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).
The failure of plug leads in a 22 G.V. model, detailing causes and temporary solutions.
Identifier | ExFiles\Box 168\1\ img260 | |
Date | 26th June 1936 | |
HOTEL DE FRANCE. CHATEAUROUX. Indre. France. [Handwritten note top right] r6117 [Handwritten note top left] WST This seems serious. What do we propose to do about it? Rm{William Robotham - Chief Engineer} To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} [Typed document] GWH{George W. Hancock - Head Chateauroux}/LMW/4/JAB. 26th June 1936 22. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} V.{VIENNA} Failure of Plug Leads. The insulation of the plug leads has broken down, and the wires spark direct on to the valve rocker cover, and inside both the metal tubes through which they are led. There was also direct sparking from the main H.T. lead to this plug wires above the distributor. We attribute this to the following :- 1) Effect of under bonnet heat alone deteriorating rubber insulation. 2) Further effect of oil and paraffin on rubber. 3) Increased strain on insulation with use of wide plug gaps, and new distributor and coil. We do not think that causes 1 & 2 would have produced misfiring if the wires had not been enclosed in metal tubes and brought out close to the hot valve cover. In fact we have overcome the trouble temporarily by using the same wires bound together with tape and discarding the tubes. Cause 3 is borne out by the fact that a continual blue discharge is visible down the plug insulators at night. --------- GWH{George W. Hancock - Head Chateauroux}/LMW. | ||