carburetter but the following are a few additional notes. Before any adjustment is made to the carburetter it should be ascertained that the engine is correct in other respects. The ignition should be set to operate correctly, the sparking plugs in perfect working order and the valves must seat firmly - particular notice being taken of the inlet valves - also the induction system should be free from leaks. It is absolutely useless to adjust the carburetter if any of these other factors are at fault. DISTRIBUTION AND FUELS. Uneven distribution - which could be caused by a poor (contd.) | ||