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 and motoring tests to determine and reduce engine vibration by testing different crankshaft and flywheel configurations.
| Identifier | ExFiles\Box 14\2\ Scan056 | |
| Date | 11th November 1922 | |
| -5- suppressed all vibration of the crankcase. As before, however, the difference noticeable inside the car was only slight. We were motoring it in 2nd. gear and the car is becoming a bit worn and rather rough and noisy. A road test previously on this car, with and without counterweight, had shewn that a slight difference was detectable. The effect was only noticeable above 30 m.p.h. in top, and was not large; in fact the car had to be really wans to make it noticeable. We think this car is now getting so rough due to age, that the effect might be obscured, and that on a new car the improvement in high speed vibration would be more noticeable. A bad crankshaft period is now appearing for instance. (7) S.S. Motoring Test with pistons and rods to determine the importance of the flywheel booming periods previously noticed. With a plain shaft, and also with a bare crankshaft, we had obtained a marked reduction in vibration by leaving the flywheel off. We tried therefore, to see if any effect is noticeable above the additional noise with pistons and rods fitted. Unfortunately the Bump engine could not motor the car fast enough to reach the speeds at which we had noticed this effect before, due to the added friction of the pistons. (8) Road test of S.S. with half of flywheel removed. We tried a car and made a particular note of | ||