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).
The comparative endurance testing of valve springs, including a proposed American design.
| Identifier | ExFiles\Box 41\1\ Scan085 | |
| Date | 23th August 1923 | |
| Y3777 R.{Sir Henry Royce} HS.{Lord Ernest Hives - Chair} EE. BY2-P23.8.23. VALVE SPRINGS. In connection with the American proposal to reduce the number of coils in the valve spring, we put this on our standard valve spring test rig. Our own valve springs (set of 12) have run 215 hours continuously night and day, with a failure of only one spring, which failure is due to a distinct fault in the steel. The fault in question was a peculiar one and we are investigating same to bring the matter before Messrs. Firths attention. The American type 9 coil spring broke in 13 hours, running under the same conditions. In this case there was no sign of a flaw in the steel, breakage appearing to be due to over-stress, resulting in fatigue. We are carrying on with the test to see whether we shall have further failures at an early date. BY.{R.W. Bailey - Chief Engineer} | ||