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 curves for automatic advance on the EAC.II and 20 HP engines.
| Identifier | ExFiles\Box 54\5\ Scan274 | |
| Date | 27th August 1924 | |
| X3455 SECRET To R. {Sir Henry Royce} from EFC. {E. Fowler Clarke - Electrical Engineer} E. {Mr Elliott - Chief Engineer} A. {Mr Adams} C. EFC {E. Fowler Clarke - Electrical Engineer} 9/T27.8.24. c. E. {Mr Elliott - Chief Engineer} c. CJ. X.9249 X9780 X3455 AUTOMATIC ADVANCE - EAC.II. (AND 20 HP.) ENGINE. Reference EL/M9.8.24. We are sending, addressed to E. {Mr Elliott - Chief Engineer} 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" = 4º). 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 seperated by a vertical height representing in degrees the amount of hand advance obtainable (or specified). Contd. | ||