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).
General information memo on battery ignition issues, focusing on spark plug sooting and high-tension wiring.
| Identifier | ExFiles\Box 58\3\ Scan031 | |
| Date | 20th November 1919 | |
| X.1918 B. R2/G20.11.19. To EH. from R.{Sir Henry Royce} Copy to CJ. " " BN.{W.O. Bentley / Mr Barrington} " " EP.{G. Eric Platford - Chief Quality Engineer} " " HM.{Capt. W. Hallam - Head Repairs} " " PN.{Mr Northey} " " H.{Arthur M. Hanbury - Head Complaints} " " OY. X.3413 X.3129 X.3414 RE BATTERY IGNITION. (FOR GENERAL INFORMATION.) I understand we are altering chassis high tension wiring as soon as possible, because experiments shew high tension conductors in earthed metal tubes definitely detrimental to battery ignition. We have found that porcelain ignition plugs like the Lodge, and in the old days the Pognon, get so hot in the porcelain as to prevent the accumulation of carbon, and therefore keep clean and continue to fire, whereas some of the somewhat superior plugs as used in the aero engine practice, remain so cool in ordinary car practice as to accumulate soot sufficient to make the ignition work somewhat unevenly at certain speeds. We have therefore been obliged to use at least two porcelain plugs on the battery ignition in cylinders Nos. 3 and 4, because these occasionally during starting or running cold or priming, have a tendency to soot more than other plugs. Metal tubes were used to obtain a neater arrangement of wiring than our pre-war chassis wiring, which was in separated fibre tubes. This was the only scheme we could find that was suitable for our pre-war trembler ignition. The above was not the real cause of the slight failure of our battery ignition, which was due to slowly sooting up of K.L.G. plugs. R.{Sir Henry Royce} | ||