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 of the Bentley exhaust system to determine clearance between the rear axle and the tailpipe on rebound.
| Identifier | ExFiles\Box 86\3\ scan0029 | |
| Date | 25th September 1933 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} c. Ds. By.{R.W. Bailey - Chief Engineer} c. Mx.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}11/KT.25.9.33. BENTLEY - EXHAUST SYSTEM. Tail Pipe to Loc.3529 - (As 1st. fifteen cars). We have carried out tests on 2.B.IV. to determine whether it is possible for the rear axle tube to hit the exhaust tail pipe on rebound. All our experimental Bentley cars have previously been fitted with a bent tail pipe giving more clearance at this point. The tests were carried out by tying a piece of string to the frame and the axle, the length of the string being such that it became taut when the axle was within .250" of the tail pipe. The car was driven over various hump backed bridges until one was found which caused the rear wheels to leave the road. It was not possible to break the string even under this condition. The car has to be driven over such bridges at very high speeds before the axle can be made to leave the ground; one would not expect a customer to make a habit of driving in this manner. There is, therefore, no reason to believe that trouble will be experienced at this point. Although the axle will drop on to the tail pipe if the rear of the chassis is lifted, actually on the road when the rear axle leaves the ground the inertia of the axle is such that a similar rebound clearance is not produced. We understand tests carried out on some of the production Bentley cars confirm this. It has not been found possible to make the axle hit the tail pipe. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} | ||