Gorts 5th

Hey all.
Ive been having distributer cap issues
The center button too the rotor burns up way to quick.
Why the heck is it made out of carbon?
My ignition is Mallory (rest in peace).
Electronic distributor. 42 series i belive.
Pro Classic coil..
Im wondering if i where to modify it with w brass button
Maybe a button to cover the carbon button.

RacerHog

What Cap and Rotor have you tried? Sounds like you need an MSD or Accel cap?

Gorts 5th

Its all Mallory but now Its MSD.
MALLORY s out of business.
MSD has replacements wuth the same button.
I have 4 diffrent styles of caps.
1 oem "mopar".
1 MALLORY from electronic series 43 distributer.
1 MALLORY from a uni-light. The cap was purchased in the 90s.
1 cap from a pertronix flame thrower 2
All accept the oem caps have a carbon button...but the oem appears to have an aluminum button.
The mallory cap from the 90s has a very long spring loaded button .

Gorts 5th

What about coil wire leangth.../ resistance?
Will that cause a wear like this.

RacerHog

No The leanth should not effect it that much, I mean within reason.
Look down the town on the cap and see if it, maybe it's been jumping arc?
If you see that it has, then the wire end is just not seating down in the cap deep enough, and that's whats putting the load on the carbon tip...
Also check the pre-load of the rotor to button, might be too loose. But that should be easy to see on the rotor side... (Black Marks)


Some Noise resistant plug wires will mess with the MSD. But most of the time you see miss fire tracks inside the cap.


I ran a Mallory Hi-Fire VI for quit some time with out any issues.. Wounding why you are having those issues? Humm.

Gorts 5th

The cap has hei terminals
The pre load on the rotor seams fine.
I see no sighns of arching.
Now that Mallory is out of business. No real tec department.
Im certine msd. Has a replacment cap not sure about accel. Though mallory and accel where the same.at one time.

Gorts 5th

Some pics.
Summit racing has the cap.
I left a comment on the product.
But at $45+ a pop they got to last more than a 1000 miles.

RacerHog

Are they all the 2 peace rotors?

MSD, Malloy, Accel, Holley owns all of it...

Gorts 5th

Yes as as ive been sent they are 2 piece.

I did not know that about holley.
Summit is going to replace the cap.
Still the warranty/new part is msd.
But there is still the issue that it should'nt happen so fast.

TVLynn

I have no real idea other than to make sure you have a good ground strap from the frame to the engine

RacerHog

Ok, I believe the problem is where the 2 peaces are matted together for the rotor. one of those two side has a coating? (If i recall) and you have to sand it off where it is matted with the other piece.

Or switch to a one peace rotor and see if that fixes it....

just my 2 cents....

Gorts 5th

I ill check that two piece set up for a coating....
Though i will say if thats the problem what a shame.

Gorts 5th

Ok i checked it, took it apart sanded the two matting sufaces and reassembled It .
Though i didnt see any obvious coatings will have to wait and see.
The one piece was copper, the other spung chrome steel can't imagine how the two differ in conductivity.

Gorts 5th

All right recieved the replacement cap it's gitting cheap.
Made in mexico.
I've boxed the old cap awaiting the day to return it.
Of corse i have two old caps.
....any further idea's why this button is burning up so fast???
Or how to solve it..

Gorts 5th

RacerHog

You still running the 360 Small Block..?
So this is what you are running? >>> https://www.msdperformance.com/produ...ler/parts/8388
I'm thinking you got a few mixed matched non-compatible parts?

Gorts 5th

Well the system is all Mallory.
So im a little put back by it possibly being none compatibility issue.
42series diz.
Pro Classic coil 500 ms. Duation,
i think 55k voltage...
Its wired correctly.
Im using correct wires.
Accell super stock.
Champion plugs

Gorts 5th

Tell me more?
If the ground strap is weak. Will you see a pulse in the amp meter/or lights?

RacerHog

OK... I got it... The MSD part is what threw me off.....

As I stated before...
Coil wire needs to be plugged in all the way down in the cap.
Make sure there is not an air gap between the rotor and the cap carbon.
Make sure you have good continuity threw the rotor, (Good Mating where the 2 pieces mate together)

If those are all good.... The fault is with the Carbon itself..

Just my 2 cents..
Keep us posted....

RacerHog

No so much... That's normally a the typical Mopar alternator low speed low output problem.

Bottom line... If grounds dont make it back to home base. It like a hot leaving home base and not making it to the source...

Gorts 5th

Good day all.
Thanks for the input.
Ok so far the carbon looks "alright"
I was running about 12* btdc so i got alittle spark flashing on the inside of the cap.....actually quite a bit.
I reset the timing 10* also recurvered the mechanical advance.
I guess I'll be tuning it for awhile...more.