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).
Continued memo discussing engine vibration characteristics, harmonics, and calculations.
| Identifier | ExFiles\Box 159\5\ scan0076 | |
| Date | 26th October 1940 | |
| - 2 - Cont'd.{John DeLooze - Company Secretary} 1. The amplitude of the 6/rev period. 2. The range over which one would expect it to extend. 3. Whether any of the other harmonics can be expected to be of sufficient amplitude to cause trouble. The calculations should be based on an engine of Phantom III bore and stroke, crankshaft dimensions and indicator diagram. We are a bit puzzled by your remarks about inertia of the Leyland parts having an effect upon their 6-cylinder engine 6/rev vibration, since we have always understood that the 6/rev vibration did not have an effect upon it. Having dealt with 4-stroke, we should like to know whether you would expect the situation on the flat-12 2-stroke to be any worse with regard to this particular 6/rev period. Personally I should, insomuch that the damping of the pistons which are not actually firing, would be only half that of a 4-cycle engine. Rm.{William Robotham - Chief Engineer} | ||