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 A.C.-Sphinx Sparking Plug Co. Ltd. regarding minimum sparking plug dimensions.
| Identifier | ExFiles\Box 163\5\ img085 | |
| Date | 4th December 1936 | |
| 6011 Experimental Department Rm{William Robotham - Chief Engineer}/Wst.14/AP. 4th December 1936. The A,C.-Sphinx Sparking Plug Co.Ltd., Dunstable, BEDS. For the attention of Mr.Corbin. Dear Sirs, In response to your telephone request we have ascertained the minimum distance we can allow you to go to on your sparking plugs. This distance is .900" from the bottom face of the plug to the top of the hexagon. On our standard Bentley plugs this dimension is 1.000", but we find it is possible to reduce this by .100" without seriously fouling the cylinder head. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||