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).
Technical memorandum discussing the Delco-Remy vacuum-operated automatic advance ignition system.
| Identifier | ExFiles\Box 163\7\ img166 | |
| Date | 5th October 1931 | |
| X6036 B. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Wst. c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Ry. Hs{Lord Ernest Hives - Chair}/Wst.4/AHS.5.10.31. X4354 X7685 DELCO-REMY VACUUM OPERATED AUTOMATIC ADVANCE. The Delco-Remy Co. have produced a new system of effecting automatic advance by means of induction pipe depression. This, they claim, is fundamentally superior in regard to its adaptability to engine requirements than a plain centrifugally operated mechanism. The distributor tower is connected by means of suitable linkage to a suction operated diaphragm connected with a pipe to the induction manifold immediately against the throttle stop. The ignition distributor is thus advanced and retarded relative to the pressure conditions obtaining in the engine induction system. It has for a long time been known that a certain maximum ignition advance can be given to an engine dependent upon the conditions of load imposed, and if provision can be made to accomodate these fluctuations, improved acceleration and greater smoothness of running combined with reduced petrol consumption, should be obtained. For instance, upon accelerating, the ignition would be quickly retarded and then advanced automatically to its permissible maximum as the induction pipe depression increased. The characteristic curve of a spring loaded centrifugal mechanism does not conform to the curve of engine requirements and the Delco Remy Co. claim that their device more nearly approximates engine requirements. This suction operated automatic advance combined with an automatic speed governor would give greater smoothness of running and should obviate the necessity for any hand control at all. At the same time when the load conditions are small a maximum advance is obtained thus saving slightly in petrol consumption. The Delco Remy Co. are very confident in the success of their device and are willing to supply us with a suitable suction operated advance to suit our engine in order that we may investigate their claims, if we so desire. The new Chrysler Plymouth and Studebaker have now standardised this advance and their representative stated that several British motor manufacturers were testing it. HS{Lord Ernest Hives - Chair}/Wst. | ||