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).
Addition to a report on silent tappets, detailing two experienced troubles and suggesting alterations.
| Identifier | ExFiles\Box 106\5\ scan0086 | |
| Date | 20th March 1933 | |
| E.{Mr Elliott - Chief Engineer} ) from Hs{Lord Ernest Hives - Chair}/Std. BY.{R.W. Bailey - Chief Engineer} ) c. to RHC.{R. H. Coverley - Production Engineer} X1060 Hs{Lord Ernest Hives - Chair}/Std.8/KT.20.3.33. ADDITION TO REPORT ON SILENT TAPPETS - 6.3.33. Since this report was made the engine fitted with these tappets has been used for carburetter development work, and some trouble with the tappet gear has been experienced. Two troubles were experienced :- (1) Locking nut on tappet adjusting screw came loose and eventually fell off, allowing the adjusting screw to work loose. This was probably due to the nut not being sufficiently tightened, but the arrangement is not satisfactory at present owing to the fact that the nut only engages with about 3 threads of the adjusting screw, as the push rods are not quite long enough. (2) One of the plungers seemed to be leaking badly, and on investigating this proved to be due to the disappearance of the small copper locking ring in the groove at the end of the plunger valve - the valve being thus allowed to fall to the bottom of the plunger barrel thus putting this tappet out of action. This ring was replaced by another thin piece of copper wire and is now working satisfactorily. Both these troubles indicate necessary alterations - these are suggested below :- (a) The push rods must be increased in length or else the adjusting screws must be lengthened - so as to obtain a full thread in the adjusting nut. (b) An improved locking or stop device at the end of the plunger valves instead of the present copper rings is necessary - these are difficult to fit and unless they are the correct thickness will push over the valve end as in the case experienced. Hs{Lord Ernest Hives - Chair}/C.S.Steadman. | ||