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 performance and wear of different types of spark plugs.
| Identifier | ExFiles\Box 97\5\ scan0190 | |
| Date | 31th May 1939 | |
| -5- Rm{William Robotham - Chief Engineer}/RC.{R. Childs}2/JH.31.5.39. material remains hard at all temperatures, no movement will be possible between the two windings. Sparking Plugs. We have received the following plugs and report from Rm{William Robotham - Chief Engineer}/lm. Type. Mileage. Remarks. 6 - Champion L8S 5,934 One broken when removing wear .007" - .008". 1 " 26,366 Broken when fitting. 1 " 26,366 Insulator button broken away. 4 " 27,869 Electrodes worn but still serviceable. 2 K.L.G.VLB.30.X. 1,400 Central electrode on one plug broken off. Wear on other .007". From the above it is evident that the K.L.G. plugs have a more rapid rate of wear than the Champion. This is due partly to the fact that the Champion is a shade cooler. We have tried a cooler K.L.G. plug (F.B.30.X.) without success. We are still of the opinion that the Champion L8.S plug is the most suitable for Continental use on the Bentley. Rm{William Robotham - Chief Engineer}/HJ. | ||