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 tests with and without counterweights and a flywheel.
| Identifier | ExFiles\Box 14\2\ Scan055 | |
| Date | 1st November 1929 | |
| He/fsn5/ADS.11.29 contd. -4- (5) Test with and without counterweights repeated. with no flywheel. This time we could detect a reduction in the vibration inside the car, on fitting the balance weights with the balance weights the engine was dead smooth and rotated without a sound up to 3300 or so, but when we removed the balance weights noise came up inside the car. The test of balance weights before might have been obscured by the flywheel. Possibly removing the flywheel allowed a certain amount of vibration of the rear end of the crankshaft, and therefore at the rear feet. The noise was still by no means serious, and small in comparison with the feel of vibration on the engine. (6) Carvaler Car. We next ran this up on the drums, with connecting rods, pistons, and balance weights removed. The distortion vibration perceptible on this engine was very much worse than on S.S. Rather to our surprise it was astonishing to feel the amount of vibration in line with the centre main bearing and absolutely none about 10" on either side of this, in line with the front and rear main bearings. This was on the horizontal web along the top and bottom half joint face. There was no vibration detectable elsewhere in the engine. The top half and cylinder block are one iron casting. The effect of adding the balance weights was more marked on this car than on the S.S., they again | ||