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).
Progress report on tests concerning the chassis, starter, exhaust system, and shock absorbers.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan064 | |
| Date | 24th January 1929 guessed | |
| contd :- -2- at different points along the frame. We have not been successful with this in making the chassis bad, we have therefore come to the conclusion that it is the moment of inertia of the body, and we are confirming this by tests. We have got to the stage when 20-EX car is definitely better than 19-EX (the car you are running) and it is only when travelling at high speeds over a bad road that one can pick out this fault. All work in connection with this is progressing favourably and we have no doubt that a satisfactory compromise will be arrived at shortly. (2) Starter. Recently we have had a good spell of cold weather. We have left an SS.{S. Smith} car out all night under these conditions and we are satisfied that the modified starter motor has ample power to turn the engine under these conditions. (3) Exhaust system. Our tests are confirming your views, that the most satisfactory way to reduce the noise is to split up the length of pipe. We fitted to one car a Phantom silencer and front expansion chamber. We led the exhaust pipe in at the front end of the expansion box so that it formed a continuous length of pipe. With this scheme the noise was just as bad as the original Phantoms. By arranging it as suggested by you the exhaust noise is greatly reduced. It also reduces the noises with the cutout open. The tests have gone far enough to shew that a solution to the exhaust noise is not far distant. (4) Bump tests. We have completed a 100 hrs. bump test on the front and on the rear of the SS.{S. Smith} chassis. Except for shock absorbers we have had no major failures. Tests on the modified shock absorbers are in progress and there is no doubt contd :- | ||