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).
Road tests to investigate and resolve scuttle shake issues.
| Identifier | ExFiles\Box 117\3\ scan0025 | |
| Date | 6th May 1940 | |
| COPY. -2- Rm{William Robotham - Chief Engineer}/FD.{Frank Dodd - Bodies}1/SW.6.5.40. Attached is a report of the progress, and to avoid con- fusion, we have only included results showing progress in the right direction. First of all, a complete set of readings were taken from 30 m.p.h. to 80 m.p.h. at constant speed, with the car in standard condition. These road tests were all run over the same section, and as a white line was running down the centre of the road, this acted as a guide for our off-side wheels, making comparison as near as possible for every change in construction. In the attached sheet No.1, we show a reproduction of the strip record for the standard conditions from 30 m.p.h. to 80 m.p.h. From these tests we found that the scuttle shake had a peak period at 60 m.p.h., therefore to avoid wasteful use of time and petrol, all our further tests were carried out at a constant speed of 60 m.p.h. The next test was carried out with the scuttle fixing to the frame made solid, the silent block rubbers having been removed and replaced by steel, at the same time triangular stays were bolted to the top of the dashboard, the latter having been strengthened on the engine side with angle iron for stiffening purposes. The triangular stays were taken from the top corners of the dashboard to the top corners of the scuttle, a sketh of the arrangement is attached. The effect of these are shown on Strip No.7, it will be seen that the amplitude is slightly less, and that the fre- quency is higher. Thinking that the dashboard might be moving in a fore and aft direction at the shoulders, diagonal stays were next tried from the dash forward to the side of the frame (see photograph) but as the results show in strip No.8 no improve- ment was effected. At this stage in the road tests it was decided to run the front on the bumper rig to enable us to get round the car, and observe where the shake was actually taking place. -cont'd- | ||