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Insulating spark-plug wiring for improved performance

Insulating spark-plug wiring for improved performance

Wayne Scraba Mar 30, 2005
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Even the world's finest ignition wires are at the mercy of two things:the ignition system and, of course, Mother Nature. As ignition powerbecomes stronger and spark-plug gaps increase, the chance of sparkleakage through the wire casing increases. In today's cars, severalissues are at play: High-powered ignition buzz boxes are common,particularly in performance applications. As a result, almost all wiresare susceptible to voltage leaks and crossfire (our apologies to '82 and'84 Corvette owners). Also, engine compartments are more and morecrowded.

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This sleeve from Moroso (the company calls it "Blue Max") follows thetheory that the sleeve must be closely woven and further protected by alayer of silicone on the outer surface. This sleeve material is designedto seal the wire completely.

Because of these factors, there is less airflow around the spark-plugwires, and the added heat wreaks havoc on the wires. But there's more:Corvette enthusiasts are a serious bunch (or at least, we take our hobbyseriously). Many of us tend to push our equipment harder and, at thesame time, expect more out of that equipment. In simple terms, it'stough to tolerate something as "insignificant" as a set of bad wiresruining our fun.

The same applies to heat. Too much of it means the wires canself-destruct, usually at the most inopportune time.

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This is a new sleeve configuration from MSD. The design is similar tothe earlier woven-glass configuration, however, the exterior shellconsists of a special silicone-rubber coating. The inside diametermeasures 3/8 inch, which allows it to slide easily over most ignitionwires. MSD claims its Pro-Heat Guard has a core that can resisttemperatures up to 1,000 degrees F.

There's an answer to this dilemma: a spark-plug-wire sleeve. For theuninitiated, a sleeve is an add-on insulator that effectively protectsyour wires from the engine's high-heat environment and ignition system.There are a couple of schools of thought when it comes to wire sleeves.One maintains that a closely woven sleeve with a silicone outer jacketis best suited for the job. The other maintains that the sleeve shouldbe capable of breathing so it doesn't trap moisture between the wire andsleeve. In either case, the sleeves do their job.

Typically, sleeves can add 8,000 volts of extra insulation, add almostdouble that figure in crossfire "insurance," and offer a profoundresistance to heat created by headers or exhaust manifolds found intight engine compartments. Sound interesting? If so, check out thefollowing photos. We'll show you the process of installing the sleevesover a set of wires, and how to seal them to the spark-plug boots anddistributor- cap boots.

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Since the sleeve isn't a tight fit over the wire (generally speaking),some system of sealing the sleeve to the boot must be incorporated. Tosolve this problem, Moroso came up with a large-diameter "shrink sleeve"arrangement. The blue shrink material fits partway over the boot andextends partway over the sleeve, sealing the wire sleeve to the boot.

It's not a painful operation and it works.

Parts Department

Manufacturer/Description/Part Number

MSD/ Heat Guard wire sleeve kit/ 3408

MSD/ Shrink Sleeve kit/ 3409

MSD/ Pro-Heat Guard wire sleeve kit/ 3411

MSD/ Shrink Sleeve kit (Pro)/ 3407

Moroso/ Blue Max sleeve/ 72000

Moroso/ Blue Max shrink sleeve kit/ 72030

Moroso/ Blue Max numbered shrink sleeves/ 72020


Moroso Performance Products
Guilford, CT 06437



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