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).
The diagnosis and repair of an exhaust system issue causing vibration and drumming on Mrs. Corrigan's car.
| Identifier | ExFiles\Box 47\3\ Scan392 | |
| Date | 1st March 1932 | |
| Sg. {Arthur F. Sidgreaves - MD} ..from PN. {Mr Northey} Copy to Hs. {Lord Ernest Hives - Chair} Sg. {Arthur F. Sidgreaves - MD} . Jus Br.. X4117 PN. {Mr Northey} 1/HTS.3.32. 40-JS. {Mr Johnson's Secretary} Mrs. Corrigan. This car went to N., and on examination the exhaust system was found to have been distorted whereby the sliding sleeve in front of the rear silencer had failed to function, the front silencer was jammed against the rear sprin shackle, and the consequent strain set up undoubtedly would have an extremely undesirable effect on the general vibration and tendency to drum. The necessary repairs were effected to these parts and the provision of an additional stay made to the cross-member midships. this stay-bracket being standard in cases of trouble, and I believe fitted nowadays in production in all cases. The car was tested by Messervy and the general drumming tendency found to be considerably improved, especially at the 18/29 m.p.h. period, but no improvement was found in connection with the 55/60 m.p.h. period. The rear engine feet were then disconnected in order to find out whether by this description of engine isolation a marked improvement might be found such as is established with diamond engine mounting. Subsequent tests however showed that the improvement from this cause was so small as not to justify the expense of being permanently carried into effect. It would appear that this last remark would equally apply to any proposition to fit diamond engine mounting. I accompanied Messervy this morning on a final test of this car with the new exhaust repairs finished, and there undoubtedly was a general improvement in respect of drumming although this does not apply to the 55/60 m.p.h. speed. I consider the car quite a good example of our production, but in view of the very difficult description of the owner we have to deal with in this case, one could not be certain that she will be satisfied. Much we felt depended upon the impression which her driver Marini obtained after taking the car for a test this afternoon. This was done, and I am glad to say that not only did he appreciate the careful and intense | ||