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 roughness tests, focusing on flywheel bearing support and crankcase deflection.
| Identifier | ExFiles\Box 11\3\ 03-page289 | |
| Date | 14th November 1930 guessed | |
| -3- ENGINE ROUGHNESS. We are getting most consistent results on these tests especially with regard to the flywheel rear bearing support. We are rather disappointed with 18-G4 now we have run it a bit further, the so called flywheel period has become very marked indeed. We rather suspect that this is due to the increased clearance which we have had to give to the Hall's bearing metal. Since we do not wish to compromise R's new flywheel by this bearing metal we shall fit standard bearings for the 10,000 miles test, which should start on November the 27th. One thing that gives us a definite result every time is reducing the rigidity of the crankcase by taking off the cylinder block. When we were doing the bending test with the 20 HP. flywheel we took the bottom half off and examined the behaviour of the flywheel bearing. The deflection which takes place on this bearing astonished us and we rather think that it is the rear section of the crankcase which is going rather than the bearing cap. It is very difficult to measure this but we are trying to sort out the deflection. The points upon which any information you can give us as to American practice would be invaluable, are :- (1) Do the manufacturers over there consider they get any engine smoothness from bearing caps held as on the "F" engine?. Going through all the sectional pictures of American car engines that we can find, we cannot see any evidence that they hold their bearing caps much better than we do. | ||