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).
Letter discussing petrol supply issues at high altitude and a proposed 'bye-pass' system solution.
| Identifier | ExFiles\Box 149\1\ scan0168 | |
| Date | 19th July 1935 | |
| To Hs.{Lord Ernest Hives - Chair} from Sg.{Arthur F. Sidgreaves - MD} Copy to E.{Mr Elliott - Chief Engineer} H.{Arthur M. Hanbury - Head Complaints} re H.C.Martineau. B160-DG. Sg{Arthur F. Sidgreaves - MD}9/E19.7.35 I received a letter from him which contains a rather extraordinary point. The following is the extract in question: 'There is another very important mechanical point that I should be very glad if you would take up with your designers so that you can fit it on my return. I have been forced to return on two passes, the Galibier and the Stelvio, owing to the fact that in both cases, at somewhere above 8000-9000 ft., the pump cannot supply the carburation with petrol. I am convinced this is due to the difference in atmosphere at that altitude, as in neither case was the temperature of the engine hardly over 85°, while revs were kept below 1500 on gears. Both times, up to that height, no trouble was experienced, and I could keep my hand on the pump and petrol pipes, showing that overheating was not the cause. 'At more normal levels on the Autostrada and the long straight roads in France, I can 'keep my foot down' indefinitely and not produce the slightest sign of 'drying-up', so I am convinced that the difference of the air at that altitude is the reason. 'I would suggest that the simplest method is to put a 'bye-pass' on the petrol system which would enable one to switch over to the old fashioned hand pump pressure system. I should'nt imagine this would be very difficult. (Needless to say, little Ballila Fiats, small Opels & Citroens, & large charabancs seem to find no difficulty at all!! But the American Hudson, Packard and Studebaker etc. do...)' I am at a loss to understand this because Mr. Bentley went all over the Alpine Passes last summer, as you know, and specifically mentioned in his report that he experienced no trouble with petrol supply on mountain passes up to 9,000 feet and with a shade temperature of 95°. Can you please throw any light on the subject? Sg.{Arthur F. Sidgreaves - MD} | ||