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).
Phantom III valve gear tappet clearance figures under various operating temperatures.
| Identifier | ExFiles\Box 96\2\ scan0130 | |
| Date | 1st February 1936 | |
| To EH. c. to EG. c. to Moz. c. to Ey. c. to Da.{Bernard Day - Chassis Design} c. to MX.{John H Maddocks - Chief Proving Officer} Re/cwdl1.14/JB.1.2.36. Phantom III Valve Gear. In conjunction with the fitting of standard type of tappets and deleting the Hydraulic adjustment scheme the following clearance figures have been taken. (1) From a cold setting to reaching a water temperature of 80°C. as quickly as possible, the tappet clearance increases by .005". (2) By continued running until the oil temperature reaches 80°C., the clearance is reduced from an increase of .005" to .003". (3) Tests on KE.965 exhaust valves show that when running at high speeds full throttle the valve expansion is .007". (4) The combined result of (1) (2) & (3) means that in order that the KE.965 be definitely seated during prolonged full throttle work at high speeds, the necessary clearance setting must be. Cold Setting .004 Clearance when water quickly reaches 80°C. .009 " " oil reaches 80°C. .007 By substituting a/SV material for the exhaust valves the valve expansion is .005" in place of .007" with KE.965. This means that the above necessary clearances would be reduced by .002" throughout. | ||