Distributor: Description and Operation

Distributor Components:

The Distributor, mounted on the front of the cylinder head, is an electrical distribution device. It provides high voltage current to the spark plugs, by directing current to each terminal of the distributor cap as the rotor turns. From the distributor cap terminals, an ignition wire directs the current to each spark plug.

The magnetic pickup unit is located inside on the stator plate. The governor base and signal generator is located on the driven shaft.

Mounted on the side of the upper body of the housing is a vacuum advance control unit. This unit is connected to the stator plate and when operating, rotates the stator plate, causing the igniter to move. This advances or retards the ignition timing as required.


Located on the governor base and signal rotor assembly is the centrifugal advance assembly. It consists of 2 governor weights held in place by springs and connected to the governor base. The weights move according to engine RPM. As RPM increases, the weights overcome spring tension and move out towards the edge of the distributor housing. When this happens, the rotor (mounted on the governor base) rotates ahead of the main shaft and advances ignition timing.