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 their probable causes during vehicle testing.
| Identifier | ExFiles\Box 80\3\ scan0097 | |
| Date | 14th October 1911 | |
| (3) experienced any trouble with valve springs breaking while cars were on test. These failures generally occured after at least 700 or 800 miles running. 3. This trouble was probably caused by the rotor being inaccurately set, and thus causing considerable sparking. 4. All valve springs fitted to cars with the increased lift on camshaft may give trouble by springs breaking. [Watermark: DICKINSON BOND CROXLEY 1804] R.R. 235A (100H) (W 935. 14.10.11) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2052 | ||