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).
Complaints on engine vibrations, dynamo output, and ignition systems.
| Identifier | ExFiles\Box 181\M13\M13.2\ img030 | |
| Date | 26th January 1931 | |
| -2- Engine Booms and Vibrations. This is a very definite complaint and one which limits us with the 25 HP. car. We are committed to a six cylinder engine and we expect the design to continue for a number of years. We have got to anticipate engine speeds up to 4,000 R.P.M. Other people are doing this now. Tests recently have shewn that if we are going to run high speeds we must control the flywheel better than we do at present. Having the engine gears at the rear should, as you point out, give us extra bearing and we believe this is the most practical way of controlling the flywheel; it is what the Bentley and others do. Higher engine speeds will definitely demand balance weights in order to obtain reasonable life out of the bearings. Bearing life may also make it necessary to use a hardened shaft. The crank proportions will have to be such that we shall be clear of the master period at the high speeds. The proposed new stiffener each side of the crankcase should be a definite improvement. We know that the modified flywheel has proved to be an advantage. However successful we are in improving the engine smoothness we have still got to anticipate the flexible engine mounting, even on the twelve and sixteen cylinder Cadillacs this has been found necessary. The most satisfactory scheme is where the unit is supported on trunnions at each end with light torque arms each side and torque re-action dampers at the front. Using the above features we think it is possible to make a six cylinder engine which will run fast and be free from any objectionable vibrations and booms. Dynamo Output. This is another complaint which shews up on the Quarterly List. We feel that it would be better to have a machine which normally supplied sufficient current at something below its maximum output. Ignition Complaints. We greatly favour making this car with complete twin ignitions. That is, twin battery ignition distributors and two plugs. I am sure it would make it much more attractive and we doubt whether it would be any more expensive than the present scheme of carrying magneto. Our troubles on ignition have been mostly coils but these, we believe we are getting over, and with twin ignition sets the car should be absolutely reliable. | ||