distributor rotor, grease?

[TomInCologne]

Good Morning, FordBarner...


i was watching the rotor on my distributor through the transparent cover the other day in the dark whilst the engine was running and noticed not only the sparks on the four connections to the electrodes, but also sparks in the middle, where the rotor connects to the contact from the coil.


After opening the cover, i saw that the rotor was darkened (which may be totally fine), but also the contact within the cover was very pitted. I assume that that is not good for the contact, as evidenced by the sparks when the engine is running.


I put some graphite paste onto the rotor and that stopped the sparks.


I did not find any recommendations regarding that contact. Graphite paste? Copper paste? Nothing at all? What do you guys do?


Tom

[johnbuckley]

The carbon brush on the top of the dissy that contacts the spring of the rotor arm eventually wears down; it starts off about 2mm prominent of its brass surround. I have come across a couple of As were a misfire was due to the brush having worn right down to the brass. I have never used any lubricant on it. Maybe a new cap (and possibly new rotor arm) will solve the problem.

[Kurt in NJ]

If the carbon button doesn’t contact the rotor both will be destroyed shortly.
should never be sparks there
And no grease.

[nkaminar]

I think Tom may be on to something.

[TomInCologne]

if using electrically conductive grease, i fail to see how things could be negatively impacted. And, as i reported, the sparks on the top of the rotor disappeared.

[johnbuckley]

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Originally Posted by TomInCologne

if using electrically conductive grease, i fail to see how things could be negatively impacted......

... unless of course the grease also gets splattered (or runs) elsewhere too.

[Kurt in NJ]

if the spring tab on the rotor contacts the carbon button there is no arcing.
I am still using the rotor and cap that came with the car (50+years )
If there is a gap the rotor contact will get a hole burned in it and the carbon button will go away.
Bend up the contact spring or replace the GYP parts.
A little conductive grease splattered around the cap will create a pathway for the spark to go the wrong places and possibly burn a carbon track to ground.

[johnbuckley]

Originally Posted by Kurt in NJ

I am still using the rotor and cap that came with the car (50+years )

Gosh that's good , I reckon that the carbon wears down in 10 000miles or so . May be the originals were harder crabon?

[Synchro909]

Years ago, I had a distributor cap in which the carbon contact was worn down to the brass. We were going on a rally in a few days so I had to fix what I had (replacement parts took a couple of weeks to arrive). I took apart an old dry cell battery and saved the carbon rod down the middle of it, then drilled out the remains of the carbon in the cap. With a little fiddling, I made the carbon out of the battery fit the cap. That was about 60,000 miles ago.
Another option would be to reshape a brush out of a generator or starter motor.

[TomInCologne]

Originally Posted by johnbuckley

... unless of course the grease also gets splattered (or runs) elsewhere too.

obviously i didn't put a lot on the rotor, just a bit more than a light coating...

[katy]

Originally Posted by TomInCologne

I put some graphite paste onto the rotor and that stopped the sparks.

Is graphite paste the same as graphite grease?

[TomInCologne]

This is what i used…

it says grander grease