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).
Investigation into a fuel system ignition issue, detailing potential causes and proposed modifications.
| Identifier | ExFiles\Box 3\6\ 06-page176 | |
| Date | 11th May 1934 | |
| - 2 - E.1/HP.11.5.34. If any part of the fuel system should come adrift it should be rendered impossible for the fuel to be ignited. In this respect we do not believe that Mr Baring's car was necessarily set alight by the distributor as reported by GWH.{George W. Hancock - Head Chateauroux} The fact that this part was damaged externally by fire is not evidence of this, as in cases of petrol fires which have been investigated it has generally been found that ignition has occurred from a distance due to the gas mixture flashing across from some naked flame. The interior of the ignition tower moreover was very clean. We therefore still suspect the sparking plug terminals which may have sparked in three ways:- (a) Between central electrode and cable eyelet. (b) Between spring wire clip and induction pipe. (c) Along outside of insulation due to condensed moisture. (a) and (b) will be dealt with immediately by the change to spring washers and milled nuts. With regard to (c), we think this will be eliminated in the course of time by the development of an enveloping terminal on the end of the H.T. conductor which covers in the plug. We have some of these instructed for the SpectreCodename for Phantom III, where we have ignition plugs and carburettors in the Vee. Summarising the position then as it stands at the moment:- (1) The S.U. Co. will rectify the induction system to avoid escape of fuel if floatchambers flood. (2) The flooding device will be retained but should be improved. (3) The float needle guide will be improved to render it less liable to jam. (4) The plug terminals will be altered in the manner already arranged. In respect to (2) and (3), we will send our suggestions to the S.U.Co. E.{Mr Elliott - Chief Engineer} | ||