C2 Distributor Ground Wire Question

[Dave B.]

When removing the distributor cap on my '65 300hp, I noticed the ground wire from the breaker plate to the vacuum advance mounting screw was broken. Previous posts indicated lack of this ground should have caused significant driveability problems but I noticed none. Replacing the wire resulted in no change in performance. Is this actually just a parallel ground? Isn't the plate effectively grounded thru attachment of the distributor to the engine?

Dave Brown

[John H.]

Re: C2 Distributor Ground Wire Question

Isn't the plate effectively grounded thru attachment of the distributor to the engine?

Dave Brown

Dave -

The breaker plate effectively has three grounds - one through its contact with the upper bushing, one through its contact with the rod from the vacuum advance, and the discrete ground through the wire to the vacuum advance attaching screw; all of those get their ground through the attachment of the distributor housing to the intake manifold (through the hold-down clamp) and from contact between the machined areas on the housing and the walls of the hole in the block.