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).
Wallace-Barnes valve springs, their performance on Phantom models, and proposed design changes.
| Identifier | ExFiles\Box 66a\2\ scan0096 | |
| Date | 13th May 1929 guessed | |
| - 2 - Springs. We have been using Wallace-Barnes valve springs. These have been good for life. We have less than a dozen spring breakages on Phantoms in the whole country. But they have been very bad for irregularity and noise. We now have a new source of supply which on test has proved much better, but which we shall naturally suspect for a year or so. Hence our particular anxiety about the turbulent head design. Proposals. It does not seem possible to put any "safety ring" or pin on the valve stem which would not call for a lot of experimental work. We have only three proposals, the total effect of which might give fair safety:- (1) To spread the valve centers from 2.400 to 2.430. (2) To use the tighter-fitting guides as you have standardised (3) To change the chamfer at top of cylinder bore from .050 at 30° to .050 at 60°. We should greatly appreciate comments from yourself and Mr. Hives. Yours faithfully, ROLLS ROYCE OF AMERICA, INC. Maurice Olley r/ | ||