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).
Stretching of exhaust valves on vehicle 29-CL and proposed design alterations.
| Identifier | ExFiles\Box 66\2\ scan0320 | |
| Date | 29th October 1928 | |
| S/W. Hs.{Lord Ernest Hives - Chair} X8230 CWB15/GM/29.10.28. 29-CL. STRETCHING OF EXHAUST VALVES. As you are aware, on the return of 29-CL. from a tour of approximately 4,500 miles, two of the exhaust valves were found to be considerably stretched, about twenty-five one-thousandths. On looking into the matter I find that there is a Standardisation Sheet, X. No. 7230 which proposes to thicken up the head of the exhaust valve and alter the diameter of the stem. I have also some recollection that when these thicker and therefore heavier valves were tried they were found to produce valve periods and that a further alteration was proposed on this account. The Standardisation Sheet referred to does not appear to have been signed by BJ., who requested a report of further tests before signing, which report does not seem to have been received. Would you please let me know how this matter now stands and whether the remarks on the Standardisation Sheet quoted, i.e. 'Road tests have shown present valves unsatisfactory' still apply. If they do not still apply, what alterations have been made to make them satisfactory? (CWB) (handwritten signature) CWB. | ||