Replacing spark plug wires probably won’t be the most glamorous upgrade you’ll perform this year, but it’ll help bridge a critical gap in the ignition circuit between great and poor performance.
While several wire manufacturers are available to choose from, this month we chose to use a set of MSD 8.5mm Super Conductor wires. If you check out the MSD catalog, you’ll find that it holds an extensive collection of pre-assembled and universal wires, including the classic red and the more subtle black versions.
For our small-block–powered ’67 Chevelle, we chose the red set with 90-degree boots (PN 31239, $95.95). Experience has shown us that the 90-degree boots are the safest bet, however, individual boots of other angles are sold if you run into a one-wire exception. The owner had already decorated the engine bay with red MSD electronics, so these wires would be right at home.
The ’67 started out with a set of MSD wires that were badly burned due to poor routing. To avoid a similar situation, we’re going to show you how to keep the wires away from danger, all the while producing an extremely clean look. Starting out with the universal set gives you the freedom to be creative in your routing design. With this freedom also comes the responsibility of assembling the wires correctly. MSD recognizes the potential difficulty of getting the correct crimp on the un-terminated ends and offer their own ratcheting stripper/crimper to handle the task. To further ease assembly, they also carry Spark Guard (PN 8804 $15.95) in their product lineup, which is dielectric grease that doubles as an assembly aid. It also ensures that you can easily pop a wire off the top of the cap down the road while keeping the voltage in and moisture out.
Rather than fitting each wire by marking, removing, assembling, and reinstalling it, we opted to install them once and crimp them while they were on the engine. This way we didn’t run the risk of not being able to re-create the same fit the second time around. With our sneaky under-header mounting, keeping track of which wires were which would be difficult without the numbered wire collars that are supplied with the MSD wire kit. One worry with universal kits is choosing the incorrect wire length for a particular plug, only to be stuck with a piece that was too short at the other end. By using the method shown here, there’s little concern for length because even the shortest wires were plenty long.
From the time we started disconnecting wires to pulling out of the garage for the test cruise, just over an hour had passed. It’s also important to note that the Chevelle came in with an intermittent miss that disappeared with the fresh set of wires. With the right tools and a plan, we gave this engine bay a new clean look and added performance at the same time.
The crimpers that do it all
The MSD crimpers aren’t just for assembling spark plug wires; it has several removable jaws for different connectors. Not looking to buy a new tool? MSD includes a crimper in each kit to use in your bench vise.