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).
Valve gear rocker geometry and an experimental setup on a Phantom engine.
| Identifier | WestWitteringFiles\R\January1928-March1928\ 118 | |
| Date | 7th March 1928 | |
| HS.{Lord Ernest Hives - Chair} FROM E.{Mr Elliott - Chief Engineer} C to BJ. R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} [crossed out] ORIGINAL! EAC.10. VALVE GEAR ROCKERS. Our present standard practice as regards the geometry of valve rockers is to arrange the rocker pivot about 1/3rd of the travel below the top of the valve stem, so that the minimum of scrub is occurring at the time of maximum load. The practice last recommended by the Exp. Dept. was to place the pivot level with the top of the valve stem so that the minimum of scrub occurred at the moment of the valve being seated. This was said to cure valve noise caused by the valve approaching its seat out of line. To prove the value of this recommendation a scheme of vertically guided tappets was drawn for trial on a Phantom - LeC. 2411. -in which the rockers operated on well fitting vertically controlled tappets. We should be glad to know if you have arrived at any conclusions from the experiment so that we can decide what should be done on EAC. 10. E.{Mr Elliott - Chief Engineer} | ||