Plug Wire Burning on Headers

[JonCheun]

I've been trying to get my 1968 C10 to pass smog. In Nevada it's 1967 or older don't require smog. Some say to get classic plates but that limits you to only driving 5000 miles a year. Some say to just disconnect the odometer cable.

It passed fine last year so I don't know why it wouldn't today.

It's failing on the Hydrocarbons.
I found out that the plug wires on cylinder 5 and 6 are burning up on my headmann headers causing misfire which explains the high hc levels. These are the 2 pair of plug wires I have put on them. I even put heat shields over them this time and the headers still burnt through them.

I'm going to replace the 2 wires that burnt up but was wondering if there is any heavy duty heat shields that can help. If not, I will have to reroute them so that stay away from the headers.

[egaray281]

http://www.oreillyauto.com/site/c/de...6+wire+shields

try these i have them on my truck and i also have headers this was the only way i stopped burning my wires!

[MusicMan70]

Yep I use those as well; gotem from EBay

http://www.ebay.com/itm/370784237343...84.m1423.l2649

[cdowns]

i too believe in those plug boots

all sparkplug wires are not created equal// i never had a heat problem with top of the line taylors

[special-K]

How are they routed? I have no problems with burnt plug wires from headers and I run them up and away from the headers. No heat shields ever. I also prefer Taylor. They are the best

[JonCheun]

Originally Posted by special-K

How are they routed? I have no problems with burnt plug wires from headers and I run them up and away from the headers. No heat shields ever. I also prefer Taylor. They are the best

They run from the distributor along side of the valve covers and down in between the header pipes. The issue is only on 5 and 6. those were the hardest spark plugs to change. I actually had to get those from underneath with a open end wrench. The Heddman Headers were existing so I didn't mess with them.

[JonCheun]

Originally Posted by egaray281

http://www.oreillyauto.com/site/c/de...6+wire+shields

try these i have them on my truck and i also have headers this was the only way i stopped burning my wires!

Those were what I bought for 5 and 6. It burnt right threw them.

Before I changed these plugs and wires. number 6 had a heat shield on it. It was like a foil tape almost. It was old so I threw it out.

[JonCheun]

Originally Posted by egaray281

http://www.oreillyauto.com/site/c/de...6+wire+shields

try these i have them on my truck and i also have headers this was the only way i stopped burning my wires!

Those were what I bought for 5 and 6. It burnt right threw them.

[egaray281]

Originally Posted by joncheun

those were what i bought for 5 and 6. It burnt right threw them.

yea i have them on 5 and 6 i check every few days and well so far so good for me? Also let me add that my truck isnt a daily driver so maybe thats why i haven't burnt threw them yet?

[steelhorse]

They make shorty plugs to give you a little more clearance for this reason. Maybe those would help.

[GASoline71]

I have Headman Hedders on the 350 in my rig, with MSD wires and 90 degree boots. Never burned a single wire, and the MSD boots are pretty bulky.

You're not trying to use straight boots designed for manifolds are you?

Gary

[JonCheun]

Originally Posted by egaray281

yea i have them on 5 and 6 i check every few days and well so far so good for me? Also let me add that my truck isnt a daily driver so maybe thats why i haven't burnt threw them yet?

The Heat shields are only two weeks old.

[JonCheun]

Originally Posted by GASoline71

I have Headman Hedders on the 350 in my rig, with MSD wires and 90 degree boots. Never burned a single wire, and the MSD boots are pretty bulky.

You're not trying to use straight boots designed for manifolds are you?

Gary

I'm not trying to use straight boots at all. I'm using MSD wires with 90 degree boots.

[Lee H]

How close is the boot to the header?
Posted via Mobile Device

[JonCheun]

Originally Posted by Lee H

How close is the boot to the header?
Posted via Mobile Device

It like 1" 1.5" but the boot isn't the issue. It's the wire a few inches before the boot.

[67swb72klb]

I like routing them down and under the headers

[Lee H]

MSD wires burning up several inches from the tube? That thing is getting way to hot.
Posted via Mobile Device

[magwakeenercew2jh]

Originally Posted by Lee H

MSD wires burning up several inches from the tube? That thing is getting way to hot.
Posted via Mobile Device

Yeah. I was going to suggest what I'm running. You can adjust the "play in the wires and clamp them down wherever you want.

But if they are not touching, and burn through when the wire is two inches away from the header???? Something else is rotten in Denmark.
If your timing was too advanced, or you were running waaaay lean, I'd suspect you'd have already had a bigger problem...

.....But what do I know?

[GASoline71]

You need some sort of wire loom that will allow you to bend the wires around the tubes and hold them in place. The cheap wire looms that come in the kits isn't enough.

So it's not the headers or the plug boots... it the looms that are causing the problem.

I am using some cheapies that I got from Summit. They bring all the wires together, and then run them to each plug. They work pretty decent for the price. But there are cleaner, and albeit, better options out there.



Gary

[jhwkns]

Originally Posted by cdowns

... I never had a heat problem with top of the line taylors

^^ What cliff said

[BlackedOut67shorty]

Mine are also ran under the headers with accel 300 plus. Didnt burn them after about a thousand miles but I think your header is getting way too hot if its burning through the shields
Posted via Mobile Device

[JonCheun]

I don't know why these photos show up side ways.

I use wire looms that bolt to the valve covers.

The heat shield actually has some contact with the headers.
The heat shield doesn't look or feel burnt but when I remove it the wire is burnt.
I don't think my headers are getting too hot. The Engine temp is still 185-195 F.
I'm just going to have to route 5 and 6 under the headers.

[Lee H]

I see, those are the same looms I use. You have them routed to close to the exhaust. Try to pull more wire through so they almost touch each other as they curl down and then toward the plug, see picture. With the way that top tube runs, looks like you are going to have a continuing problem. My 5 wire is 1 1/4 inch from the tube and has never burnt.

[Lee H]

You can also bend a tighter radius in the bracket to get the wires closer to the block. I did that.

[JonCheun]

Originally Posted by Lee H

You can also bend a tighter radius in the bracket to get the wires closer to the block. I did that.

How did you bend a tighter radius in it?

flat corner and a rubber mallet?