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).
Valve spring failures and fault analysis for chassis 2100E.
| Identifier | ExFiles\Box 80\3\ scan0137 | |
| Date | 4th December 1912 | |
| TBB26/L41212 December 4th 1912 Report on Special Parts fitted to Chassis 2100E. 26. VALVE SPRINGS :- These are of the taper design but I regret to report we are having a considerable number of breakages on the running rig. 9 have failed out of 120. We have tried bouncing valve springs on a stone floor and listening to the note given out, one occasionally finds a spring which gives practically no note and sounds more like lead. We went through a batch of taper valve springs and selected 3 which gave a poor note and ran them on the rig, one of these was broken after 15 hours, but the others have stood up alright. Unfortunately this is not very conclusive because we also selected 6 springs which gave good notes and one of these failed after 50 hours. There appears to be two kinds of faults in these springs, one is a longitudinal flaw which often occurs in the centre of the spring and occasionally reaches to the circumference and shows itself by a line running a considerable length of the spring. The other kind of flaw is a crack starting from the outside. When a spring is bounced and rings badly, if this spring is broken it generally shows an internal | ||