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).
List and analysis of various spark plugs for the F. engine, considering weight, length, and fitment.
| Identifier | ExFiles\Box 35\3\ scan 195 | |
| Date | 1st February 1928 guessed | |
| contd :- -2- Plug. Weight Length. ozs. drms. Lodge A.30 5 6 2.8 Champion R.11 3 2 2.2 Champion R.12 3 12 2.7 K.L.G. 541 2 7 1.6 K.L.G. 543 5 1 2.9 K.L.G. 508 4 8 3.0 K.L.G. 464 5 10 3.2 K.L.G. 356 5 0 2.9 From this short list it will be seen the great variation and all these mentioned have been possibles for adoption for the F.{Mr Friese} engine. Another point, with the long plug body (take the KLG.464 for example) it would stick out 3.2" which means that the cowling would have to have say another .5 to .75" clearance from the plug [strikethrough]tex[/strikethrough] terminal to prevent shorting, this would make say 3.7" from the cyls. to the outside of the cowling - it also means that there is 3.7" of exhaust pipe buried inside the cowling uncooled and necessitating increased engine bay ventilation. From the list the KLG.541 appears to be the type of plug to be encouraged if it could be developed into a reliable plug, as the weight and length is very favourable. We have not as yet had sufficient of these plugs to form a definite opinion as to their merits. HS{Lord Ernest Hives - Chair}/TAG. | ||