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).
Report addressing criticisms of a car's performance, discussing design requirements, and comparing engine options.
| Identifier | ExFiles\Box 3\4\ 04-page346 | |
| Date | 22th June 1935 | |
| -2- Hs.{Lord Ernest Hives - Chair}4/MJ.22.6.35. Cont'd.{John DeLooze - Company Secretary} (7) The chassis should be designed to allow low centre of gravity with reasonable head room for a covered car. (8) The controls, steering, and brakes shall be light to operate and the braking shall be adequate for a fast car. (9) The maximum speed of the car on the road shall be 90 M.P.H. 75 M.P.H. on third speed. The chief criticisms from the reports are - (1) The car does it's job too nicely, that is, there is not enough noise and fuss. (2) Maximum speed not high enough. As regards (1) it must be remembered that we have all been trained to the idea that the best is not good enough. This not only applies to the Expl. Dept., but also Design, Manufacture, Testing and Selling. We cannot be expected to depart from our traditions easily, especially when they have proved so successful and profitable. Re. criticism No.2., of the four Bentley cars which have been made and tested No.2 the Green car which is referred to in the reports is the slowest. In a way perhaps it was a good thing it was slow. We know we cannot avoid variations in the maximum speed of complete cars, although we can guarantee the HP. on the test bed does not vary more than 5%. We have not yet completely solved why the Green car is down in performance but from the average of our other three cars we can promise 90 M.P.H. under favourable conditions on the road. We want to make it clear here, that we have not lost any performance by using the present 3 1/2 Litre Bentley engine instead of the supercharged Peregrine which was at one time proposed. We have run a Peregrine engine fitted with a supercharger and the maximum H.P. obtained is 110 under conditions which we could not use on the road without very special fuel. The H.P. of the present 3 1/2 Litre Bentley is 115. The chassis would have been the same size and would still have required the same body size and accomodation. There may have been a slight saving in weight but not very much. What we are sure of now, however, is that we should have been in for no end of trouble. The Peregrine has given us quite a bunch of difficulties as a normal engine, but if we had attempted to get 50% more power out of it these would have increased many times. | ||