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).
Unbearable faults, including radiator shiver and engine vibrations, on a 20HP 12-G-4 Close Coupled Saloon.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan128 | |
| Date | 23th May 1929 | |
| HS.{Lord Ernest Hives - Chair} RY. } FROM R.{Sir Henry Royce} DH.{D. Henderson - Showroom} (struck through) C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} IN. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} (struck through) SECRET ORIGINAL R3/M23.5.29. X5770 X5830 (struck through) X5250 (struck through) 20HP. 12-G-4. (JAPAN.) CLOSE COUPLED SALOON. This car has several unbearable faults. (1) The radiator still jellies. One can only think that it has some relation to the body, which is a flexible one by Barker's, with rubber in the joints. It has not an underframe: I prefer one with. It should be removed from this chassis and another body of a more orthodox type fitted. It will be remembered that we have had the cross in the frame, and no cross, flexible and nearly rigid engine feet, but it has always had more or less the same shiver at the radiator. (2) Pistons are very much too heavy. I am inclined to think that the weight of these make themselves felt in some compound degree that is more than in direct proportion to their weight. In this particular instance they have brought the period down so that soon after 60 MPH. one imagines their entering the master period, and this in spite of the increased stiffness of the crankshaft, but it is also lowered by the old type crank-shaft damper. It is absolutely imperative to take every gramme of weight off the pistons, piston rings, and little end of the con. rod. In this particular case it does not seem as if the impulses were of first importance in setting up the torsional vibration, because it is so much more manifest on the overrun than at full throttle, both at just over 40 MPH., and just over 60 MPH. The 40 MPH. vibration appears to be an harmonic of the master period, in which the inertia impulses appear to be (1) | ||