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).
Fitting a 20 HP car with a sub-frame to reduce body and axle noises.
| Identifier | ExFiles\Box 75\3\ scan0394 | |
| Date | 18th October 1924 | |
| B.R. 493A (20H) (D.A. 652 20-3-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}1/LG18.10.24. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} Handwritten notes: X4260 X181 X3730 X8830 XL4260 20 HP. CAR FITTED WITH SUB-FRAME. We have been carrying out experiments in order to be able to judge the relative value of the sub-frame for reducing body noises. We made suitable fittings so that we could quickly fix the body solidly to the frame and so enable us to compare it with the sub-frame fitting. Our tests shew that there is a marked improvement as regards reduction of noise inside the body when it is mounted on the sub-frame compared with when it is fixed solidly. Apart from any engine or transmission vibrations, if the car is rolling on granite sets with the engine shut off, there is a very definite improvement. Axle noises are also reduced. We therefore cannot hope, no matter how smooth we get the chassis, to get it as good when the body is fixed to the frame as it will be with the body fixed to the sub-frame. If you wish, we could bring this car to WW. and demonstrate the improvement. In the meantime we have suggested to EV.{Ivan Evernden - coachwork} that he should come to Derby as we can more conveniently make the tests here. We strongly recommend that no covered body is built for the EAC. without a sub-frame. If we start off with this arrangement, it is likely to be accepted, otherwise, if we once start making EAC.11. without a sub-frame, we shall get all kinds of protests from coachbuilders when we wish to make a change. Hs.{Lord Ernest Hives - Chair} | ||