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).
Letter to The Lodge Sparking Plug Co regarding the performance testing of new KM4 spark plugs in an Eagle engine.
| Identifier | ExFiles\Box 79\1\ scan0116 | |
| Date | 16th July 1918 | |
| X.601 RH{R. Hollingworth}3/L016.7.18. 16th, July 1918. The Lodge Sparking Plug Co Ltd., RUGBY. Dear Sirs, For the attention of Mr. Alec. Lodge. The new KM4 plugs have run so far 20 hours satisfactorily. We are running our test 10 hours per day. When Lieut: Travers brought these plugs to the Works, we took an "Eagle" production engine and fitted it with a set of standard KM3 plugs. After 2 or 3 minutes running full power, 3 or 4 of the plugs were pre-igniting. We then took those plugs out and put in the KM4, they were quite satisfactory. We find that the low grade petrol we are being provided with for engine testing, tends to cause the plugs to pre-ignite. We think there is no doubt, if the nickel point can be held satisfactorily in the copper electrode, the KM4 plug is a distinct improvement over the KM3 because the plug is much less likely to cause pre-ignition and yet still retains its virtues as regards not oiling up. Yours faithfully, R.R. 255 A (400 T.) S.C. 536 16-2-16 G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1046. | ||