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).
Instructions for setting the magneto ignition timing and its associated control linkages.
| Identifier | ExFiles\Box 65\1\ scan0068 | |
| Date | 28th January 1925 guessed | |
| contd :- -2- The correct timing for the magneto is 12° B.T.C. with the hand control lever in the fully retard position. One tooth on the serrated coupling alters the timing by 6° on the flywheel. It may therefore be impossible to set the magneto nearer than 15° B.T.C., or 9° B.T.C. In this case the more advanced setting should be chosen, otherwise it will be impossible to obtain the full range of automatic advance. This difficulty is obviated on cars with a taper instead of serrated adjustment. This setting should be carried out with Rod E.72614 still disconnected. The magneto being set as near 12° B.T.C. as possible with the sleeve up against the retard stop, the hand control should be moved to the top of the quadrant and the lever E.72614 coupled up and adjusted in length until the magneto points just break 20° B.T.C. In the extreme case of the magneto having to be timed 15° in the fully retard position, it may be found that in order to prevent lever E.72578 pivoting about the end of the Rod E.72587 when the flick start is being used, the Rod E.72614 will have to be lengthened slightly, making the final timing of the magneto with the hand control in the fully advanced position 21° or 22° B.T.C. Having thus set the ignitions for the hand quadrant it remains to ascertain that the controls allow the full 27° automatic advance from the oil relay. This can be accomplished by pushing the end of lever E.72518 towards the crankcase until it comes up against some definite stop. The engine should now be turned over with the hand control in the fully advanced position and the distributor points should break contd :- | ||