Ignition Wiring - Secondary Thoughts

Not everyone wants to run a big 8 or 8.5mm plug wire, for both performance and aesthetic reasons. In this case, something along the lines of the 7mm Stock-Look wire from PerTronix will cater to their needs by providing the necessary low resistance and high suppression in a factory-looking disguise.

Among the vintage-looking ignition wires currently being used these days, there's a bit of discrepancy among the core construction of each. From top to bottom: NOS cloth-wrapped (copper) solid-core, '60s-era carbon-core, cloth-covered spiral-wound, reproduction cloth-wrapped (insulated stainless) solid-core, and reproduction silicone-housed solid-core.

Shown are the two examples of lacquered/cloth-wrapped wire: on the left, Vintage Reproduction Parts' new 7mm wire with silicone suppression layer insulating a stainless strand core; to the right is the solid-core NOS wire it's modeled after. Along with the added suppression benefits, the reproduction wire features a much heavier exterior coating.

There are spiral-wound versions of the cloth-covered wire available out there for those running an aftermarket electronic ignition such as an MSD 6AL or PerTronix Igniter series. Make sure you have the appropriate core type before installing any vintage-looking wire, as a solid-core will ultimately damage ignition components.

With the reproduction Standard Motor Products 7mm wires (available through Speedway Motors and Mooneyes), it's "clear" to see what you get. There should be no confusion regarding what type of wire this is.

Along with the vintage look of the ignition wire itself, there's also the terminal end to consider. It's important to provide enough added resistance (varies on vehicle particulars) via the terminal, which is one of the reasons Vintage Reproduction Parts uses quality rubber boots.

The Raja terminal is still quite popular, but as you can see, leaves little in the way of concealing the spark once it reaches the plug, thus the higher potential of cross firing.

More concealed versions of the Bakelite or plastic terminals are available (mostly in straight configuration) and, for the most part, relatively inexpensive. That said, the cheaper ones tend not to hold up very well over time, as evidenced by the connectors losing their "grip".

With the exception of being used on stock points-style ignitions (or with a magneto), I've found these types of terminals to work best as-is ... on the shelf along with other hot rod curios and keepsakes!

For any ignition system above and beyond the OE norm, a spiral-wound inductor-type wire is required, at least if you want to actually get all the performance benefits out of your ignition. No other type of wire can transmit optimum spark with such high suppression characteristics.

There's a broad spectrum of induction-wound wires available today: from high-end 8.5mm MSD Super Conductors all the way down to ACCEL's 5mm Ferro-Spiral wires.

It's helpful to know the difference in terminal ends, at least if you're planning to install a universal set of plug wires...

... Typically, a manufacturer will supply their wires with the plug ends already installed, so the end user is left with the distributor side, either HEI or standard.

When it comes to HEI terminals, there are different crimp types, as shown here. MSD uses the dual-crimp style, while many other manufacturers still use the single-crimp...

...With the dual type, the wire core doesn't need to be folded back when crimped.