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 20/25 HP coil ignition, advising that spark plug gaps should be checked (.020) and plugs kept clean, rather than replacing the coil.
| Identifier | ExFiles\Box 54\5\ Scan341 | |
| Date | 15th December 1930 | |
| X5680 H.{Arthur M. Hanbury - Head Complaints} (struck through) c. EFC. c. Hs{Lord Ernest Hives - Chair}/Bm (struck through) BY/11/G.15.12.30. RECEIVED DEC 1930 X699 20/25 HP. COIL IGNITION. It is evident to us now that the present coil is working more near its limit, when it is expected to pass a spark at low temperature and high compression on the 20 HP. engine. Under these circumstances we know there is a liability of missing, and therefore it is important that Depots should be informed that the right way to deal with this is not to change coils but to check the gap on the sparking plug to make certain that this is correct to the latest instructions i.e. .020, also that plugs must be kept clean. You will appreciate the importance of this matter, and I trust that you will arrange to get it passed along without delay to the various Depots. We have already one coil back off a 20/25 HP. There is nothing the matter with the coil, (confirmed by both EFC. and Mr. Brock) and therefore the new coil which has been put on this chassis can be no better than the present one. The improvement must undoubtedly have been due to checking the plug points and cleaning. BY.{R.W. Bailey - Chief Engineer} Bm | ||