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).
Performance differences between Bentley and Wraith induction systems.
| Identifier | ExFiles\Box 122\4\ scan0201 | |
| Date | 28th October 1938 | |
| Ry. from Rm.{William Robotham - Chief Engineer} c. HS.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. Mx.{John H Maddocks - Chief Proving Officer} c. Rm{William Robotham - Chief Engineer}/OTS. INDUCTION SYSTEMS & PERFORMANCE. The attached report indicates that there is a definite improvement to be gained by using the Bentley system with two carburetters, as compared with the Wraith and one carburetter. The performance is greater than one would expect from the power curves, which are also attached. However, the power curves show that the advantage lies with the two carburetters. There is no doubt that if there were serious complaints of the Wraith performance we could improve it to a noticeable extent by raising the compression ratio to 6 1/2 : 1, and also by using two S.U. carburetters. There is no doubt, however, that after doing this the car would be less pleasant to drive from the point of view of the man who is not interested in the performance. We have, therefore, not proceeded along these lines. The question of policy arises, as now the only difference between Wraith and Bentley lies in the induction system. With a view to retaining the difference between these two engines we are trying to get an induction system to work with a Duplex Stromberg carburetter, which being a double throat instrument might be expected to give us similar characteristics to two S.U's. Rm.{William Robotham - Chief Engineer} | ||