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Because of the long tube headers on my NOM 454 68 convert, the only spark plug wires that do not get fried are the ceramic insulated ones from Accel. But.....despite lubricating them with high temperature silicone grease and careful pulling, I pulled the metal contact out of the ceramic end...... AGAIN. I have had four of these do the same thing. You can buy single replacement ones for $18 each, plus shipping. Has anyone found a way to repair the plug end of the wire, like you can do with traditional silicone rubber insulated wires?
even with the shorty plugs the traditional rubber insulation only lasts a few weeks before it is destroyed by the heat, even with those fiberglass insulating sleeves.
That's strange. I have a small block with hooker header side pipes, angle plug heads, use shorty plugs, 90 degree boots and have a Moroso wire set for years.
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
I have had one do this years back but that is the only time I had an issue with them.
like you I kept burning wires until I installed these,
I did replace the one that came apart with a single but don't remember where I ordered the single wire from, I'll look around and see if I can locate the information
MelWff - I have a NOM 454 with aluminum heads. There is a lot less room than on a small block. Plugs for cylinders #1 and #5 almost touch the headers with the spark plug wire boot on.
The metal part of the connector inside the hard white ceramic insulator is pulled out. There is no way to remove insulation and re-crimp inside the ceramic end. The other end that fastens to the distributor can be fixed easily.
Try the Jegs brand ceramic boot wires. They might work out better for you. I like the snap on terminals better than the Accell terminals. Only a few bucks more.
I've seen a lot of these burned wire threads over the years and some people have a lot of problems and others not as much. Certainly ceramic coating on the headers makes a huge difference in the heat those headers put off. But I wonder if the tune has some effect as well.
I know if the timing is run relatively retarded (near or at stock timing) that the primaries will even glow red hot they get so much heat. Maybe if it's right on the edge running more advanced timing might lower the header temps and cure the problem.
stingr69- I checked the construction of the ceramic boot for the Accel and Jegs. They both use a stainless steel contact inside the ceramic boot. This is what breaks. The contact grips the spark plug metal end so tightly that when I pull off the boot to check the plugs, the connector breaks, leaving the stainless steel contact on the spark plug. There is no way to push the wire thru the ceramic end to repair the end, like you can do with the conventional rubber boots. I have had four of these break over the last couple years. They don't get cooked by header heat, but are difficult to get off without breaking. Yes, I use lots of silicone electric grease when I install the boot on the plugs. They still grip and are difficult to pull off.
stingr69- I checked the construction of the ceramic boot for the Accel and Jegs. They both use a stainless steel contact inside the ceramic boot. This is what breaks. The contact grips the spark plug metal end so tightly that when I pull off the boot to check the plugs, the connector breaks, leaving the stainless steel contact on the spark plug. There is no way to push the wire thru the ceramic end to repair the end, like you can do with the conventional rubber boots. I have had four of these break over the last couple years. They don't get cooked by header heat, but are difficult to get off without breaking. Yes, I use lots of silicone electric grease when I install the boot on the plugs. They still grip and are difficult to pull off.
I have a set of Jeg's on one of my small blocks (90 degree boots) and never had one of those come apart. Might be worth trying a different brand?
Are the headers ceramic coated?
What is your timing set at? Excessively retarded or advanced timing can cause EGT's to go through the roof and ruin any plug wire out there......
Are the headers ceramic coated?
What is your timing set at? Excessively retarded or advanced timing can cause EGT's to go through the roof and ruin any plug wire out there......
chevymans 77.....Jegs and Summit Racing both have single wire units for sale. I just ordered two from Summit to fix a broken one on the car and to keep the other one for future use, if needed.
For people commenting on this problem. this is the clearance.....or lack of clearance.....on cylinder #1 on my 454 with aluminum heads. Rubber insulating boots touch the headers on cylinder #1, #3 and #6 and get cooked and become brittle in about two weeks. The ceramic insulating boots do not get destroyed by the heat. But....the metal part inside the boot that grips the tip of the spark plug sometimes grips so tight that it breaks when pulling the boot off, despite pulling carefully. I have had four of them break in the last two to three years.
Accel ceramic spark plug wires
