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).
Comparative tests of various sparking plugs to withstand over-oiling and sooting.
| Identifier | ExFiles\Box 162\6\ img097 | |
| Date | 1st March 1926 | |
| SPARKING PLUG TESTS. Comparative tests with regard to the ability of various types of plug to withstand over oiling and sooting. Tests were carried out on 44RK. Oil was admitted to the induction pipe and the car run at 10-15 m.p.h with the starting carburetter partly in operation, the engine being allowed to run on as rich a mixture as possible without actual misfiring. Each type of plug was tested against the Lodge non detachable C type plug in every cylinder. As a basis for comparison the Lodge non detachable C type plug is taken as 100% plug as regards its ability to withstand oil. Lodge C Type non detachable 100% Lodge C Type detachable (present standard) 105% Lodge C 150 Type detachable 122.75% Bosch 2RD Type non detachable 107.5% These results show the superiority of the latest type Lodge detachable plug, marked 'C 150', which type of plug it is recommended should replace the present-standard C Type detachable plug. Plugs of the 'C 150' type when run in a test bed engine do not show any marked tendency to preignite or overheat excessively. A.F.Sidgrey | ||