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).
Engine component performance, detailing issues with valve bounce, gear failure, and lubrication.
| Identifier | ExFiles\Box 123\5\ scan0104 | |
| Date | 30th September 1938 | |
| -4- Rm{William Robotham - Chief Engineer}/Swd1.9/MH.{M. Huckerby}30.9.38. rocker pad at right angles to the valve at half lift as against the present arrangement of being square in the valve closed position. Valve bounce with wraith springs (EB.3256) occurred at 3500 r.p.m. on the inlet valves and by fitting stronger springs Rs.{Sir Henry Royce's Secretary}540 with Km.400 top washers one short run up to 4000 r.p.m. was obtained without any obvious bounce. The rotation of the tappets was erratic; however, the condition of the bottom tappet faces are without exception excellent. Gears. We have not specifically listened to the gears but they cannot be noisy, otherwise would have been noted during the general running. There are signs of the harmonic damper fidgeting on the crankshaft taper, however, the damper loading which is controlled by the leaf springs is too high and is being reduced for subsequent tests. Distributor drive gear failure. The camshaft and integral distributor and oil pump drive gear which failed was made in cast Monichrome material, the failure being through excessive wear. This material appears excellent for the cam forms, but it looks as if a lot of investigation work will be necessary to obtain a satisfactory gear. In order to get on with the main development of the engine, therefore, we have instructed for future camshafts in the normal S/2N material, with the possibility of coming back to Monichrome later on. This material has a very appreciable advantage with regard to cost saving and consider it worthy of further work. Lubrication. So far, judging by the condition of the parts after our preliminary running, all the working parts appear to have been satisfactorily lubricated. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||