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).
Instruction sheet detailing the testing and failure rates of valve springs.
| Identifier | ExFiles\Box 80\3\ scan0228 | |
| Date | 10th June 1912 | |
| R.R. 238 (24 F) (I.L. 255. 10.6.12) E.P. 1997. ROLLS-ROYCE LIMITED. INSTRUCTIONS. 19 To Order No. II Customer's No. Valve springs The % of breakages is quite as high as the standard parallel spring. We have had 4 breakages on the rig out of 72. & altogether we have had 9 faulty in 120. We have run two sets of the old type again lately with no breakages. We also went through about 150 of them with the bouncing test & could not find one faulty by that means. We have bounced about 50 taper ones & found 3 with flaws. The most convincing test is that two broke on the test engine when it was running 10,000 normal speeds, these are the two first valve springs which have ever broke on this engine or on any other engine. Every taper spring that has broken has shown a flaw. I consider the inspector should make use of the bouncing test as it does help the job. Signed MAH This Sheet must be filed on completion of the work. | ||