plug wire arching?


Senior Member
Lafayette, LA
My mechanic friends always warn me about plug wire arching and i'm not sure i understand exactly what they are talking about. Many tell me I should get straight boots on my plug wires...can anyone explain anymore...only thing i can maybe think of is that some of my wires are much longer than need be and rest on the frame before curving up to the distributor cap. Does this effect performance or idle dramatically?

75 Addict
85w/350 - a couple of things come to mind reading your post:

1 - they're talking about the wires either coming in contact with the exhaust manifolds/headers, (depending on what you're using) getting burnt, and grounding out as a result OR: deteriorating due to the heat from these components even if they don't actually touch. Possibly the reason they suggest straight boots is to get the wires a little farther from the heat - because a 90 or 45 degree angled boot turns right beside the manifold while a straight boot extends out in line with the plug.

2 - they are referring to misfire and/or crossfire problems from the wires touching each other or grounds such as your frame. In looking at a book on my shelf (Power Secrets by Smokey Yunick) it is suggested that each plug wire be kept away from any ground or other plug wire. It states a minimum of 1/2" distance - keeping in mind the book is geared towards high performance and they're referring to aftermarket ignition systems. This is pretty hard to do without some elaborate custom fabbing of wire looms, but the basic idea of keeping the wires separated and not touching grounds is a good one.

I don't think the actual length of your wires is a problem, but touching the frame sounds like it could be a contributing factor.

From what I understand, the misfire/crossfire problems will tend to show up under high load conditions, and may not even be apparent at idle.

Hope this can be a little help to you!