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).
Memorandum about a discussion with General Motors regarding issues with hydraulic silent tappets.
| Identifier | ExFiles\Box 173\2\ img296 | |
| Date | 12th March 1934 | |
| SGW OR RGE By Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} #/KW233 34 Hs.{Lord Ernest Hives - Chair} SILENT TAPPETS 12/3/34 I saw G.M. about our Hydraulic Tappet difficulties today. 1. They have never been able to make this work with a ball valve. They tried before adopting the poppet valve type and went back to the ball again after succeeding with the poppet valve but the result still unsatisfactory. Symptoms occasional breathing such as ours, attributed to lack of clamping of the ball which lets it fidget on its seat. Also ball not coming down squarely. If they guided the ball they found it liable to jam in the guide. 2. The hydraulic tappet has forced them to make better valve gear because it shows up valve spring surge or incipient bouncing, by holding the valve off its seat as in our case. 3. Dirt in the oil has been a prolific source of trouble. 4. They agree with us that most of the noise in the valve gear comes | ||