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 modifications to address vibration, covering crankchambers, flywheels, clutches, and balance weights.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan113 | |
| Date | 13th April 1931 guessed | |
| (2) This brings us to altering our P. 2. pattern of crankchamber at once even if we have to bolt an extension on existing crankshafts. In the meantime we must do something to existing chassis, and after testing the lightest flywheel we can use without other troubles and the stiffest back plate and flange, we can test the value of the larger crankpins, and of balance weights to my 8 weight scheme (which is the lightest, most practical, and most efficient, especially for this particular trouble) and if we cannot move it out of range we must go to the gearbox for help, at least in the original way that was found to have helped the 20HP. unintentionally. This would need cancelling the universal in the clutch and the fabric one could be fitted with steel discs that would permit a slight want in the alignment of the 3 bearings, but we must not theorise, but try if anyharm comes from the usual imperfections. This is rather a different way than has been tried: it may have some slight damping. If we still cannot keep the wheel steady some design of second bearing should be schemed even if it means some modification to other parts. These conclusions are arrived at by running up our engine on 18-EX. with the car standing, when definite periods can be picked out. The moderate speed one may be torsional, and the high speed one, which, even with no rear feet shivers one's spine when sitting in the driver's seat, is I think lateral. I very much regret to hear that Nothing was done for Mr. Iden whose car may have had a bad or difficult body, but evidently was unpassable as a complete car. His remark of the good period of 45 MPH. is correct and goes to prove that although piston inertia is great at this speed it struck no period of flexibility of either crankshaft torsion or flywheel support. My remarks of the hopelessness of the 6 cyl. are now modified. If we get a good 6 cyl. engine it may be quite the best for J.{Mr Johnson W.M.} 3. - see other memo. R.{Sir Henry Royce} | ||