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).
Technical notes on silent tappets, discussing Cadillac's advice and the Wilcox-Rich lifter.
| Identifier | ExFiles\Box 173\4\ img170 | |
| Date | 16th December 1935 guessed | |
| Silent Tappets Cadillac advised us to leave Groove with the valves being held open on a slow opening unless we have at least 1/16" from plunger clearance. Their production test is to try the rate of fall of the plunger under a given load because in the limit of a self-perfecting bearing and push rod deflection can cause noisy operation. When cranked slowly with the oil, valve slowly opens then there is on a the tappet cover no lift for the first... The new Wilcox Rich lifter had built on the camshaft a few grooves from Groth, provided it has air free oil. They found that a groove too soon is wrong, after the valve closes meaning the oil pressure fell from 40 lbs to 4 lbs in the air on the oil immediately expanding and preventing the tappet working. They now have a valve to close the tappet oil circuit fully when shut off or have all the oil to mix in the engine. The bearings sometimes running up to without any oil. | ||