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).
Experiments to reduce gas flow restriction in a hot-spot by introducing a vane and modifying the carburettor.
| Identifier | ExFiles\Box 93\4\ scan0108 | |
| Date | 24th February 1937 | |
| -2- From these results it will be seen that there is an appreciable restriction to the gas flow through the hot-spot in standard form (1) amounting to 1.8" Hg. which represents approximately 18.B.H.P. The introduction of a horizontal vane in the box (2) to stop swirling is a definite improvement in reducing this restriction to 1.2 Ins.Hg. We should like you to endeavour to re-design the hot-box with a view to reducing this restriction for trial experimentally. It will be remembered that the existing hot spot is a definite improvement over the originally designed hot spot. Freeing off the carburetter by means of fitting 1 5/8 chokes against std. 1 5/16. or 50% increase in area makes only a small difference in the resultant depression as taken in the manifold, from 3.5 Ins.Hg. to 3.0 Ins.Hg. compared with the restriction in the 'hot spot'. Other experiments have been tried including opening up the branch pipes from 1 1/2 to 1 5/8 dia., removal of the protruding parts in the hot spot with little or no improvement. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||