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).
Tests conducted on spark plugs, comparing Champion L.D.8 and KLG models for Bentley or 25/30 HP cars.
| Identifier | ExFiles\Box 162\1\ img042 | |
| Date | 22th September 1938 | |
| RM{William Robotham - Chief Engineer}/RC.{R. Childs}9/RH.{R. Hollingworth}22.9.38. RE PLUGS. Herewith results of tests carried out in co-operation with RM{William Robotham - Chief Engineer}/BR.{T. E. Bellringer - Repair Manager} on sparking plug operating voltages, in respect of which the Champion L.D.8, suitable for Bentley or 25/30 HP cars, comes out on top. We must, however, carry out further tests with respect to prolonged slow running before recommending, as a plug which runs only slightly too cool, will in extreme cases, cause elusive misfires. We are fairly confident with regard to electrode wear. Experience has shown that the sillimanite insulator of the Champion is not so strong as the corundite of the KLG; however, if handled with reasonable care, this is not detrimental to their use. RM{William Robotham - Chief Engineer}/RC{R. Childs}, | ||