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).
Letter to Rudge-Whitworth Ltd. regarding breaking exhaust valves on a 500 c.c. 'Ulster' Rudge engine.
| Identifier | ExFiles\Box 133\1\ scan0044 | |
| Date | 7th May 1936 | |
| X1129 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Ed.{J. L. Edwards}16/KW. 7th May, 1936. Messrs. Rudge-Whitworth Ltd., COVENTRY. For the attention of Mr. Hack. Dear Sirs, With regard to the 500 c.c. "Ulster" Rudge engine in our possession, we have for some time been experiencing trouble due to breaking exhaust valves. The matter was investigated, and the trouble was ultimately put down to fatigue cracks starting at tool marks. The valves were accordingly given a mirror finish before fitting, and it was also decided to run two sets of valves, chalk testing those not actually running. Despite these precautions, a further fracture has occurred, this time while running boosted to 4" Hg. 70° boost air temperature and at 4000 r.p.m. We should like to know whether similar trouble has occurred with you, and if so, what steps have been taken to rectify the matter. On some of the valves, slight undercutting at the radius is observable, and this may have some effect. Also we should be glad if you would let us have an analysis of the steel used for those valves. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||