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).
Technical improvements for the E.A.C. engine regarding compression, smoking, ignition and the starting handle.
| Identifier | ExFiles\Box 72\4\ scan0121 | |
| Date | 9th February 1924 | |
| X9770 SECRET. R3/M9.2.24. To HS.{Lord Ernest Hives - Chair} RG.{Mr Rowledge} } FROM R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} } c. to CJ. BJ. Wor.{Arthur Wormald - General Works Manager} PN.{Mr Northey} BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} E.A.C. ENGINE. X.9770. Many thanks for your report (1.2.24) of the above with suggestions. COMPRESSION. X.790. I certainly agree that the lower 4.3 will be preferable; fuel in France makes an engine detonate much worse than the English supplies, where also you can use part benzol until better fuels are more universal. We must carefully keep a clear of detonations, and incidentally keep a smoother engine. SMOKING. One of the very chief advantages we have over the sleeve valve people (who may equal us in silence and beat us in absence of detonations) is we can beat them definitely in absence of smoke and oil consumption, so we must make a point of getting this right. I quite agree to the stiff and wider ring with narrow bearing surface. IGNITION. X.9790 X.9780. Evidently ungoverned magneto will spoil this engine both in getting away after luffing up, detonations, and slow running (light). You will remember that we also found at WW. that on Goshawk good slow running could only be obtained when spark occurred on top dead centre. If before or after it more often failed to ignite the charge; but here is a point - does it make any difference if there are 2 sparks (i.e. double ignition) if one is before, as long as one occurs at top dead centre? (I only refer to slow running; no load). It seems we must have governed magneto or arrange to run with battery only, and supposing we can get no other we must use Scintilla. I quite think you will find this well made and reliable. Renault use automatic advance magnetos. STARTING HANDLE. X.9270. Re. positions due to 2 or 3 1/2 jaws, since it is to be so rarely used, and other people (Marmon) are content with 2 jaws we thought we could use this less costly scheme. Will RG.{Mr Rowledge} and E.{Mr Elliott - Chief Engineer} settle this with Hs.{Lord Ernest Hives - Chair} I am agreeable, but I think to make a real job of getting into a correct position for all ways of handling 6 jaws will be needed so you can pick any of the 60°, otherwise all three may be in an equally bad position unless carefully timed for a method of handling, and also relative position on engine, and on the starting handle - (present 40/50 has 6 positions, I believe). R.{Sir Henry Royce} | ||