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).
Tests conducted on the valve bounce phenomenon in the F.10 engine.
| Identifier | ExFiles\Box 42\3\ Scan062 | |
| Date | 13th December 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} X5841 Hs{Lord Ernest Hives - Chair}/ACL1/LG13.12.26. F.10 - VALVE BOUNCE. 43022 We have made some tests in connection with the inlet valve bounce phenomenon which is manifest at the higher speeds on F.10. Although up to the time of writing the experiments have not revealed a definite reason for the difference in performance between the inlet and exhaust valves, they have shewn that the trouble is not appreciably influenced by the type of manifold employed or the valve timing that can be obtained with the standard camshaft. The tests were made with the triple valve springs - LeC.2281 - and the Claudel carburetters in the Vee were used on the 6-cyl. F.10. The valve motion at speeds between 2250 and 2400 r.p.m. was studied by means of the oscilloscope. What we have observed to happen is as follows :- The roller and valve follows the cam contour over the whole lift period but when about half way down on the lower-ing period the roller is seen to leave the cam. It returns and strikes the cam approximately at the commencement of the base circle and rebounds as far as we could judge somewhere about 1/16". The diagram given is what appears to be the motion of the roller relative to the cam. We next tested the effect of a 6-cyl. manifold - the continuous pipe with a carb. at each end - and could contd :- | ||