[68fbird455]

Hey guys - Happy Pontiacing....

I'm in a quandry- My Mallory unililte dist cap is melted on the inside @ the center in the top - It's where the Rotor meets the cap. -I've got the complete set up unilite w/ vacuum (which is shut off) - 6al box and hyfire coil.

I've prob got maybe 7k-10k miles on it. Three different engines. A pair of 455's and 400. THis one makes the 4th and the last #'s mathcing 400.

The only thing I did different on the last 455 was shut off the vacuum.

Anyone had this problem - know why or have a solution/suggestion?

Thanks all....JOhn

[66bonne]

John - the only thing I can add is that two of my friends had the Unilite distributor in their Ponchos. The rotor contact button exploded in both of them. My friends now run GM HEIs.

Jim

[david400]

I have run one for 20 years ,Never had that problem, They do require a voltage drop 7-9 volts.

[quick67bird]

I have ran one in my car since I bought it in 1988 and have not had a problem. I have burned a module up in my Comp 9000, but that was my fault. I do run a resistor to be sure I don't have any voltage spikes.

Robert

[chuckies76ta]

I have a friend with one, that wanted to sell it. Not sure if he still has it.. Let me know.

Charles

[71 Ventura II]

With the Mallory "Unilite" module you must use the resistor to lower the 12v down to 6-7v. Also, it's highly recommended to plug in-line their Active Power Filter to eliminate voltage spikes. Back in the 80's Mallory had a bad rep surrounding the "Unilite" module failing necessitating the power filter to protect the module.

I have not seen one of the caps melt in the middle however. Strange, I'd check all the voltage readings and ground connections. Good luck! JD

[Schurkey]

If the cap melted where the coil wire fires through to the center of the rotor--I'd be looking for corrosion of the coil wire socket and the metal end of the coil wire, a bent rotor contact that isn't making proper "connection" to the coil wire button in the cap, high-resistance plug wires, and/or TOO HUGE spark plug gaps. (in approximately that order)

Since the cap 'n' rotor are probably both burned up, check the other stuff and then replace the cap 'n' rotor.

["QUICK-SILVER"]

Does the metal strip on the rotor button spring up to touch the cap, OR is the button in the cap spring loaded?

I've seen several caps melted in the middle that had spring loaded buttons. Spring would be broken making the spark have to jump from the coil wire socket to the carbon contact button. The spark arcing melted the cap.

The same would be true if the rotor buttons strip, that sprung up to touch the cap, didn't reach.

Do some measuring and see if you have an air gap between the contacts on rotor button and cap.

Also, check resistance on the coil wire. If the core of the coil wire is broken/burnt up on the cap end, arcing there might melt the cap.

Definitely something to look at/worth checking.

[68fbird455]

Hey guys - Thanks for the comments - I 've got the resistor to lower the voltage. When I installed the unit I installed the complete setup. So I think we are ok there. I also checked the gap on my old plugs - Checked ok. All my wires looked and are great.

It's got to be the gap between the button and rotor was to great because of a faulty spring on the top side of the button. Shurkey and Quick-Silver, You guys are right on. It looks like the "arc" would cause this. It was like burnt right around where the button meets the rotor. The button is gone - It's sorta burnt up too.

The kicker - that 455 was running great when I yanked it. Go figure, hungh? I think I'll just throw on another cap and rotor. Looking at it I'm pretty sure that is what it was. whew - thanks guys I feel better now.