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).
Tests conducted on six-cylinder pipes and carburetter configurations.
| Identifier | ExFiles\Box 37\4\ scan 053 | |
| Date | 23th March 1918 | |
| Contd. -2- EH1/LG23.3.18. it would be a pity to tie it up so that a larger pipe could be used. The tests with the six cylinder pipes are very encouraging but as one anticipates the distribution is not as good as with the 4 carburetters. We also found with the arrangement of pipes we tested, that the distribution was very sensitive to the direction of the air inlet for instance, we could make either set of three cylinders strong by turning the carburetter 180°. We could also affect the distribution if, when the engine was running full throttle we deflected a current of air into the air inlet. If we used a six cylinder pipe x.3285 so that there would be no blow back, we could then use a straight through carburetter with a concentric ring float similar to the H.C.8 this would avoid bias being caused on the mixture. We are now preparing a set of pipes made to LeC.911 with a greater ramming length in the three cylinder branches and shorter pipe in the carburetter. The only point where we stand to lose on the one carburetter for six cylinders is on consumption, but we believe that there is a possibility of getting this down to .5 lbs per HP hour. We are trying the effect of a smaller carburetter on six cylinders as by the curve it looks as though we can use one We ought to be able to give full particulars of the possibilities of the 6 cylinder pipe in a few days. EH. | ||