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 from AC-Sphinx Sparking Plug Co. regarding plug performance with screens and a request for engine drawings.
| Identifier | ExFiles\Box 163\5\ img056 | |
| Date | 4th September 1936 guessed | |
| THE AC-SPHINX SPARKING PLUG CO., LTD. CONTINUATION SHEET No. 2. I would have suggested that you test out these plugs without screens, but as I feel that the screening, and its consequent restriction on cooling at the top end of the insulator, may have a real effect on the plug performance, I am not advocating this course. Awaiting your reply, I am Yours faithfully, N.F. STOCKBRIDGE, Managing Director. P.S. The design (B) shown on the enclosed drawing X412A is the design of plug as already sent to you. N.F.S. P.P.S. To enable me to study all the possibilities on this question of mounting the screening extensions, will you please, when replying to this letter, let me have a sketch showing the cross section through the plug position in the engine, showing the pocket in which the plug has to fit, i.e., the space available above the plug gasket. If you can give this showing approximate dimensions, it will be helpful. N.F.S. Enclosure. | ||