20-06-2018, 08:09 AM
The light spring is not fully extended at idle. However the heavy spring is loose at rest and only the light spring works initially. Once the heavy spring comes into play its effect far outweighs the light spring and controls the advance.
ie It is a 2 stage process. I think this emulates the manual system where the ignition is retarded to avoid kick back then advanced when the engine starts.
This is certainly how the Ducellier distributor works on the Citroen SM V-6 Maserati engine. The initial timing on this engine is after tdc and advances to 20 degress before tdc at 2000 engine rpm.
The pictures of the accuspark distributor show that it does not operate this way having 2 similar springs. I don't know what the original DK4 specification is.
ie It is a 2 stage process. I think this emulates the manual system where the ignition is retarded to avoid kick back then advanced when the engine starts.
This is certainly how the Ducellier distributor works on the Citroen SM V-6 Maserati engine. The initial timing on this engine is after tdc and advances to 20 degress before tdc at 2000 engine rpm.
The pictures of the accuspark distributor show that it does not operate this way having 2 similar springs. I don't know what the original DK4 specification is.
Jim