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).
Crankcase and crankshaft vibration and distortion during testing, with a comparison to a Chrysler engine.
| Identifier | ExFiles\Box 14\2\ Scan063 | |
| Date | 8th November 1929 | |
| -12- the complete crankshaft, great lateral stiffness of the shaft, and in addition possibly some degree of support from the crankcase. We have striking evidence now from the front, middle, and rear of the crankshaft, all of which indicates the state of vibration at high R.P.M. (S) CRANKCASE. During our tests recently, we have observed that crankcase vibration and distortion is usually local, i.e. in the webs. When we ran the S.S. under rather artificial conditions with no cylinder head (bare crankshaft in the crankcase with cyl. blocks but no head), we observed the whole crankcase hogging and sagging. When we fitted the cyl. head the cyl. blocks and top half of the crankcase were much steadier and felt almost dead smooth, yet the horizontal web along the joint flange still vibrated as much as before, indicating the state of affairs inside the crankcase. On the Chrysler the localness of the vibration was still more marked. On this car, with a fairly stiff cast iron engine, a feeling similar to an electric shock could be got from the horizontal lateral web at the top and bottom half joint face, in line with the centre main bearing (plain crankshaft less balance weights rotating inside). Yet a few inches away the metal all round was quite smooth. There is no doubt that this distortion | ||