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).
Resolving noise from a front shock damper filter and addressing engine mounting imbalance.
| Identifier | ExFiles\Box 5a\3\ 03-page094 | |
| Date | 13th November 1931 | |
| Hotel de France, Chateauroux, FRANCE. 75840 To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From G.W.H. 13/11/31. 18.G.IV. During our run over here we had considerable bumping on the front. The noise was too much of a metallic sound for it to be the rubber buffers. Upon our arrival here we found that the noise is caused by the side steering tube hitting the filter of the front shock damper. The position of the filter on these front dampers must be of a new design as we have not previously had this trouble, and I have not noticed the filter on the side of the damper previously. We enclose a rough sketch showing the approximate position. Our buffer clearance was 2" whilst the clearance between the side steering tube and the bottom filter was 1.875". We have packed the rubber buffer down 1/4" making the buffer clearance 1.75" to get over the trouble temporarily, but it is definite that this arrangement is not satisfactory and the filter of the damper will have to be altered. Re. Diamond Mounting of the Engine. We have gone over the diamond mounting of the rear engine paying special attention to the rubber blocks of the rear engine feet. We would like to draw attention to the fact that when the rubber blocks are taken out, the engine will not balance itself centrally, that is, the clearance between the engine feet and the frame on the bracket is 1/8" less clearance on the N.S. than that on the O.S. We disconnected the silencer pipe, water tubes to the radiator, and dismantled the clutch pedal shaft, and found that the cause is due to the extra weight of the engine on the N.S. This of course, you will understand, places a greater compression on the N.S. of the engine than on the O.S. To overcome this we have taken a packing piece from underneath the cup of the rubber block at the N.S. and introduced it underneath the cup at the O.S. This balances the engine up in a stationary position with no load on the rubber blocks. We are hoping with this setting to obtain less tendency of body booms. The full results we will give you in due course. We are interested to know whether you find the above results are consistent with other engines. G.W.H. G.W.Hancock | ||