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).
Dispatch of automatic advance curves for the EAC.II and 20 HP engines.
| Identifier | ExFiles\Box 37\1\ scan 266 | |
| Date | 27th August 1924 | |
| x3949 SECRET To R.{Sir Henry Royce} from EPC. c. E.{Mr Elliott - Chief Engineer} c. CJ. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. EFC9/T27.8.24. AUTOMATIC ADVANCE - EAC.II. (AND 20 HP.) ENGINE. x3949 x9780 X-3485 Reference E1/M9.8.24. We are sending, addressed to R.{Sir Henry Royce} under separate cover, various curves. Group I, which is more immediate interest, comprises firstly two sheets of curves (originals) on 1" squared paper, one for 20 HP. chassis and one for EAC.2., and secondly, a number of tracings duly labelled in red. All the curves of this group are to the same scales of engine speed horizontally (1" = 200 r.p.m.) and of engine degrees vertically (1" = 4°). The pairs of curves on the squared paper represent the limits of ignition range as experimentally determined, over which maximum power is practically maintained at each speed, for each of the two engines, 20 HP. and EAC2. The figures from which the 20 HP. curves have been drawn were some figures determined by Hs.{Lord Ernest Hives - Chair}, dated 3.2.22. and the figures for EAC.2 have been determined by Hs.{Lord Ernest Hives - Chair} since the receipt of Mr. Elliott's note above referred to. These curves are plotted to a definite datum of top dead centre. Each of the tracings contains a pair of curves (one contains 2 pairs), and each one of a pair is the automatic advance characteristic of the unit in question. The two elements of each pair are separated by a vertical height representing in degrees the amount of hand advance obtainable (or specified) Contd. | ||