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).
Car body 'booming' and vibrations from the engine and road.
| Identifier | ExFiles\Box 137\4\ scan0125 | |
| Date | 26th November 1930 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} X634 R4/M26.11.30. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} C. to DA.{Bernard Day - Chassis Design} BOOMING. If there is anything on a car which has a natural period of vibration at all suiting any vibrations derived from the engine and gearbox, or even from the road - such as wooden setts - these parts will, in spite of all our efforts, synchronise and be put in motion with very slight exciting forces. We all realise this by the fact that new bodies compare badly with the old ones, and metal and wooden structures compare very badly with fabric. Some of the metal bodies are made by the engineers with such care as to have very little of their panel or roof surface that can vibrate. They are generally constructed with spherical surfaces which are very stiff. We cannot hope to make a motor chassis entirely free from exciting forces from some parts, such as the intake, exhaust, and revolving and reciprocating mechanisms. These get more difficult as the speeds get higher, and as you are well aware much of the present increased performance has been obtained by increased number of revs, and reciprocations of the moving parts, that is to say, the increased HP. is not so much an increase in the gas pressure as we succeeded in getting gas to fill up the cylinders when the engine is running at faster speeds, and we so obtain something like 50% more power than we did a few years back. High frequency vibrations seem to synchronise more readily. R.{Sir Henry Royce} | ||