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 results for small and large induction pipes on a Bentley 6-B-IV.
| Identifier | ExFiles\Box 83\1\ scan0237 | |
| Date | 2nd October 1936 | |
| Copies to Gry.{Shadwell Grylls} FD.{Frank Dodd - Bodies} CTS.{C. Trot Salt - Carburation} Swdl.{Len H. Swindell} GR.{George Ratcliffe} To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X200a Levallois, Oct. 2nd, 1936. Bentley 6-B-IV. The comparative tests with the small and large induction pipes along with carburetters has now been completed. The results of the tests as you will see, gives no preference for either pipe, only in as much that a personal feeling of less sluggishness when accelerating from 10 MPH. with the smaller dia. pipe. Slow running and idling are good in both cases. There was nothing to choose. The idling of this engine was noticeable when we first received the car and it does not appear to have deteriorated to any extent. The following are the figures of the test :- (1) Small induction pipe and carburetters (3½ litre) Miles run 325. Average speed 46.5 MPH. Petrol used 105 litres, consumption 14 MPG. Kilometer, flying start, 25.4 secs speed 88.2 MPH. Kilometer rolling start 10 MPH. in top gear 41.4 secs. speed 54 MPH. (2) Large Induction Pipe and carburetter (4¼ litre) Miles run 324. Average speed 49.7 MPH. Petrol used 105 litres consumption 14 MPG. Kilometer flying start, 25.3 secs. speed 88.5 MPH. | ||