The Stovebolt Site Forums The Shop Area Engine Shop The 6 Cylinder distributor

I'm not sure if this has ever been mentioned by anyone else on this site, maybe I have in the past not sure.
This I feel is not a well known issue, but I feel it could slightly affect the operation of these engines at times.
Since the whole distributor moves for vacuum advance, that means that any ground or current path to ground has to go
through a moving surface at all times. Could be the shaft bushings, shaft to oil pump or cam gear, could be at the distributor body and engine block interface
could be at the clamp to vacuum advance mount plate, etc. etc.
My advice is to use one of the small screws on the side of the distributor body that holds the breaker plate, and have a ground wire from there to the engine, like maybe one of the coil mount bolts.
This way there is a good solid ground for the points.

Look a little closer- - - -there's a spring loaded copper (or maybe brass?) ground built into the vacuum advance unit. If you choose to use an extra ground wire, make sure it's a "high flex" type like the wire used for voltmeter test leads. The constant movement will cause conventional primary wire to fatigue and break strands very quickly.
Jerry

Jerry I know about that spring loaded deal. Its still a sliding or moving connection and is probably just fine, I like redundancy. Hmm I'm just being goofy here, but why a fancy wire if you think its not necessary to have it? And yes agree you are so correct about the wire.

Sort of a "belt and suspenders" situation- - - -if you're going to go to the effort to add an extra ground, it might as well be something that will work for quite a while. Ford distributors in the 1960's and 70's used a wire from the coil to the distributor that went all the way to the points. It had a nasty habit of breaking strands between the grommet that plugged into the housing and the points inside the insulation, and cause an intermittent stutter when the advance moved. We would diagnose it by disconnecting the vacuum line, and the stutter would go away. It was a common enough failure that I got into the habit of keeping a few of those wires in stock at the shop along with the points and condensers and other ignition parts my jobber stocked on consignment.
Jerry