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).
Ignition timing settings for the high compression 20-25 HP car.
| Identifier | ExFiles\Box 5a\5\ 05-page111 | |
| Date | 16th April 1930 | |
| X 5771. To E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/AJL. c. to BY.{R.W. Bailey - Chief Engineer} c. to MK.{R. E. B. Meade-King} Hs{Lord Ernest Hives - Chair}/AJL.1/WJ.16.4.30. Handwritten notes: X5480, X5639, X5771 IGNITION TIMING ON HIGH COMPRESSION 20-25 HP. CAR. In Hs{Lord Ernest Hives - Chair}/AJL.2/WJ.6.2.30 we gave the necessary ignition setting and range required for the high compression 20-25 HP. car. This is now on production and no steps have as yet been taken to alter the controls to suit the necessary ignition timings. The alterations asked for were as follows :- Battery Ignition. (1) Range of advance on hand quadrant reduced from 47° to 23°. (2) Full advance timing (on quadrant) 13° B.T.D.C. instead of 30° B.T.D.C. (3) Flywheel markings altered to suit the new ignition settings. Magneto Ignition. (1) Full retard timing 5° P.T.D.C. (The full hand controlled range of 35° to remain). (2) Flywheel markings altered to suit. For cars which have already been made and on which it will not be possible to alter the battery ignition range, the above timings must still be used. (The retard position of the battery ignition will be very late, [17°] but the engine will run with this setting). Hs{Lord Ernest Hives - Chair}/AJL. | ||