Rear Wheel Drive Newsletter March 2010

The Technology Behind ipd Plug Wires

By Rob ArnoldSpark plug wires may not be as exciting as turbochargers, downpipes, or air intake systems but they are just as critical to proper engine operation and performance. Believe it or not spark plug wire technology has actually progressed, albeit slowly, over the years with little to no fan fare. So in an effort to give spark plug wires their 15 minutes of fame, let’s take a look back at how they’ve evolved over the years and what those changes have done.

In the early days of automotive engines, spark plug wires had to simply provide a conduit for the spark energy to reach the spark plug. With such a rudimentary job the wires themselves were quite rudimentary in their design; typically no more than a solid copper wire that connected the spark plug to its respective terminal on the distributor cap. It wasn’t long until insulating material was added to aid in combating misfires as the ignition components wore, but this basic design was around for a number of years and worked quite well for its time.

Fast forward to the early adoption of electronics to the automobile, namely radios. It became apparent that the high energy from the coil that transmitted through the solid plug wires created significant radio frequency interference. Manufacturers responded with a myriad of solutions, the most successful was limiting the spark energy through added resistance. This was done in a few ways, primarily through resistor type spark plugs and through a design change in plug wires. The change in plugs wires was from the previously used solid core wires to a carbon impregnated fiber wound wire surrounded by a rubber coating. This resulted in an increase of resistance in the plug wire which resulted in reduction in spark energy and aided in reducing the amount of RF that was transmitted to the radio. This became even more important as fuel injection systems came to market.

Fuel injection systems rely on a number of electrical signals fed to the ECU so that it can then inject the correct amount of fuel given the current needs of the engine. Many of the sensors used in fuel injection systems work on a lower signal range than the vehicles normal operating voltage of around 13 volts. Typically they will provide a 0-2 volt signal for the more critical signals like crank position or in some cases cam/distributor position. These signals are more prone to stray electrical energy and are therefore designed to use shielded ground wires that help capture and direct any stray RF in the engine bay. The ignition system is the primary cause of RF in the engine bay and as such, the design of spark plug wires must yet again be revisited. This time around, engineers found that if the carbon impregnated fiber was wound in a helix fashion it would make the wires act as pseudo inductors ‘holding’ the spark energy in a magnetic field rather than broadcast it like a radio antenna. This was helpful not just to the lower voltage signals found in the fuel injection system but also in the ABS systems that were becoming more and more prevalent.

Unfortunately, by and large, all the design changes to spark plug wires over the years haven’t contributed to increased spark energy but rather reduced it. This is undesirable from both a performance and efficiency standpoint, however the aftermarket has seen this and responded in kind. The sharp increase of available materials for plug wire construction has helped tremendously where we now see spiral wound wires with silicone jackets more common place and helping to bring back some of that lost performance and energy. ipd’s wires are no exception, with the same spiral wound technology and advanced material use, we are able to bring to market wire kits that offer original equipment fitment with greater energy transfer, all the while keeping unwanted stray RF energy at bay. Our 8mm silicone jacket helps reduce the likelihood of misfire meaning better transmission of spark energy to the spark plugs and increased performance and efficiency. If you’re looking for the best for your Volvo or maybe it’s simply tune up time and you want a higher performance wire kit, we’ve got the answer for you!

Ignition System Care

By Rob ArnoldCaring for your ignition system typically involves just replacing worn components. But to get the greatest life span from these components a little care should be exercised. Spark plug wires are generally composed of an inner core that carries the spark energy and an outer sheath typically made of silicone. Although silicone is mostly impervious to gas and oil, if exposed long enough they can begin to break down and get a mushy consistency. This will develop into an engine misfire at worst or poor mileage at best. Another crucial part of the plug wire is the boot that prevents the spark energy from jumping around the spark plug to ground. High heat levels, grease, and oil can all cause boots to fit poorly allowing for plug arcing. Be sure that plug wire boot ends are clean and do not wiggle on the end of the plug. If you do find oil or gas contamination, resist cleaning the wires or boots with a solvent based cleaner, instead use a clean dry cloth and wipe the residue from them. Caring for your plug wires is one sure way to maximize your maintenance dollars.

Now let’s talk about those spark plugs. There are a number of plug gapping tools available on the market today and while most spark plugs come pre-gapped is a good idea to at least check them before installation. From manufacturer to consumer a spark plugs trip is a long one, and throughout its journey it is subject to some abuse. Since gapping is checked in the thousandths of an inch (i.e. 0.028) a small impact makes a big change. In addition, one spark plug part number may fit multiple engine configurations to which each may have a different gap. Checking gap is easy enough but which type of tool is the easiest and most useful? We have found that the bucket of gap tools on the counter of the local parts house to be the worst in general. These half dollar shaped units are often inaccurate due to the inherent sloping edge used to measure the gap with. A better design is the graduated wire style. This gap tool has multiple wire diameters that are common gap specifications. By using this tool you can be sure that the gap across distance of the plug electrode is consistent whereas the style previously mentioned has a certain inaccuracy because the sloping edge only contacts the far edge of the plug ground strap. Wire gap tools also include a ground strap adjustment wrench. This allows minute adjustment without having to ‘smack’ the plug against the concrete. Although these tools typically sell for around $4-$5, a far cry from the $0.25 units at the parts house, it’s a far better value

Spark Plug Wires by ipd

Our custom spark plug wires are made with a high quality 8mm silicone jacket and feature a spiral wound core for maximum electrical efficiency. Each wire set is custom designed for each application covering over 40 years of Volvo models. Engineered to meet and surpass OEM quality, our wire sets include factory style metal end connectors (where applicable). Each wire set includes spark plug and coil wires as well as dielectric grease used on the plug boots for easy removal at tune-up time.

Original Equipment Spark Plug Wires

by Bosch and BougicordA properly tuned ignition system is one of the most important factors of any engine. It will keep your engine running smoothly, economically and will deliver the most power. The increased heat under the hood may lead to premature degradation of the ignition wires. These wires are made by the original equipment supplier to Volvo so you are assured of the best quality in replacement wires.

NGK and Bosch Spark Plugs

The first suspect in a poor-performing engine always seems to be the plugs.

On overhead cam engines one should expect about 30k miles but, as these are getting older, they are wearing out sooner too. Contaminants such as oil and incorrect fuel mix will shorten the life of a plug dramatically.

We have been using and selling NGK spark plugs since the seventies because they’re the leaders in copper core technology. Copper is a great conductor of electricity and heat, so copper spark plugs perform well under all extremes and have a large conductor tip for maximum spark area.

Spark Plug Thread Repair Kit

If you have a 1976-1995 4-cylinder Volvo with marginal or damaged spark plug hole threads, you can now make a quick, professional repair in minutes without removing the cylinder head. Kit includes everything needed to permanently repair 2 spark plug holes. Works on all B21, B23 and B230 engines. Remember that you can reduce the chances of this happening by using a small amount of anti-seize compound on the spark plug threads every time the plugs are replaced. Kit contains 1 specialized reamer tap, 2 thread inserts and locking compound.