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).
Comparative test report on four different induction systems for the Bentley III and Bentley 30 models.
| Identifier | ExFiles\Box 99\1\ scan0013 | |
| Date | 10th May 1938 | |
| 808 also 408 To By.{R.W. Bailey - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} c. to Da.{Bernard Day - Chassis Design} c. to Da{Bernard Day - Chassis Design}/JH. c. to Sm/CH. Rm{William Robotham - Chief Engineer}/CT.S/JH.10.5.38. INDUCTION SYSTEM. BENTLEY III AND BENTLEY 30. We have carried out a series of comparative tests to determine the relative merits of four types of induction systems regarding fuel economy and general efficiency. (1) Single downdraught Stromberg type EC.42. (2) Twin choke downdraught Stromberg type AA.{D. Abbot-Anderson}25. (3) Single horizontal S.U. (4) Two horizontal S.U.'s. Of the four systems mentioned above (1) and (4) are more fully developed than (2) and (3) by virtue of the fact that they have been developed for our present production engines. The twin choke Stromberg for instance could be made to show more useful gain over the single Stromberg, if a little more development work were carried out on the mock-up experimental induction pipe to which the twin choke Stromberg is fitted. The same applies to the single horizontal S.U. and this must be borne in mind when reviewing the power figures coupled with this report. We are more interested however in the part throttle characteristics of the different carburettors, as it is ability to give complete correction for part throttle mixture, which is the main controlling factor when considering their use on our engines. From the graphs attached, it is seen that no particular arrangement shows any startling power gain over the next. | ||