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).
Letter to Cadillac discussing sparking plug suppression, idling performance, and experiments with hotter plugs and shielded systems.
Identifier | ExFiles\Box 58\2\ Scan162 | |
Date | 26th October 1934 | |
Y1812. Hs{Lord Ernest Hives - Chair}/Wst.6/MA. 26th October, 1934. E.K.Schadt, Esq., Electrical Engineer, Cadillac Motor Car Company, Detroit, Michigan, U.S.A. Dear Sir, Mr.Robotham has passed on to me the information which you gave to Mr.Olley, and the same is of considerable interest to us with regard to sparking plug suppression. We have definitely proved that the idling performance on our cars is impaired when these suppressors are used and we do not consider that closing the sparking plug gaps will help in fact our usual experience is the reverse. What we propose to do is to try a sparking plug with electrodes which tend to run slightly hotter in order to prevent carboning up of the electrodes which we find is a common complaint when suppressors are fitted. Designing the plug with electrodes running hotter should prevent the formation of carbon and reduce the working voltage of the sparking plugs and thus improve idling. We are experimenting with a completely electrically shielded system, i.e. metal braided cables and shields, distributor and coils. This of course greatly increases the capacity component of the sparking its dis-advantages being, however, that the capacity loading on the ignition coil is greater and the wear of the sparking plug points and distributor points is also slightly greater. | ||