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 suitability of various cars and engine combinations for spark plug testing.
| Identifier | ExFiles\Box 162\3\ img205 | |
| Date | 22th August 1940 | |
| - 2 - At the moment the most suitable cars for plug testing are 1-B-50, 9-B-V and 4-B-50. TO Mr. Froth from MR/RC{R. Childs} O.C. MyW/MRW Rm{William Robotham - Chief Engineer}/RC.{R. Childs} Testing Plugs. During the last few months we have had very little opportunity for sparking plug development. Firstly, both KIX and Lodge are too busy with other work on the car side. Secondly, the conditions under which our two engines are now working on the road do not provide very accurate information. At the moment the Champion "S.M" is the best plug for the 10 engines. Until recently we have tried Champion plug No. G.L.8, but now consider that the longer reach is an advantage with regard to weak mixture running. Even the KIX.WE.SOX as used on the G.III engines were turned down also with this need to be filed on 9-B-V because the engine was defined to go on fitting a short plug. Nothing had been switched off. The fitting of the Champion M.8 plug has cured this trouble. However, it should be mentioned that the same plugs - VA.SOX - are fitted to 4-B-50 and B-80 (No. 8.) and are giving no trouble. For the Bentley V engine, the Champion GL.{G. Linnett}8 is at the moment the best plug for all round conditions. The KIX.W.SOX - standard - is a close second and slightly better for town conditions. In this case the Champion GL.{G. Linnett}8 runs a shade too cool. The KIX.W.SOX is the most suitable. The Lodge C.3 have given an improved result. Lodge. We have even tried these out in W-1 without success. We would like to try these out on B.S.8 and 1-A-1 sons, for plug testing. The contribution on this car is poor, and does not justify the short trips which were taken. In case of admission to the pool, we were forced up the boot, we have tried numerous types because missing has been a real cause. To leak a plug without success. | ||