Hot rodders don’t live in a “one-size-fits-all” world. By nature, we love customization—whether it’s a custom paint job, one-off aftermarket rims, or a radical resto-mod project. So it’s no surprise that more and more performance enthusiasts are electing to custom-build their own spark plug wire sets.

You can, too!

This installment of Summit Racing Quick Flicks shows you how to build your own spark plug wires and covers:

  • Custom spark plug wire components
  • Tools you need to build custom spark plug wire sets
  • How to properly assemble a custom spark plug wire set

Why settle for a set of ill-fitting, off-the-shelf spark plug wires when you can get a perfect fit and finish with your own wires? Watch now!

To assemble a set of custom spark plug wires, you are going to need three tools—a pair of wire snips, a set of crimpers or dyes which may be included with the set of wires you purchase, and spray lubricant to get the boots on the wires.

There are three steps to assembling your custom wire set. Step one is to cut the wires to length, step two is to crimp the ends on, and step three is to install the boots.

When you take the wires out of the box, the wires are going to be pretty long to start with, and you are going to notice that the boots are already going to be assembled on the wire for the spark plug ends. The reason for this is so that you can cut them to the specific lengths necessary for your application.

Whether you are running a set of wire looms or are going to zip tie the wires in place on your application, or whether you’re going to run them under or over the exhaust manifolds, it is best to go ahead and set up the wires and do basically a dry fit. That’s because the spark plug boots are already on the wires you can go ahead and put them in place. Route them in the position you want them for your specific application and then cut them to the specific length necessary for your set up.

Now that your wires have been cut to the proper length, the next step is to crimp your wires. Before we can do this, it is important to understand what type of crimped ends you are using there are two versions available, you are going to have a single crimp end and a double crimp end. We are going to go ahead and explain how to crimp both of these types of terminals on your wire set. The first style of a crimped end I’m going to show you how to install is a single crimp type end which is probably the most common in the industry today and comes with most type of wire sets.

The first thing you are going to do after cutting your wire to length is go ahead and strip the end of the wire. So we’ll take our crimpers here and you’re probably going to want to leave three quarters of an inch of the wire lead hang outside the wire after its been stripped. Your crimpers will have a stripper attachment in the dye assembly to make this possible. So let’s crimp down on here. You typically want to crimp down twice or you will end up buckling it on the end and will probably have to twist it off. You’re going to want to see a lead something to this length.

Next, you will want to fold the wire lead over and place the terminal end on the wire making sure the wire lead coincides with the backside on the terminal. Then, you will want to take your crimpers and you will notice they have a defined end on them that are supposed to coincide with the open end of the connector. You place those on the terminal and crimp it down into place. What you will end up with is a connection like that. The installation of the dual-crimp connector in comparison to the single-crimp connector is slightly different starting with the way the wire is stripped. The dual-crimp connector requires that less wire be exposed when the wire is stripped to be placed in the connector. Your crimp tool will have a dye in it designed specifically to show you the depth of which the wire should be stripped.

So what you will do is take your wire assembly, place it in the dye crimper and basically make it flush to the end of the crimper assembly, crimp it down into place and you will see that is now only going to expose roughly a quarter-inch of the wire in comparison to about three quarters of an inch or so with the single crimp connector.

Unlike the single-connecter type terminal a dual-type terminal does not require the wire end be bent over. Instead, it is just placed right into the connector and you want it to coincide with these two tangs here on the connector itself. Then what you will do is take your crimpers and on the end of your crimpers you will notice that you have these two jaws that are a little different than the rest and place them around the end that is encompassing the wire. Crimp it down and you will notice it caught the wire assembly. Then you will take your crimpers and place them like your single-connector connection and crimp them in the normal location and that gives you the dual-connector connection.

The final step to assembling your wire set is placing the boot on the wires. To do this, it is best to have some type of non-flammable lubricant or maybe some liquid soap to go ahead and lubricate the pieces so they go together very easily.

I’ll take some spray lubricant typically and will spray the inside of the boot as well as the end of the wire so they do not bind up against one another. Spread it around here, then we will go ahead and slide the boot over the end of the wire assembly to the point where you will be able to see the terminal through the end of the boot. Now that your custom wire set has been assembled, they are ready to be installed on your vehicle. 

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Author: David Fuller

David Fuller is OnAllCylinders' managing editor. During his 20-year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In 2012, he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.