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).
Weight distribution and diagnosing engine knocks in Phantom III cars.
| Identifier | ExFiles\Box 131\3\ scan0100 | |
| Date | 22th June 1939 | |
| - 5 - variation in weight distribution as between individual cars to be able to predict exactly what springs or damping will be required to suit a certain body specification. Mainly, however, it is a question of damping which can easily be applied, and we have provided Depots with full information to enable them to deal with complaints from customers, or from JLE{J. Lee Evans - Chassis Test Manager} if he considers the ride of any new car is not up to the standard expected. Experimental Dept. are trying the effect of adding weight to certain of their cars in order to simulate weight distribution comparable with some of these big limousines so that ride characteristics can be reproduced. 6. Engine Knocks on Phantom III. We have recently collaborated with the Repair Dept. in dealing with mysterious knocks on two Phantom III cars - Dr. Roland Perkins, 3.AX-143 and Denis Becker, 3.BT{Capt. J. S. Burt - Engineer}-65. There was a similarity in the knocks which suggested the same cause, but this is not at all certain. In the case of Perkins, the knock could be cut out by shorting No.4.B cylinder, thus suggesting a piston knock. This piston and sleeve was changed in January for the same reason, but the knock persisted, and the piston and sleeve have been changed again without improvement. As it was found that variations in the tappet adjustment would vary the intensity of the knock, the camshaft and tappets were changed, again without result. As Dr. Perkins was getting impatient, it was decided to change the engine for the one in the Trials car we have been using in connection with tappet wear investigation, and to solve the engine knock in this car afterwards. This is now being proceeded with, and it may have useful results as there is a feeling that a similar knock can be produced on other Ph.III cars if one is sufficiently critical. In the case of Becker, the symptoms were similar, in that the knock could be cut out on No.4.B cylinder, but, in this case, there was direct evidence when the engine was stripped down that the oil supply to No.4.B gudgeon pin had been cut off due to the big end bearing shell having been fitted the wrong way round, thus obscuring the oil hole. (continued) | ||