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).
Preliminary tests and proposed modifications for the Phantom III solid rockers and non-hydraulic valve gear.
| Identifier | ExFiles\Box 96\2\ scan0231 | |
| Date | 1st June 1937 | |
| E.{Mr Elliott - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. Hs.{Lord Ernest Hives - Chair} c. By.{R.W. Bailey - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Mx.{John H Maddocks - Chief Proving Officer} 354 Rm{William Robotham - Chief Engineer}/Swdl{Len H. Swindell}5/R.1.6.37. PHANTOM III SOLID ROCKERS. Non-hydraulic Valve Gear. Preliminary tests have been carried out with the above valve gear (LeC5441) with promising results, which have also been confirmed on the road. It is early to say whether the valve gear will remain satisfactorily quiet over long periods of running, but in the meantime, however, there are various points in connection with this layout which should be modified. These are as follows:- (1) Oil drain from ends of the 4 port cylinder heads is not good. (2) Other than at the ends, the draining of the heads is an improvement over the standard 6 port heads in conjunction with the reduced amount of oil for the solid rockers in comparison with the hydraulic mechanism. The bottom spring coil, however, is partly submerged in oil, and if the bottom spring washer be lifted .150 the springs and washers would be clear of the oil. This appears to be possible without raising the valve gear, which would result in longer and heavier valves, and is not desirable on account of the necessity for stronger valve springs. In conjunction with the raising of the bottom spring washer, the top washer is raised so that the same valve spring is used. (3) As received according to design (LeC.5441) the oil hole at the push rod end of the rocker (.055 diam.) resulted in far too much oil for the push rods, and at low speeds dropped in a stream on to the valve springs. This we found much more satisfactory at .031 dia. | ||