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 history and testing of K.L.G. spark plugs over various mileages.
| Identifier | ExFiles\Box 142\3\ scan0216 | |
| Date | 1st June 1937 | |
| 1204 Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} June, 1937. 6.B.IV. K.L.G. Sparking Plugs. E.27. Herewith history of these plugs during last 15,000 miles' testin France as requested by Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} No.4. Written off by broken exhaust valve after 4632 miles. Gave no trouble up to the time. No.6. Failed after 7823 miles. Insulator cracked away round central electrode. Returned to Works for examination. Nos.1, 2, 3 & 5. Gaps re-set .028" to .020" after 7823 miles. Misfires on pick-up and difficult starting hot reported after total plug mileage of 12000. Plugs removed and returned to Works for inspection having covered 4571 miles since re-setting, and 12,394 miles altogether. Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} In 1936. 6.B.IV ran 17,756 miles on KLG 850/4 re-set (amount not given) after 5720 miles, and probably again later when engine was decarbonised, but not certain. Plugs cleaned up and put into service again after 15,000 miles' test, so presumably in good condition. | ||