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).
Design recommendations for a Bentley high-compression cylinder head.
| Identifier | ExFiles\Box 86\1\ scan0119 | |
| Date | 7th February 1935 | |
| x219 To By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}27/KW.7.2.35. High Compression Head for the Bentley. We have run EB.2050 and it has given satisfactory results but we are apprehensive that we may get failure between the valves, as we have run a high compression head with similar valve centres and failure has occurred at this point. We therefore recommend that the head instructed for production should have the distance between the valves increased by .075" and the thickness of the metal from this point to the nearest water should be maintained as constant as possible. Furthermore, on EB.2050, trepanning was not carried out quite correctly. It should have been instructed with 2 arcs as shown on EX.16041 attached. This gives a better flow round the valve and should be incorporated. We consider that 1.3 exhaust valves are big enough. We of course require a 1.5 inlet. We presume that we can get the same increase in inlet port size as E.{Mr Elliott - Chief Engineer} is proposing to introduce on the silent tappet head which he is about to issue. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||