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).
Results of comparative sparking plug tests on a J.B.IV engine.
| Identifier | ExFiles\Box 162\1\ img041 | |
| Date | 22th September 1938 | |
| To R-by.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/YD. C.C. Hax. C.C. Devereux. C.C. Wynd. C.C. HA/OWN. W/A.{Mr Adams} Rm{William Robotham - Chief Engineer}/YD.B/MH.{M. Huckerby}22.9.38. SPARKING PLUG TESTS ON J.B.IV. We have completed tests on J.B.IV to show the voltages across the sparking plug points under various conditions of running, i.e. slow running, pick up and high speeds with plug gaps varying from .020" to .040". Four types of plugs were tried Champion L.S.8, KLG.FLR.30x, Lodge Sintox Singlepoint, and Lodge Sintox three point. One plug of each type was tried alternately in the same cylinder. The Champion L.S.8 was the most efficient, requiring considerably less voltage under all conditions. We have fitted three new Champion L.S.8 and three new KLG.FLR.30x (standard) in alternate cylinders of J.B.IV to check up on wear and performance. The attached figures show the comparative merits of the plugs tested. Rm{William Robotham - Chief Engineer}/W.Brazier. Rm{William Robotham - Chief Engineer}/F.Dodd. [STAMP: SEP 28 1938] | ||