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).
Vibrations and booming noises from the exhaust, particularly when fitting 'boomy type bodies'.
| Identifier | ExFiles\Box 3\1\ 01-page118 | |
| Date | 3rd October 1924 guessed | |
| - 3 - concerned by the fixing of the torque reaction damper, as with the 40/50, but is not entirely eliminated, and is aggravated by the fixing of boomy type bodies. (b). Booming noise from the exhaust. (c). The Silencer pipe itself sets up periods of vibration. This is one of the most objectionable features, and seems to alter its characteristics when the car is in service. This is due to the expansion and contraction of the pipe, causing it to alter its period of vibration, possibly due to its "nodal" point being affected. As illustrated to you recently, this was very bad on a car at engine speeds equivalent to 20 m.p.h. on top gear. Apart from this there is also the exhaust pipe vibration which takes place under periods of running of dead slow engine speeds, and which are very objectionable at light load slow speed conditions when fitted with a boomy type body. The above are a few of our experiences. Apart from the above, however, we still feel that the attention of our body experts in London should be to avoid the use of these "boomy bodies" or at least to tackle the job with the idea of fitting bodies which are constructed to be free from these troubles. We find, for instance, that the following are features of bodies which are very sensitive, and when being struck set up booming:- Cross bars in the roof. Large windows. Floor Boards Front wind screens. Luggage carriers, front wings etc. Some of these features were illustrated to H.{Arthur M. Hanbury - Head Complaints} today when at the Works, and cause it to be almost difficult for us to produce chassis which are entirely free from movement or vibration of some sort or other. According to reports it appears to be of vital importance that the side frame structure for body support should be tested out and standardised. EQ EP.{G. Eric Platford - Chief Quality Engineer} | ||