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).
Experiments and observations of ignition system components, including coils, distributors, sparking points, and governor characteristics.
| Identifier | ExFiles\Box 54\5\ Scan183 | |
| Date | 2nd February 1922 | |
| Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 1/T1. 2.22. Slight differences in the operation of coils in bakelite and in stabalite cases have been suspected, but careful experiments in interchanging coils and cases have shewn these differences to be negligibly small, so that electrically there appears no practical reason why the bakelite cases should not be as entirely satisfactory as the stabalite. Distributor. The timing of the distributor has been verified on two experimental sets as being correct. With regard to the fit of the distributor moulding, the bakelite appears to progressively shrink slightly, requiring an occasional easing out, otherwise it becomes too difficult to satisfactorily remove and replace the cover. Perhaps it might be desirable to give a little allowance here. Material of Sparking Points. Up to the present, we have only had nickel sparking points on the experimental sets, but it is understood that a number of sets of tungsten points have been instructed and a comparison between these will be best effected under actual running conditions. Ventilation of Distributor. The suitability of the ventilation provided will be confirmed as soon as one of the new type ignition sets is received. Governor Characteristic. The governor as designed cannot produce the type of advance curve needed by the engine with any kind of single spring with any amount of set. For this to be the case, a spring would be required of variable rating, which no single spring has. We are, however, experimentally modifying the design of the governor with a view to securing the desired advance characteristic and a considerable amount of success has been achieved in this direction. ø or as near as possible EFC. {E. Fowler Clarke - Electrical Engineer} | ||