I am new to the forum and I joined specifically to find the answer to my problem. I have a kit car, an Austin Healey Sebring MX that has an L98 with an Edelbrock 650 Performer carb on it, hence the reason I am here.
I searched the forum a while and could not really find any answers to the problem I am having. I apologize if it is out there and I just missed it.
Now on to the problem. I don't know much about the engine as I am not the one who built the car. The car was put together back in 1990. From what I can tell, the motor is out of an '87 Corvette. As stated, it is carbed and has some snug headers on it, which are wrapped. It sounds like it has a cam as well. This all started when I had some issues with spark arcing from the plug wires. The PO put the distributer end on the plug side and they could not handle the heat and two of them, #3 and #6 burnt the boots and were arching. It also has the heat sleeves for the plug wires. It was at this point I realized he had put on some solid core Taylor wires. Everything I have read said not to use solid core with the HEI, so I put some 8mm spiral core Jegs brand wires on. While at it I replaced the cap, rotor and coil. Did another night time test to look for arching and see that the #3 wire is doing something really strange. At first I just thought it was arching but it looks like I can actually see the spark running through the length of the wire, all the way from the distributer to the plug, from inside! Holding the wire, while it is running I can feel a small spark when I put my fingers against the metal, not so bad to make me pull away. I also can see a glow coming from down in the header wrap as well, only there by the #3, #5 area. I can only assume these two are related, but what the heck is going on with the spark?
I am pretty sure it is unrelated but, I have a slight exhaust leak over by #8 that I need to fix as well.
I checked the timing and it is at 6 deg BTDC. The car seems to run strong and pulls really hard. I had put in plugs less than a thousand miles ago and checked compression while I was there. I don't recall now what the compression was, but it was high and good across all 8 cylinders. I just checked the #3 plug yesterday and it still looks good. I gapped them at .045, which is what the ones I took out were gapped at.
Hopefully someone can explain the weird sparking running down the wire and the glowing header pipe.
Thanks!

George Rust
Cedar Park, TX

 

I've never seen it myself but I think what you're seeing is corona discharge.

http://en.wikipedia.org/wiki/Corona_discharge

 

It sounds like you have one defective wire.

 

Glowing header= late timing

 

Actually, in the dark, I've seen headers or tubular manifolds glow with timing right on.

 

Thanks for the input guys! I will add that the glowing tube was there before I changed the wires. Maybe I am wrong to think that the two are related. Since I posted earlier, I went out and advanced the timing to 10*BTDC. I took it for a quick drive and hit full throttle a couple times. Pulls hard, no detonation, and I think maybe even revved a little quicker/higher. I will check tonight to see if the glow is still there. The wrap on the header has ripped and started to come unraveled so I may just take it off of them.

 

Btw, if you want a set of plug wires that stand up extremely well to the heat of headers, and last a long, long time, you can't go wrong with a set of Moroso Blue Max wires. They're 8mm spiral core wires. I've had the same set on my 69 Camaro for probably 15-20 years now, and haven't had a single misfire or burnt wire yet! They're about 75-80 bucks for a set, but well worth the money! I went cheaper on my 89 and got a set of Megafire brand wires from Skip White on Ebay, and those haven't had any problems from header heat either. I don't think Skip carries them anymore though.