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 bounce issues and solutions for the Large Bore 25.HP engine.
| Identifier | ExFiles\Box 106\5\ scan0151 | |
| Date | 2nd January 1936 | |
| To RHC.{R. H. Coverley - Production Engineer} X554 Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}4/JH. 2.1.36. Large Bore 25.H.P. Valve bounce was experienced on C.16 unit at 3850.RPM and confined to the inlet valves. By substituting the existing 25.H.P. springs E.60420 by Bentley Springs EB.175 thus increasing the seat loading by 5 lbs. we were enabled to reach approx. 4000 RPM. before bounce occured: At the present time the wedges in the inlet spring cap come .075 below the cap face. A request was made to By.{R.W. Bailey - Chief Engineer} to detail valve wedges that would come flush with the spring cap face as is the case with the exhaust. These wedges are to E.60824, and should be fitted to C.15, and C.16 units, at the same time the EB.175 springs should be replaced by 25.H.P. springs E.60420. Hs{Lord Ernest Hives - Chair}/Swindall. | ||