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).
Manifold experiments and body noise testing related to chassis vibration.
| Identifier | ExFiles\Box 17\7\ Scan033 | |
| Date | 10th May 1929 guessed | |
| contd :- -5- Regarding the manifold we made one up from welded steel with an expansion box on the lines of the old Silver Ghost, as in sketch -(SEE ORIGINAL FOR SKETCH) but although this was thought once to effect a slight improvement it did not alter the booming noise which recurred when the throttle was opened. There are 3 manifolds available for experiment - the original type in thicker larger staybrite tube Lec.2657, the one above, and the cast iron Lec.2638. The last named is thought by Mr. Hancock to be the most silent, but owing to the complication introduced by different engine mountings none of these exhausts have been compared yet on equal terms. All three are being taken to Le CanadelHenry Royce's French residence to shew R.{Sir Henry Royce} BODIES. The whole of the testing mentioned herein on SS.{S. Smith} was done with closed bodies, as these are naturally the worst for bringing up radiator joggles. When the body is lifted off the chassis on the bump test the periodic effect disappears, and is also partly eliminated by single point mounting the front of the body, but this latter renders the steering uncertain. The head lamps have a period of their own which sometimes shews up when the front of the chassis is otherwise quiet. It should be remarked that in the tests with the so-called degutted frame scheme (b) nothing was used in the place of the X. frame member, but it is not anticipated that the tubular cross members now being added on the chassis that is to proceed to Le CanadelHenry Royce's French residence will materially affect the results. E.{Mr Elliott - Chief Engineer} | ||