Greetings, new member here. I just got my car back from having upgrades done. Unfortunately on the drive home my C3 started backfiring. I checked things over and discovered that two of the spark plug wires going to the two front, right side cylinders had burned off all their insulation. These are brand new MSD plug wires :(. I have Doug's headers and side pipes on the 1978 pace car. Obviously my mechanic had poor luck routing the wires. Do any of you have suggestions or a diagram on best practices for plug wire routing? Shielding from heat? I appreciate any and all help. Crying shame as I really want to break her in....now at projected 435 HP with upgrades.

Please note, I do not blame or fault the mechanic. Murphy's law in effect on this one and I know he'll make things right.

Chris

It seems that maybe the wrong set of plug wires may have been installed...angled boots vs. straight boots or vice-versa.  Your headers may require the opposite boots of what was installed.  Maybe they need to be routed differently...tough to say without actually seeing it.  

  Hey, I appreciate the response ! Yes, I used the 90 degree MSD's as speced for the car with the HEI 90's on the power side. Routed beneath headers and am guessing needed more wire ties to pull them down further and tied off at each boot. I am unaware of other means of shielding the wires (you referred to them as, 'boots"? Any link available or a brand name? Seems to be adequate clearance with the plugs and boots just wire burn through. Wondering if I need to wrap the headers though I hate to as I had them Hot jet Coated with black ceramic.

Chris

Look at a Summit Racing catalog or their website and check out the section on ignition.  You'll find a number of products to consider.

  Roger that, much respect and thank-you.

Chris

Good for up to 2,000 degrees...

http://www.summitracing.com/parts/THE-14250/

Great Minds thinking alike on this forum. I just found those thanks to another member and will have them here by Wednesday.

My mechanic just brought over replacement wires (which was a very nice and appreciated gesture) and the C3 is now roaring once again. Awesome guy to come help me on a hot Saturday afternoon.

This is a great forum and I really appreciate the help you two guys have given me. I am looking forward to spending lots of time here.

Chris

Welcome Chris ... you will get great advice from this forum !

good luck with the routing of the new wires

Chris
Welcome, I just went thru this myself as both my vettes burnt plug wires this week. I found the shorty plug that is made by Accel. They are 1/4" shorter which doesnt seem like much but it get the wire farther away from the header. I also use a protective High heat boot, but with a standard plug length the boot still burns and causes issues. The 1/4" is just enough room to allow the wires not to touch. i bought the plugs at Advanced auto parts.
I hate that store but they had them on the weekend in stock. They also have boots as well
Good luck
Rodney Hake

Danscar burnt the wires at Carlisle the crew installed new one's with the heat shield cloth over the boots just before 17 of us went to dinner last night.