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).
Modifications to ignition timing and components to resolve a production issue.
| Identifier | ExFiles\Box 65\1\ scan0158 | |
| Date | 14th May 1926 guessed | |
| contd :- -2- We suggest that to overcome the production trouble, the ignition advance is cut off at 20° angular movement of lever E.72518. This can most easily be accomplished by lengthening cap E.72495 by .100. The ignition advance will still be adequate for all conditions, the extra advance was only given as a precaution against drop in efficiency of the unit when the heavy magneto sleeve loading and conse-quently double return springs were necessary. We suggest that none of the E.72495 at present made need by scrapped as when the alterations called for in R1/M4.5.26 are adopted, these pieces will again be required. It will be noted that R.{Sir Henry Royce} wishes to retard the actual timing of the ignitions by 8° so that every available portion of automatic advance will then be required. We are running the next 10,000 miles car with the relay chamber floor lowered .100" (E.74837) and cross head E.74836 so that by lengthening rod E.72649 .100", we shall be able to revert to the full travel of the relay with cap E.72495 as at present and obviate the present trouble of the lever fouling piston E.72509. Hs{Lord Ernest Hives - Chair}/Fm. | ||