Spark Plug wires-gctid404211

[JimMc]

Does it make a difference what brand you use? I am looking to tune up my 5.7 Mercs with Thunderbolt Ignition.

These are some of the brand plug wires I have found.

Mercury

Quicksilver

Sierra

United Marine - Sold by Michigan Motorz

Spark Plugs

AC vs NKG ?

Any experiences would be appreciated.

[JimMc]

I am guessing no one has an opinion.

Or at least no one wants to make a recommendation. That I understand.

So

I ordered the United Marine Mega-Mag wires. The description sounds good, we shall see.

MEGA-MAG® WIRE BREAKDOWN 1. BRAIDED KEVLAR Kevlar® is the inner strength of the SSC low resistance core Kevlar® inner core is used in place of fiberglass for superior strength and durability Hundreds of strands are woven together to form this "Stronger than Steel" base which virtually eliminates inner core breakage; due to excessive pulling and bending 2. CONDUCTIVE OUTER CORE The braided Kevlar® core is layered 5-7 times with a highly conductive carbon latex Gives the SSC MEGA-MAG® core the suppression needed to eliminate static throughout all radio frequency ranges Guarantees current flow throughout wire lead; even under the most demanding voltage requirements 3. MEGA-MAG® SSC WRAP Special alloy wrap used to carry 90% of voltage to spark plugs Gives mega-mag SSC wire its extremely low resistance characteristics, which allows a hotter spark to be produced Allows faster current flow for longer spark duration 4. INNER DIELECTRIC BARRIER A high density layer of Ethylene-Propylene Diene Monomer (EPDM) is extruded over the SSC core to eliminate dielectric bleed-through from the low resistance high output MEGA-MAG® core 5. FIBERGLASS BRAID A tightly woven fiberglass net braid is used to form a permanent bond between the E.P.D.M. inner layer and the outer silicone jacket Greatly increases overall cable strength Locks terminal onto wire to virtually eliminate terminal pull-off 6. 100% SILICONE JACKET Provides the highest protection against chemicals, oil and abrasion Seals out corrosion causing moisture Used on ALL applications even when NOT specified by O.E.M. Features: MEGA-MAG® 8mm SSC silicone wire Ultra low resistance 250 OHMS per foot 3 Part Core 1. Kevlar® inner core 2. Carbon - latex outer core 3. SSC wrapped outer core 3 Part Insulation 1. High density inner jacket 2. 100% fiberglass braid 3. 100% silicone outer jacket Custom built wire set to fit your specific application Exceeds O.E.M. specifications

UNITED IGNITION WIRE Warranty Information United Premium Wires - Lifetime.

[Guest]

I didn't see your post and checked several times today.

Like I recommended to the other spark plug wire question the other day, Napa has a great set of marine wires for a decent price. Cheaper than I found online and they are good quality. They don't always stock them but bring them in quick. Like a day or two.

[Chief_Alen]

I didn't see this thread. I like ac plugs. Wires no opinion.

[JimMc]

Thanks guys.

[2850Bounty]

There are certain areas where I believe that we can turn to the automotive guys for test results, and perhaps spark plug wires are one of these.

Some of the discussions talk about steel conductors, of which we don't use due to RF interference.

Here's an ohm test that a LSM 1 forum member did. Warning: Long read.

I've always wondered how valid an ohm reading is for a conductor that is intended to carry high voltage with alternating current characteristics..... basically, one cycle per spark event!

According to these guys there are some substantial differences.... but read on.

Here are most tests and comparisons.

You decide if they are valid or not.

Here is a thread on the DMS Tuners forum.

I find this info interesting (taken from post #3):

What is not generally understood (or is ignored) is that as a result of the laws of electricity, the potential 45,000 plus volts (with alternating current characteristics) from the ignition coil (a pulse type transformer) does not flow through the entire the length of fine wire used for a spiral conductor like the 1 volt DC voltage from a test ohmmeter, but flows in a magnetic field surrounding the outermost surface of the spiral windings (skin effect). The same skin effect applies equally to the same pulsating flow of current passing through carbon and solid metal conductors.

Post #6 (perhaps the most informative post) is very interesting where this member explains "DON'T BE MISLED INTO THINKING LOWER RESISTANCE WIRES ARE BETTER!"

I think that he makes a very good point.

Be sure to read this post.

.

[Guest]

Not a recommendation but an observation.

As stated in the previous post, the high voltage spark pulse travels via the "skin effect", and this means that if the spark plug lead is not adequately insulated then when one spark plug lead physically touches another spark plug lead an effect called "cross firing" can occur. I.e more than one plug fires at the same time. This is particularly problematic on V8's (more wires) and when the wires are not kept separated - have a look at your Mercruiser set up and you will see the wires run together for a distance!

When I bought my boat (twin 350 MAG) the PO had fitted some aftermarket plug leads and the motors never ran correctly - rough idle, wouldn't rev out ... My mechanic investigated and plug leads were the problem. Replaced with Mercury part and all came good.

Re Dean

[JimMc]

It seems I pulled the trigger too quick on my purchase.

I did speak to Michigan Motorz and was assured the United Marine wires were high quality. Hmmm He told me they were the OEM supplier for a name brand. Knowing Michigan Motorz reputation I went with their recommendation since engines are their thing.

So much hype out there makes it hard to make good purchases.

[Guest]

jim they should work fine.

[Mileskb]

I noticed on my 470 that the four wires are 4 different lengths. This was done for aesthetics, but it's always bugged me. At the same time, I wonder if there is something in the design that they need to be 4 different lengths.

Of course, if they were all the same length, I'm not sure how I would route them to take up the slack.

[2850Bounty]

DeanB wrote:
Not a recommendation but an observation.

As stated in the previous post, the high voltage spark pulse travels via the "skin effect", and this means that if the spark plug lead is not adequately insulated then when one spark plug lead physically touches another spark plug lead an effect called "cross firing" can occur. I.e more than one plug fires at the same time. This is particularly problematic on V8's (more wires) and when the wires are not kept separated - have a look at your Mercruiser set up and you will see the wires run together for a distance!

Same here..... just an observation.

I think that cross firing is certainly a possibility if the plug wires are breaking down and are failing.

Consider the 8mm size. Most of this 8mm is the insolating characteristics (minus the conductor diameter).

Two cables laying side by side, effectively have an insulation value of 8mm (i.e., 1/2 of 8mm = 4mm X's 2 = 8mm again).

8 mm = 0.314"

The spark's best path will be the actual spark plug gap.

Spark plug gap = .032" to .045"

Is this an actual concern if the plug wires are in good condition?

Items like these always crack me up.

Forget cross-firing.... and look at the potential path here with these being steel!



BTW, if you've seen an old OMC stringer drive engine plug wire separators, they are excellent.

They're white plastic, and look similar to this, but are about 2" long.

The cables just snap into them.

If you come across any, don't toss them. They work very well.

Attached files http://baylinerownersclub.org/media/....jpg[/img]

[Guest]

My Volvo came with something just like that. It lays on top of the valve cover and keeps the wires separated.