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).
Comparison between Delco and Remy ignition distributors, with a discussion on carbon contacts versus jump spark systems.
| Identifier | ExFiles\Box 37\1\ scan 047 | |
| Date | 17th April 1918 | |
| Contd. -2- Oy-6-FMF-17.4.18. allowing for the advance and retard positions. X.800. X.1819. The distributor is mounted in a somewhat similar way to the Remy ignition, but the Delco is very much better in detail. For example, they do not trust to long, spindly wires screwed to a moulded paper cover for the distributor, and neither are they in agreement with the jump spark distributor, but prefer the rubbing type. The carbon contact, however, is of the type used on the Old Dixie Magnetos, namely, a round pencil about 3/16" diameter and 1/2" long. I told them I did not like the look of this form our experience with the Dixie magnetos, but they said they had taken great care in selecting the proper carbon, and also in having the right material for the distributor itself. This point is referred to later. The contact is radial - not a face contact. X3299 Asking them why they objected to jump spark distributors. Mr. Kettering, the chief engineer of the Delco Company (one of the former electrical engineers of the) (said to be, <strike>country</strike>), stated that the additional battery voltage required to push the high tension current across the jump spark distributor would be four volts, with a consequent increase of battery weight. I imagine this might lead to contact breaker trouble also. Of course, in a magneto a much higher voltage is available at the high engine speeds, and there is in any case a considerable amount of reserve energy in a magneto revealed by the purple are following the spark proper. There is very little of this in the Delco ignition about as much, I should say, as there is in the spark from the motor cycle type of Dixie magneto. Contd. | ||