Distributor contacts burned?

[enkeivette]

Not sure what they're called exactly, but in my MSD HEI distributor the contacts (8 metal contacts that the tip of the rotor brushes as it spins around) seem to have burned up (they look like they've overheated).

Is this normal? What could be the cause of this? The dist is only 2 years old/ 10K miles.

I've had a weird rough acceleration that I've been chasing for awhile. I first noticed that a few of my spark plugs were arcing on the headers, then I noticed that some of the spark plug wires were open, then I noticed that I have an intake manifold leak. (In the process of installing a new intake gasket). I'm wondering if these burnt contacts could be the culprit.

[MileHighMan]

Not sure what they're called exactly, but in my MSD HEI distributor the contacts (8 metal contacts that the tip of the rotor brushes as it spins around) seem to have burned up (they look like they've overheated).

Is this normal? What could be the cause of this? The dist is only 2 years old/ 10K miles.

I've had a weird rough acceleration that I've been chasing for awhile. I first noticed that a few of my spark plugs were arcing on the headers, then I noticed that some of the spark plug wires were open, then I noticed that I have an intake manifold leak. (In the process of installing a new intake gasket). I'm wondering if these burnt contacts could be the culprit.

The wires shorting out to the headers was your accelerating problem. The burned contacts are normal IMO. I install a new MSD dist cap every year. Good Luck. Dan.

[RL]

Could it be something with the rotor button phasing, your timing may be right but the rotor button might not be exactly pointing at the cap pole at the firing point

[Warpspeed]

As you will be buying a new distributor cap anyway, right ?

Cut a large inspection hole in the top of the original distributor cap, and see exactly what is going on with the rotor button when the plug fires.

RL is correct, there may very well be a phasing problem.

[jmarkaudio]

If your wires have too much resistance or your plug gaps are too wide, you will put more load on the cap and rotor. As a example, try and run a Digital 7 with a stock HEI and you will burn the center conductor on the cap. I takes a low resistance button to fix it.

[kirkwoodken]

what warpspeed says. You can grind some holes in the cap with sanding drums, or whatever. Make sure they are big enough to see the contacts and rotor. With a timing light connected, check out where the rotor is in relation to cap contacts. It may surprise you. Get the phasing right and your engine will run better. You should be able to look at the cap and rotor and see if the contacts are burnt at one side or the other.

Buy a box of neoprene or plastic gloves from Walgreens. Wear the gloves when you work on ignition parts. You do not want to touch high voltage parts with bare hands and get finger prints on them. Finger prints contain oil and salt, neither of which should be on high voltage parts.

Oil collects dust, which will conduct high voltage.
Salt attracts water, which will conduct high voltage.