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).
Tests on experimental cars to address Phantom III engine roughness by altering balance weights and crankshafts.
| Identifier | ExFiles\Box 91\1\ scan0484 | |
| Date | 4th March 1937 | |
| 300 E.{Mr Elliott - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. to Hs.{Lord Ernest Hives - Chair} c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/Gry{Shadwell Grylls}5/R.4.3.37. P.III ENGINE ROUGHNESS. On 33-EX car we have recently reduced the amount of balance weight so as to give 62% balance, i.e., the same amount as on the Bentley. We did this to see whether the increased bearing loads by virtue of more internal damping would lessen the magnitude of the torsional period. Even with the large crankshaft damper this period is still objectionable if the driver keeps his foot on the clutch pedal. From the test on this car, the reduced amount of balance did not appear to affect the torsional period, but it was thought that the engine had become generally rougher at high speeds. On 37-EX we have now tried the original Packard type of crankshaft. This again had no affect on the torsional period, but the engine was as smooth at high speeds as with the standard arrangement. The Continental engine is fitted with the lightened Packard type crankshaft, which we shall standardise if successful. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||