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).
Investigations into over-oiling problems with the Phantom III Valve Gear and proposing a new design for valve wedges.
| Identifier | ExFiles\Box 96\2\ scan0205 | |
| Date | 12th January 1937 | |
| Handwritten: Swdl.{Len H. Swindell} Can we get the true story of costs. Rm{William Robotham - Chief Engineer} Typed: Rm.{William Robotham - Chief Engineer} c.c. Sg.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} RHC.{R. H. Coverley - Production Engineer} HPS.{Horace Percy Smith - Experimental Factory Mgr} JNR.{Charles L. Jenner} E.5/HP.12.1.37. Phantom III Valve Gear. Referring to Rm.{William Robotham - Chief Engineer}2/R11.1.37, although we agree that recent investigations have given some useful results we are very much back to where we were in the beginning again. I refer to the fact that we tried originally to do without lubrication on the valve tip and found this impossible. We have again since endeavoured to prove that this lubrication was not required, and the final conclusion has been that we cannot do without the supply of oil. The nett result has been the evolution of a scheme for carefully metering the oil supply to the valve tip to avoid top over-oiling which in the words of the report is said to be almost cured by this scheme. It has been said that the cause of all the trouble is the presence of the gaps in the valve wedges which allow the oil to pass down the valve stem instead of being flung off by the top valve spring washer, and it is understood that it was proved that top over-oiling could be cured entirely either by cutting off the oil supply to the valve tip end of the rocker or by stopping up the gaps between the wedges with plasticine... It occurred to me that we might be able to make a practicable job of butting wedges which would seal off the offending passages, and after going into the matter at some length with Ws. he was of the opinion that it could be done without great expense. The scheme necessarily involved splitting the wedge to leave a full half and throwing away the useless portion. Dimensions for making these wedges are shown on LeC.5437 issued for some experimental sets to be made, on the 17th ultimo. We hope that this idea will be tried out as if it is found sufficiently practicable and confirms the results of the experiments made it should be a permanent solution to top-overoiling without the necessity for employing means to meter | ||