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).
Investigation into the characteristics of an ignition governor and oil relay.
| Identifier | ExFiles\Box 66a\4\ scan0117 | |
| Date | 16th February 1926 guessed | |
| contd :- -6- of dealing with 27 lbs. due to the load required to operate the controls plus 10 lbs. due to the return spring. As we have shewn from our piston efficiency tests, an oil pressure of 15 lbs/sq.in. is insufficient to give the required result at 1000 r.p.m. The obvious alternative is to fit a magneto which is silent with less load on the sleeve, such a one is the Lucas which is at present being tested, or increase the effective piston operating area. Another possibility would be to alter the characteristic of the relay somewhat, and so overcome the trouble we point out in our observation on the relay's peculiarities. CHARACTERISTICS OF IGNITION GOVERNOR. We have been investigating the characteristics of the oil relay in its present form. We find that the power communicated to the large piston varies considerably. (a) With the relative positions of the small inner piston and the outer piston. (b) With varying engine speed. (a) To demonstrate the first perculiarity, a load considerably in excess of that which the relay could lift was placed on the top of the high pressure piston and the engine was run at 1500 r.p.m. The load was then reduced until the high pressure piston just lifted. This occurred in a specific case with 60 lbs.weight. The high pressure piston did not move, as might have been expected, through a large distance and take up a position where the oil was cut off by the small inner piston, but only lifted slightly. contd:- | ||