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 and testing of the K.L.G. FLB.50.X type spark plug.
| Identifier | ExFiles\Box 162\1\ img035 | |
| Date | 23th January 1939 | |
| To By _to Major Carrington - K.L.G. Ltd._ _c. to Mr._ _c. to Mr/C wel._ _c. to Mr/??n_ c. to RM{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux} W/K re K.L.G. FLB.50.X. Type Sparking Plug. This type of plug, which is similar in external dimensions to the standard FLB.30.X. type but has a higher heat resistance, was submitted to us by the makers as a cure for the excessive electrode wear experienced on the Bentley car. One set of the plugs was fitted to Mr.G.H. Withey's Bentley (B.190.KT) and completed 3,106 miles without any trouble - the greater part of this being done in Germany. At the end of this period Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux} examined the plugs and reported no misfiring and no apparent electrode wear. These plugs were then replaced in the same car for further running under English conditions. After completing a total of 7,070 miles, misfires occurred when accelerating. Examination proved the plug to be running too cool. (see print B). Two further sets of this type of plug were sent to Cr.{Mr Cra???ster / Mr Chichester} (Paris) who reported after 8,900 miles running on a trial car (B.35.KU), that no improvement in respect to electrode wear was to be found. These plugs have been returned for our examination. We find that the button of the insulator on these plugs is running at the right temperature, (see Print A) and is suitable for continental conditions; but that the earth electrode is still running too hot. Up to the moment, the Champion L86 is the best all round plug for the Bentley, but is a shade too cool for the Wraith. If the earth electrode of the FLB.50.X. type were made to run cooler, it would be a good plug for continental use on the Bentley, but is definitely not suitable for cars likely to be used for running about town. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||