Started it up this morning, warming it up, and noticed some missfiring, so got out, popped the hood, and one of my spark plug wires was on FIRE!! I got some loose dirt and tossed it on to put the fire out, so no real damage there. BUT. It was NOT the pug I was most worried about with heat, but a totally different one. So...what can I do to keep this from ever happening again?

I have Sanderson Block Hugger shorty headers. They cost me about 200 bucks, soooo......I'd LIKE to NOT have to replace those. They are good, decent quality headers. Plus, the collecters are very high off the ground, unlike mid and full length headers, which is big for me.

I have over the valve cover spark pugs with a chevy bow tie vortec style loom.

Does header wrap really work? How hard is it to put on, because there is not a lot of room between pipes on the headers. I really am tired of trying "solutions" that don't work.

I also have short style accell spark pugs, to make a little more space between the boots and the header pipes. I don't think that actually helped much, lol.

Thoughts?

 

I would say you need to find the source of the fire first. Did the wire get too hot and catch on fire? Which plug were you originally concerned with and why? Sounds like you have taken time to prevent something like this from happening so before any parts removal takes place it would be good to narrow down what is functioning properly and what is not. Got any pics you can post up?

 

I usually warm the car up for 1-2 minutes before driving. How hot could the headers have been while "warming up" the car? I would think the fire was electrically caused, as the headers have been much hotter before when driving, without catching the plugs on fire. I don't have a suggestion. I am just talking it through.

 

...bang...!

 

I don't have pics, but I can describe it very well. I had 2 issues before. 1 was arcing from spark plug boot on cylinder 5, due to it's proximity to the header. Got that sorted out with a bit more dielecric grease, and a non fouled boot, and shorter, better quality spark plugs. Heat was always a concern on plug wire 7, because the way it has to travel to get to the dist, coming VERY close to the header. I always kept an eye on it, because I was worried engine vibration could shift the wire to the point it might touch the header. The driver side, same spot, had no issues because the wire was hed back by the dipstick.

The wire that got torched this morning is cylinder 1. Which I thought was far enough away. No way it touched. Had to have been ambient heat.

It DID take me quite a few turns of the key to get it started (it was about 45 degrees this morning). Could that cause a fire? No, right?

 

 

Sounds to me like the fire was electrical. The symptom that you noticed first was a misfire, which could have been caused by a defective plug wire grounding or something. Maybe a defective wire was arcing which caused the fire. Especially since you had just started the car and things may not have been hot enough for long enough to start a fire by heat.

Maybe longer wires needed? Sounds like you need new wires anyway...or at least one!

 

i needed a longer wire than came in my set for my 76 on cyl. #1 it hit the header and was arcing try a longer wire

 

check for wire cracks, arcing wire, little bit of gas leak from carb & you got fire. not good, go to a mechanic if you can't pin point problem. Small price to avoid disaster. Most auto shop sell a spray electric sealant. it does help to keep things from arcing but only for added protection. Need to find root of problem. Get a set of quality wires & boot and have a pro install. Then you can enjoy your ride with no worries. Also check for gas leaks, something was providing the fuel, sounds too quick to catch on fire unless you have fuel!!!

 

You have to rectify your issue of clearance of your plug boots and wires from the hot exhaust manifold.

If the boots or wires actually touch the exhaust they will fail.
Use a different boot style, or longer wire to come in at a different angle, and then ensure all the wires are held in place to eliminate possibility of touching.

I had this issue with my new crate engine....
after replacing the plug wires and boots several times, and even fitting those high temp plug boot covers, it was not reliable.

In the end I had some custom headers built to solve all the issues of plug and wire clearance, easy access to plugs for changing, better flow and excellent ground clearance.
No problems since.

 

Headers channel exhaust gas, which is HOT, even when the motor is COLD. 5 minutes is MORE than enough time for headers to be, say, 600-700 degrees. And I like to warm my car up till the water temp is about 120, or so. So the headers were PLENTY hot to start the fire.

The plug wires were MSD street fire wires. Anyone know a decent brand for under 100 bucks? I was NOT impressed with the street fires, they came with a fouled boot, had to replace it after 1 day of driving.

I'm not against making a custom set of wires, so I can alternate boot angles, so, say, cylinder 1, 2, 7. and 8 can have a straight boot, and go out and over the headers, or something....


But what's a good brand? SBC, so nothing over 8.5mm. Prefer black...

Also, has anyone ever actually used header wrap, how hard was it, and did it work?

 

I'd buy an extinguisher and keep it in the car also.

 

Done. One of those things I kept meaning to do. Did it first thing after work yesterday, lol.

 

here what i use on the big motor in my camaro and i have them on the vette also got them at orielly auto parts been using them for many years about $30

 

Wow, I dont have one of the big blowers coming out from under my hood but I do use the plug covers that you are using. My covers actually touch the headers and have changed the color to a white where they touch. So far no problem. I actually have the covers down over the boots not just the wires. I just drove the car from Pa to Ocean City for the vette show this weekend. So far I am happy with the results. No problems.

 

Your solution is only a temporary fix.
Reroute your plug wires, or use different style of boots and or use shorter plugs to get the clearance required to save your leads from premature failure.

If they are touching they WILL fail. Been there, done that!

The discolouration is already an indication that the plug wire has had molecular deterioration which will have affected its properties.
You will find that it WILL be quite brittle in that white area.
If its working at the moment, you'll find it will more than likely fail the next time you remove the boot to check the plug (s).

 

I disagree that is not a temporary fix this is the best solution for not letting your plug wires touch your headers they are the only fool proof way to make sure your $100 set of plug wires dont melt ... like i said i have been running these for many years and have not had a plug wire problem yet, my camaro runs low 8's in the quarter and is street drivin weekly weather permitting.

 

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Does header wrap really work? [/QUOTE]

good way to have a vette bbq, all the racers stopped using the wrap by my place, absorbs oil and well makes good for fires. my brother in laws modified being a victim along with others

 

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Why dont you put a real motor in that car!!! HOLY CRAP!!

 

davecour: Not refering to your car matey.
Looking at your motor, it appears you have adequate clearance of the wires from the headers, and the heat shield covers provide additional insulation for good measure.

my post was directed to Rod7515.

His plug wires are touching exhaust, and ARE discoloured.
Putting on heat shield covers in his situation will not eliminate his problem.

The heat cover will be hard up on the exhaust, and will still pass heat through to the wire inside.
Like I said... been there and done that and had to replace several expensive "heat resistant" lead sets to eventually solve the problem.

YOU NEED TO HAVE A CLEARANCE (air gap) between the plug wires and the exhaust system to provide reliable long term serviceability of your plug wires and boots.