Here At Scott Performance Wire, we offer American-made spark plug wires for winning race cars in NHRA, NASCAR, SVRA, and everything in between. We offer many different ready-made sets of wires for a variety of applications, from boat engines to coil wires. However, if you are in the market for a custom-made set of wires for your project with specific lengths, we can do that as well.
To make the correct length of wires for your application, here is your simple guide on the easiest way to measure and determine the lengths for your custom set of wires.
First, determine the way you want to run your wires, Whether you are running them under the exhaust or over the valve covers. Another aspect to keep in mind is the style of loom or wire separators you choose to run because they also affect length.
There isn’t a wrong option when deciding which routing option, it is up to you to decide what is the best way to route your wires so they won’t come in contact with the exhaust and be well restrained away from linkages and other looms.
Measure with Spark Plug Wire:
If you already have an existing wire that you need to be replicated, The most accurate measurement will be the total length from tip to tip of the spark plug wire. We will be able to match next to perfectly the length needed from this.
Measuring WITHOUT a Spark Plug Wire:
If you don’t have existing wires to measure from, the easiest way to get the right length is to use the “clothesline method.” First, we recommend you get around 25 feet of clothesline because they kind of simulate a spark plug wire. Use the line to mimic where you want the wire to run, you can include whatever loom or retainers you have to best match what your real wires will do. Tape each side of the line from the point on the distributor terminal and the tip of the spark plug and cut off the excess. From there measure that length off of the engine and from tip to tip and record that length.
Make sure you have no obstructions and keep a little bit of slack in the wire so that it isn’t too short. This measurement will be simulating center to center length. Repeat this process for every wire needed.
For our custom wire sets for this type of measurement, our wires will be within a 1/4 inch of the lengths you provided. (this discrepancy is for the boots and the angle and cap style given)
Other Measurements and Requirements:
We request that you measure your coil wire the same way if you need one for your car.
Determine what style cap you are running on your car, whether it is a male HEI or female style
If you have any further questions be sure to give us a call at704-664-9700 and we will get you set up!