Thread: Burned plug wires - ideas from the gurus?

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Guys,
The old '69 Nova w/ a 468, blower, headers, & Merlin heads decided to run awful rough this spring. When checking the plugs I noticed that three of my plug wires had been seriously burned by the headers, and this was "through" the spark plug heatshield boots that I have on each plug. Tonight I changed plug wires and took it for a ride. When I got home after about 15 minutes of driving, three of the plug wires had smoke coming out of the heatshield boots. I run a coil-per-cylinder MSD ignition system, so the wires all come straight down to their respective plugs - it's not like they're wrapping around the headers all over the place. Also, timing maxes out around 34* total and all in by 2500 rpm, so I don't think I'm advanced to the stage of causing overheating. Finally, I'm running a Bill Mitchell Hardcore 870 carb with 80 jets in the front and 87s in the rear, so I should be rich enough to avoid any lean overheating issues.

What do the rest of you do to deal with heating issues like this?

As always, Thanks!

bbc with headers can burn the boots you want them away from the headers i have only seen one set s of wire boots that can take the heat if your runing the stock tin heat shields with the headers i would take them off they were never made to take the added heat from a thin wall header. they will just be super heat the shield and burn up the boots .i used the boots you can bend for bbc a set 90 boot can work .a photo would help . i think your ok on jets and timming it is just a bbc thing i use RM wire looms and takes time to do the wires so they are not in the way of the header tubes

It isn't real pretty but I use this stuff on two of the wire boots that pass too close to the headers. I can bend the other boots to give enough clearance but these two are just too close...

I used similar stuff on the merc. i think they were made for the ricers, but i used them anyway, worked real good!

Thanks everyone. I made a couple of 90-degree boots in place of the straight ones and that helped two of my three cylinders. #5 seems to want to touch regardless, and I can see where the previous owner "dimpled" the header to make room for a socket just to change the plug. I'll experiment with some heat wraps and "modify" the header as necessary I guess.

I love the BBC, but don't seem to recall some of these issues with my SBC...

What finally worked was a combination of the Accel "shorty" header plugs and the heat boots. Looks like I'm back in business, but I have a whole roll of header-wrap on hand just in case I need to make "adjustments."

Thanks again everyone...