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).
Investigation into whether the chassis or the body is the cause of 'booming' and vibration issues in P.2. & 25HP cars.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan044 | |
| Date | 13th March 1931 | |
| HS.{Lord Ernest Hives - Chair} SG.{Arthur F. Sidgreaves - MD} ) FROM R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer} DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} ) (At Le CanadelHenry Royce's French residence.) C. to WOR.{Arthur Wormald - General Works Manager} PN.{Mr Northey} C. EP.{G. Eric Platford - Chief Quality Engineer} BOOMING CARS - P. 2. & 25HP. ORIGINAL RECEIVED R2/M13.3.31. x634. filed. Your memo. of 6.3.31. to hand. Everyone agrees, and I believe, we are all trying hard to make the best of our present production. Mr. Elliott representing the design, Mr. Hives the Expl. Dept., and Mr. Evernden the bodywork, should between them come to some very definite conclusions about the following points on which there is still much difference of opinion. (1) Your memo. mentioned above says that in the case of Mr. Davies changing the chassis made a bad car into a good one, which if true means that the chassis are not all alike. This is of enormous importance but I cannot believe that it is true. It is the first time I remember hearing that the bad car follows the chassis and not the body. To save time let us assume that it is true, then the bad chassis, after proving that it is bad by repeating the experiment should be examined by RHC.{R. H. Coverley - Production Engineer} to find if any parts are out of balance or out of truth. Naturally I should be delighted if this tale is true because if we can make one good chassis we can make them all good without much expense. (2) Again to save time let us assume that HS{Lord Ernest Hives - Chair}' opinion as I understand it is true, viz: that the bad car follows the body, then we must conclude that all the chassis generate vibrations and that some bodies amplify them more than others, and I fear this is the true tale and we come back to our efforts to make the best of our chassis, and also to condemn and refuse all bodies which are persistent boomers. I am hoping that some of the suggestions may have done some good but the reports have been very inconsistent except as I understand nothing we know can make a bad boomer into a good car. For the reason of bad steering and jellying we cannot insulate the engine from the car in the way which is reported good for torsional vibrations - i.e. very soft rubber feet. If we find that the diamond mounting with very soft rubber feet is definitely beneficial then it suggests that the cause of our dissatisfaction is variation of torsional reaction, and not whirling flywheels, bending crankchambers, or any - out of balance. Here again I am afraid that the tale is not true - i.e. that "The diamond mounting with soft rubber feet would cure all our "imperfections if we could use it." One knows for certain that it would improve very definitely the vibrations arising from the variation in torsional reactions, but does it make the chassis completely satisfactory compared with the best known of the 6 cyl. big engine type? Naturally we must not expect even this mounting to be entirely perfect for the duty it is intended, but it might prevent much of the energy of these torsional impulses from reaching the frame and the body. It should be realised that the sources of torsional vibrations cannot be reduced by (1) | ||