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).
Issue with a high-speed battery ignition cam for Spectre and Bentley models.
| Identifier | ExFiles\Box 163\7\ img236 | |
| Date | 4th January 1934 | |
| WST See me #S To Sg.{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} 86120 E.3/HP.4.1.34. c. Wcr. By Hs.{Lord Ernest Hives - Chair} Hs{Lord Ernest Hives - Chair}/Wst. High Speed Battery Ignition - SpectreCodename for Phantom III and Bentley. Referring to Sg.{Arthur F. Sidgreaves - MD}18/E.2.1.34, I would like to make it clear that there was no cam to LeC.3323 which had been wrongly designed and gave poor high speed characteristics. Actually the cam specified on LeC.3323 was the Delco Remy but by some mistake in the instructions it was put on the wrong way round, and as the cam form is assymetrical the result is bound to be as found. It was at this stage that we produced the first ignition cam designed on the same mathematical basis as used for the engine valve gear cams. With regard to the present battery ignition used on 20/25 and Phantom, although this is fitted with a cam having a form which is a geometrical approximation, ananalysis shows that this cam can be very little improved upon for the conditions under which it operates without altering the breaker gap, and we do not advise any modification to this, and should prefer to rest content until such time as we adopt the double breaker type as used on the Bentley. E.{Mr Elliott - Chief Engineer} [STAMP: RECEIVED ... 1934] | ||