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).
Issues with pinned valve tappets, proposing improved manufacturing accuracy as a solution.
| Identifier | ExFiles\Box 158\4\ scan0004 | |
| Date | 20th November 1919 | |
| X. 3733. To E.{Mr Elliott - Chief Engineer} from Bn.{W.O. Bentley / Mr Barrington} Copy to CJ, Da{Bernard Day - Chassis Design}, Hs{Lord Ernest Hives - Chair}, EP{G. Eric Platford - Chief Quality Engineer}, BY, CK.{Mr Clark} Bn{W.O. Bentley / Mr Barrington}8/W11219. X.3733. - RE PINNED VAVLE TAPPETS. E With reference to DA{Bernard Day - Chassis Design}(?)?/G20.11.19, our impression is that the variation in clearance obtained when the tappet is turned round is due almost entirely to faulty machining. Cases have been found in test cars in which the clearance has been affected as much as .003 inch. We think further consideration should be given to this matter before we return to the pinned type of tappet as this latter type has disadvantages. Apart from the objection that chauffeurs use the pinning as a means of holding the tappet while adjusting (this we consider undesirable, but not very serious). Some trouble was originally experienced owing to the slots wearing and the pin actually causing some noise in the slot. We think the better policy would be to improve the accuracy with which these parts are manufacture. Will you please put this matter before Mr. Royce and advise us whether he approves of this procedure. Bn.{W.O. Bentley / Mr Barrington} | ||