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, specifically radiator vibration and heavy pistons, in a 20 HP Close Coupled Saloon.
| Identifier | ExFiles\Box 5\2\ 02-page274 | |
| Date | 23th May 1929 | |
| 45830 Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} R3/M23.5.29. c. to DA.{Bernard Day - Chassis Design} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} 20 HP. 12-G-4 (JAPAN) X.5770 c. to PN.{Mr Northey} C. CLOSE COUPLED SALOON. X.5830 X.5250 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 six joints. It has not an under- frame - 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 com- pound degree that is more than in direct proportion to their weight. In this particular instance they have brought the period down so that none after 80 m.p.h. 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 conn, 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 m.p.h., and just over 80 m.p.h. The 40 m.p.h. vibration appears to be contd :- | ||