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).
Development report on valve gear, crankshaft, and flywheel components, including for the Phantom III engine.
| Identifier | ExFiles\Box 161a\4\ scan0139 | |
| Date | 5th October 1936 guessed | |
| (3) Valve Gear. Development is in hand to see if it is possible to get a Phantom III engine sufficiently quiet without the automatically adjusting mechanism. This would have a number of advantages, and would leave considerable space available for increasing the size of the valve springs. An investigation is required on a valve gear rig to determine the actual lift curve relative to the theoretical to be followed by a development for reducing incipient valve bounce, and for reducing the valve spring pressure required with hydraulic tappets to hold off the incidence of ultimate valve bounce. An investigation is being carried out in connection with the trouble of top overoiling. A preliminary report has been issued, and the recommendations are being investigated by Design, and further conclusive tests have been indicated. Design department are producing a scheme for testing out 1/2" longer valve springs in carbon spring steel. Design department are also producing a modified cam form of smaller base circle diameter, with a view to avoiding the use of chromium faced tappets. This scheme also includes some cost saving modifications, and the altered cam form is required in connection with the valve spring durability experiments. A further development in connection with the last named is an experimental trial of a modified camshaft which should be made in the present large diameter type, but with modified cam form to reduce positive accelerations. An experiment should be made with half the number of oil feeds to the rocker gear detached and blanked off to see if the automatically adjusting tappets will operate satisfactorily in this way. This requires re-grading of the leak plugs to suit the single end flow in the rocker shaft. Crankshaft and Flywheel. Instructions for producing a crankshaft to the four balance weight scheme have been issued Lec.5230. This | ||