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).
Methods to reduce engine detonation and material considerations for exhaust valves.
| Identifier | ExFiles\Box 158\4\ scan0272 | |
| Date | 7th December 1938 | |
| 1360 Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} from Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}5/R.7.12.38. EXHAUST VALVES. In view of the incipient detonation which still appears to exist on this cylinder head, we should like to urge the single cylinder parts, as with them we should be able to try such difficult modifications as moving the spark plug position and trying the effect on detonation, measuring their results by means of an indicator. With regard to exhaust valves, we believe we can still try close-clearance valve stems with an oil jet on the valve stem. With the object of reducing detonation, we could also try a jet of oil directed on the under part of the piston where detonation takes place. We will try these experiments when we have run another 10 hours similar to the six already carried out, only richening up the mixture, so that we are sure we are not running over weak on any cylinder. With regard to the cost, we understand from Banks' paper that 'Brightray' is cheaper than 'Staybrite', and should like to find if this applies to our car exhaust valves, if so, we should use 'Brightray'. We, also understand that Silchrome No.1 makes very good inserts, and we ought to try this if it is cheaper than 'Brico'. Rm.{William Robotham - Chief Engineer} | ||