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).
Test results for an oil relay automatic ignition control system.
| Identifier | ExFiles\Box 65\1\ scan0022 | |
| Date | 11th December 1924 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} X8685 Hs{Lord Ernest Hives - Chair}9/LG11.12.24. OIL RELAY AUTOMATIC IGNITION CONTROL. X8685 We have completed a number of tests with the oil relay governor ignition control. We are sending you the best curve of ignition which we have so far obtained with the springs at our disposal. It will be observed that with the spring in question the rating is too high at low speeds and slightly too low at high speeds. We therefore cannot quite reproduce the specified curve with a spring of constant rating. We attribute this to the fact that the governor friction constant and the small relay piston stiction constant have more affect at low speeds where the dynamic couple of the governor weights is lower than at high speeds where the couple is about four times as great. We find that the two constants mentioned are appreciable. In spite of the apparent material discrepancy between the specified and observed curves, the power obtained under governor control was almost identical with that produced by manual adjustments of the ignition to find the best setting. In point of fact, .25 HP. was dropped at 600 and 750 r.p.m. .5 at 1000 r.p.m. The engine on which the tests were carried out was a 4 - 1 compression ratio. We have included a curve obtained with a contd :- | ||