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).
Technical note on adjustments and tests for variable valves and diffusers.
| Identifier | Morton\M19\ img231 | |
| Date | 17th September 1931 | |
| Hs{Lord Ernest Hives - Chair}/Swn.1/AD17.9.31 contd. -3- Variable valves and diffusers. By making the feed holes in the variable valve sleeves (.066 dia. and three in number) we can with the existing variable valves obtain a good mixture range, giving ample adjustment for richer or weaker settings. With regard to the diffusers the full throttle metering is good, though it was found that appreciable loading up at low speeds full throttle occurred when on road test and that by raising the lower row of holes in the diffuser this was cured. The throttled metering is by no means correct and as yet we have still work to be carried out before definitely deciding upon diffuser details. We are using 1.300 dia. chokes, these maintaining good acceleration, with an increased power at high speeds over the 1.25 dia. chokes. Power curves in comparison with standard carburettor have been previously sent to V.1023. We shall endeavour to get the carburetters to function satisfactorily with 1.4" dia. chokes as these are a considerable advantage with the long duration camshafts. Hs{Lord Ernest Hives - Chair}/L.H.Swindell. | ||