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).
Discussion following tests on a Claudel Hobson carburetter, considering compression changes and potential horsepower gains.
| Identifier | ExFiles\Box 121\3\ scan0020 | |
| Date | 26th February 1915 | |
| C O P Y. 23/5 To Wor.{Arthur Wormald - General Works Manager} for EH from R.{Sir Henry Royce} Copy to J.{Mr Johnson W.M.} " " E.{Mr Elliott - Chief Engineer} " " Na.{Mr Nadin} COPY R1/IB26215. February 26th. 1915. Re Claudel Hobson Carburetters. X 14 R Thank you for your report on the two tests of the Claudel Hobson carburetter and the change of compression. I think it is quite worth while putting the 32 m/m Claudel Hobson carburetter on a car and seeing how it behaves, as the gain in horse power seems to be quite high, in fact, one would expect that if you combined the Zephyr Piston, the Claudel Hobson carburetter, the high compression of, say 80 lbs., and the more rapid opening of the valves, one might get a horse power of about 90 with the cut-out open. I shall also be pleased if you will find out whether the cut-out open is as effective as a long straight exhaust, such as was fitted to Mr Radley's car and the old T.T. cars. Referring to the compression, I assume that you have taken this with a gauge, with one of the cylinders not firing, but you do not say at what speed this compression was taken. It is interesting to note that the improvement in consumption is greater than the improvement in power. This would appear to suggest that the combustion of a weak mixture is more complete or rapid with the higher compression, and it also shows that a weaker mixture gives the maximum | ||