Spark Plug wire problem

I have a stock 350 small block chevy with Sanderson Headers that now needs a 3rd set of spark plug cables in two years. The problem is that the boots (which are suppose to be able to handle 600 degrees F) are in near contact (within 1/8th - 1/16th of an inch) of the header. I can't keep one or more (two this time) wires or boots from being damaged by heat and therefore causing problems with shorting to the block. This summer the engine rarely got over 170 degrees (thermostat rating) and always ran fine until a short occurred, this last time coming home from the Blue Suede Cruise in Norwalk, OH. I came home on 7 cylinders.

I have found that Accel offers an Extreme 9000 ceramic wire rated for 1000-2000 degrees (depending on whose website they're offered on).

Are these good wires? Is there another alternative I should be considering?

Thanks in advance

 

You could use 454 stock shielding devices that they use on big trucks. It is a metal flange that goes between the plug and the block that sheilds the plug and wire fron the exhaust manifold.

 

i agree or take some header wrap and put it around the boots.

 

Click here: Spark plug boot heat shield

 

Shorter plugs?

 

I have the same problem on #'s 5 and 6 on a set of Sanderson block huggers. Going to try and find some shorter plugs that is compatible with my currant new ones. (Autolite AP605)
The problem there is I’m not to keen on using Accel plugs. Any ideas here?

 

shorter plugs worked for me, as well as building the plug wires to size, and using the correct boot's.

good luck

 

.......and the make & number of the shorter plugs you were able to use succesfully is...?

 

how are you routing these spark plug wires? i've used a lot of headers...including Sanderson block huggers....and have never burnt a wire on the header. do you have angle plug heads ? pictures?

 

I have had the same problem, only worse. I came home from a short trip and had mine on fire with flames. I tried special boots, tape, and 3 different sets of wires. I have a 350 with 13/4 Sandersons and it is a real problem. I run a magneto, so i bought steel core wires from Hunt and its working for now, but I don't trust it for a long trip.--TV

 

Did anyone call Sanderson about this?

 

I took the AC plugs in to Vato Zone, or wherever, and x-referenced to an Accell plug.
I had/have my doubt's about the plugs, but they helped a bunch with clearing plug wire and header issues

 

What you are seeing in these photos is #6 on the left and #4 on the right. #4 has a good 1/4" clearence but #6 has less than 1/8" and the boot has been trimed to get that. You also can not get a deep socket on #4 to remove the plug as well as #5 on the other side.

 

That's what I have, except I am currently having problems with #6 & #8 plugs. I tried the spark plug heat shields and they worked up until recently, they are really difficult to get on with the plugs being so close to the headers. I think I will try the Accel ceramic plug wires and if they eventually fail I will put back the Ram exhaust manifolds I took off and go back to what I had. I am now using a quarter inch socket with a variety of extensions to get at all the plugs. Additionally, not all the bolts holding the headers on are easy to tighten/torque, I have fought several times with the bolt #2 on exhaust plug #2.

 

change the headers

 

As far as headers you might want to try early 60s corvette headers for SBCs

 

First thing I would do is take those pretty stainless braided covers off the plug wire. Why is that on there??? I would think that would cause some spark issues.


As to fix the problem, get the boot shields as mentioned in post #4. Ive used them before, and like the way they work, but they are kinda "race car" looking..........but work well.

 

Clearance the damned tube. First thing to do with new headers is check that the gasket surfaces are flat, then check the fit. It is not uncommon to have to dimple tubes next to bolts also.

 

I would think that if you buy quality goods from a major supplier that they would have designed them to work. But guess not. Sanderson designs theirs to be leak free and machined flat to fit with out gaskets. I put some in anyway.

 

I run the Accel shorty plugs and they work fine. I've used them on plenty of engines and never had an issue. The Accel plug catalog offers cross references.

This is typical on angle plug heads, since not many headers are made for them.

 

Jacobs makes wires with ceramic boots. I have a set on a tow vehicle for over 6 years, silicone wires would only last 9 months on that truck. Accel shows ceramic boots also, might be the same wires.

 

Put some timing in it!