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).
Engine vibration, knocking, and potential damper solutions for 6-cylinder engines.
| Identifier | ExFiles\Box 65a\3\ scan0284 | |
| Date | 8th May 1931 guessed | |
| (3) The trouble with bonnets wearing their strips and knocking cannot now be considered passable because we know the reason, and they are curable. 18-EX. is better than any previous type. The damper I suggest for present 6 cyl. engines is similar to an ordinary brake drum internal type, probably aluminium steel lined, and the brake is a split ring covered on the outside with fibre or other no-seizing material sprung outwards by its own elasticity and arranged with extra weights to increase by centrifugal loading as found good by experiment. But even with best dry surface and friction increasing with speed the crankshaft must vibrate or the damper does not act. Is this not so? (Mr. Ricardo thought our trouble was the whirling flywheel, and remarked that by far the smoothest 6 cyl. engine he had had experience of was that with the flywheel in the centre, which I have since thought is what we ought to use if we go on with 6 cyls.) The actual trouble from want of perfect balance or variation in kinetic energy in the pistons is extremely small and would move the engine only a microscopic amount. I had made up my mind to ask Mr. Tresilian or Mr. Grylls to find this quantity but have since decided that it is proved by the smoothness at 45 MPH. (1700 RPM.) so that the swing at the worst harmonic must increase this 100 times. R.{Sir Henry Royce} | ||