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).
Oil pressure specifications and operation for Phantom oil relief valves.
| Identifier | ExFiles\Box 66a\4\ scan0023 | |
| Date | 22th November 1926 | |
| To Mx.{John H Maddocks - Chief Proving Officer} from Hs{Lord Ernest Hives - Chair}/AJL. c. EY. X8205 Hs{Lord Ernest Hives - Chair}/AJL1/T22.11.26. RE PHANTOM OIL RELIEF VALVES. Mx{John H Maddocks - Chief Proving Officer}/Mcm7/T17.11.26 An oil pressure of 5 lbs/sq." to the rocker shaft is quite in order on the chassis, we do not consider it excessive. The figure of 1.25 lbs/sq." given on the drawing applies to the test rig only, and also when the valve is tested independently of the other valves as stated on the drawing. On the rig this valve is tested under a comparatively small oil flow to start to pass oil at 1.25/lbs/sq." pressure. When on the car, and all three valves are in position and a larger oil flow is used, the pressure given by this valve is greater owing to - (a) the presence of the low pressure valve given by which is added to the pressure given by the rocker shaft valve, and (b) is greater due to the increased lift and consequent increased valve spring load caused by a large oil flow. Thus the actual pressure obtained is made up as follows :- Pressure given by rocker shaft valve alone = 1.25, plus the " " " low pressure valve = 1 lb/sq.", plus the increase given by the larger oil flow than on the rig, bringing the total up to 5 lbs/sq." If it were intended to obtain only 1 1/4 lbs/sq." to the rockers, there would be no need for a separate relief valve, the present low pressure valve would control the two feeds. Contd. | ||