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).
Graph comparing the performance of Lodge and KLG spark plugs at various plug gaps and engine conditions.
| Identifier | ExFiles\Box 162\2\ img002 | |
| Date | 21th June 1939 | |
| COMPARISON TESTS OF LODGE 640 SINGLE POINT AND K.L.G. FLB30X PLUGS. TESTS PERFORMED ON CHASSIS 38.IV No. 6 CYL. BEING USED THROUGHOUT. LODGE 640 S.P. CURVES SHOWN THUS. --- K.L.G. F.L.B. 30X MAX. VOLTAGE ACROSS POINTS (K.V.) PLUG GAP. PICK-UP SLOW RUNNING HIGH SPEED E.50/8 21.6.39 | ||