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).
Engine misfiring, pre-ignition issues, and the adoption of new 'Mercury' ignition plugs.
| Identifier | ExFiles\Box 25\3\ Scan063 | |
| Date | 1st February 1921 | |
| contd. -2- R6/CE1.2.21. changing the pistons. Regarding the misfiring mentioned by Collins, this of course we ought to avoid, being unpleasant and unnecessary. You will be pleased to hear that we have some very inexpensive ignition plugs which keep themselves cleaner than the present Lodge type. These have the wall of insulation which gets hot, like the old Pognon. You will remember that I desired this type of plug, as soon as the post-war cars shewed ignition defects. I am not sure, however, that Collins' description did not refer to pre-ignitions, if so, these pre-ignitions probably arise from the battery ignition (mutual induction) which HS.{Lord Ernest Hives - Chair} has told us is not entirely absent in the non-trembler type of ignition. It has not, however, occurred in the cars I have driven, since the coil has been moved close to the distributor. It has also been the practice lately for high tension ignition wires to be supported in an earthed metal tube. Though I do not agree with this practice, I have accepted the Experimentl Dept's views that it is necessary. The reason I do not like it is that it may detract slightly from the slow running efficiency. R.{Sir Henry Royce} P.S. I am very keen on the adoption of the new plugs mentioned above "Mercury", is the trade name, manufactured in Birmingham. Price about 1/3 each, can be cleaned and repaired by any intelligent person. R.{Sir Henry Royce} S008-G (12-2-21 "525 R S) (L DS) W/C R/H | ||