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).
Tests concerning crankshaft and slipper drive vibration, with results from S.S. and Chrysler models.
| Identifier | ExFiles\Box 14\2\ Scan059 | |
| Date | 1st November 1929 | |
| -8- We can consider the above tests under two separate headings, crankshaft and flywheel. 1. CRANKSHAFT. Results of tests on this and slipper wheels etc. are briefly :- (1) We have shewn on the S.S. and Chrysler that the rotation of even a bare crankshaft in a crankcase can cause a large amplitude of vibration, and that the addition of counterweights effects a complete cure. (2) The above crankcase vibration can exist or be cured without the driver being much the wiser. (3) The type of slipper drive appears to affect the vibration of the engine very considerably at high speeds. (4) The new stiffer crank with large pins is no appreciable improvement, although 17% stiffer. (This is to confirmed by further tests). (5) Road tests on an S.S. showed that with counter weights fitted the car felt, if anything, worse than before. Dealing in turn with the various engine parts mentioned above : (1) Slipper Drives. Road tests shew that with the low inertia type there is much less vibration at high speeds in the neighbourhood of the top period. Early experiments on a 1-gl{G. Linnett} type of slipper drive on S-C-III car showed us the same effect. In both cases there is some reduction in | ||