I have a 95 Cobra with MAC replacement aftermarket headers. My issue is that the #3 and #4 plug wires keep getting burnt by the headers. How can I solve this issue w/o replacing the headers? I tried putting header wrap on the header tubes at those points as well as plug boot protectors on those plug boots. STILL, #3 went bad and got burnt. #4 seems to be fine still. It only takes like a month for them to go bad. I can't keep replacing my plug wires every month or so. Or my wife will replace ME! LOL

Any ideas? I tried 90* angle boots, but still no good.

I thought about the ceramic boot plug wires from Jacobs Electronics, but they are like $200...so thats not an option.

Then I thought about replacing the headers...but thats like $150, so THATS not an option....Any other ideas?

I thought about denting in the header tube on #3 tube a little to put some kind of air gap between the boot and the header. (right now, there isn't any gap no matter which plug wires I use) This is still the most likely course of action/cure. How much of a difference will I notice if any?

 

Just throwing it out there but....Have you ever checked to see if you have a lean condition on those 2 cylinders? Kinda odd not burning any others.

 

He's burning plug wires,.. not valves.

Have you tried different routing of the wires with plug looms so they rest in the middle? Or still too tight?

If still too tight then I think it wont matter what plug wires you use. I would try to figure a way to fab up a tubular metal cylinder heat shield and use spacers to keep the plug wire centered in the cylinder. That should prevent any more burnt wires. I had this problem when I put long tubes on the 305 in my 84 Z28. I used extra wire looms to stabilize my wires so they wouldnt bounce on the header pipes.

Hurst

 

Tommy, Hurst is right. My plugs and valves are fine....It's just the wire boots.


Hurst,
The boots themselves are hitting the header tube, so making a heat shield wouldn't really work as the heat would simply transfer through the heat shield to the plug wire anyway as it would all be in direct contact with the header.

The wire bodies are not touching the headers, but I've got them routed pretty good and away from the header. It's just the boots.

I think that heating up and denting the header in is the only cure here.

 

what wires do you have on there? I had macs with FRPp 45 degree boots and never burned in the years they were on.

 

In never mentioned the valves. Valves are made of different material than wires. Going turbo (hurst)you may wanna brush up on stuff like this. Maybe you have special headers. Those cylinders can be leaner than the rest LONG before valve damage will occur. I know nothing...carry on

 

shorter plugs? they do make them

 

they also make the plug wire wrap as you mentioned but some places sell them in pairs also. check one of the turbo forums

 

Advanced sells them in pairs

 

I had the same problem with my 94 saleen, so what I did is got a set of msd 8.5 mm wires specifically for a fox body mustang because they are longer and the the boots are longer as well, and I just angle bent the boot and then used those wire holder things ( can t remember the name ) and rerouted them and everything worked out perfect. No more burnt wires. I also have bassani ceramic coated shortys on there too so they have a funky shape to them. That was a pain in the ass. Goodluck man