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RCB Samba Member
Joined: September 05, 2005 Posts: 4143 Location: San Francisco-Bay Area
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Posted: Sun Jun 07, 2009 1:59 pm Post subject: An old wifes tale or not |
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I was reading various posts here on The Samba and a post caught my eye.
In it...it says that the plug wires should not cross over each other or in any way touch each other.
As someone who learns from the wiser Im curious as to if this could cause a problem of any kind if the wires touch or overlap one another.
If it makes a difference I use the Bosch Super Wires part number 09171.
Thankx all |
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SteveVanB Samba Member
Joined: June 01, 2008 Posts: 1645 Location: This side of Daytona
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Posted: Sun Jun 07, 2009 2:05 pm Post subject: |
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For what it's worth, I have mine twisted aroung each other and it doesn't seem to affect anything. _________________ 91 CARAT |
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?Waldo? Samba Member
Joined: February 22, 2006 Posts: 9752 Location: Where?
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Posted: Sun Jun 07, 2009 2:49 pm Post subject: |
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It's an interesting thought. Any pulse of current will create a moving magnetic field which induces a current in the adjacent wires. I'm not sure how dramatic the overall effect would be but there is a factual basis. |
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Mr. Electric Wizard Samba Member
Joined: August 07, 2003 Posts: 2846 Location: Smyrna, TN
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Posted: Sun Jun 07, 2009 2:57 pm Post subject: |
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Wive's tale or not I do not know, but I just replaced my plug wires and plugs (bosch ultra premium wires - NGK BP6ET plugs) and it is running really, really well right now. My wires touch each other too. _________________ "Saying what we think gives us a wider conversational range than saying what we know."
~ Cullen Hightower
(T)exas (C)oalition (B)uses
(H)eidenhammer (B)ully (B)oyz
--1966 De Luxe Camper |
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Alan Brase Samba Member
Joined: March 28, 2004 Posts: 4532 Location: Cedar Falls, Iowa
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Posted: Sun Jun 07, 2009 3:01 pm Post subject: |
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Andrew A. Libby wrote: |
It's an interesting thought. Any pulse of current will create a moving magnetic field which induces a current in the adjacent wires. I'm not sure how dramatic the overall effect would be but there is a factual basis. |
Darn little, I'd guess. Perhaps enough to feel it if you ran a piece of hookup wire along the ignition wire and held onto both ends. There is not really very much energy going thru the wire, so it would be hard to lose very much.
(Unless you ran it thru a transformer, i.e. many turns and around an iron core.)
Al _________________ Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home |
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mcsyncro Samba Member
Joined: September 23, 2005 Posts: 193 Location: wherever subarus aren't
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Posted: Sun Jun 07, 2009 3:06 pm Post subject: |
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Back it the day, when engines had copper core plug wires, and plain
old rubber outter covers, the wires could cross fire if they we're touching
together. But these days with silicone outter's and carbon inners, it's
not much of an issue any more. |
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Volksbulli Samba Member
Joined: January 30, 2006 Posts: 364
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Posted: Sun Jun 07, 2009 8:40 pm Post subject: |
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mcsyncro wrote: |
Back it the day, when engines had copper core plug wires, and plain
old rubber outter covers, the wires could cross fire if they we're touching
together. But these days with silicone outter's and carbon inners, it's
not much of an issue any more. |
Exactly... hah, some old tractors I have worked on have the old copper wire wires and you don't want to be touching them while its running either. _________________ It's a Volkswagen Thing, Even I Don't Understand!(o\|/o)
-------------------------------------------------------
82' A/C Westfalia
67' Typ 1
96' Golf GL |
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VWGeorge Samba Member
Joined: July 10, 2004 Posts: 342
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Posted: Mon Jun 08, 2009 6:30 pm Post subject: |
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In the old days the RUBBER jacket on the SOLID COPPER CORE wires would rot and crack. In the event that the wires were crossing themselves would cause cross firing and the engine would run like shit if it got wet. |
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regis101 Samba Member
Joined: July 28, 2005 Posts: 2078 Location: Livermore, Ca
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Posted: Mon Jun 08, 2009 7:04 pm Post subject: |
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And by the same token, If you're into attention to details, It's one of the things that may prevent any future problems to pop up. _________________ Peace, Regis |
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tencentlife Samba Member
Joined: May 02, 2006 Posts: 10078 Location: Abiquiu, NM, USA
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Posted: Tue Jun 09, 2009 8:59 am Post subject: |
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Regardless of the wire core type (whatever it is made of, it has to carry the same level of power), any insulation will break down over time. There are factors that cause plug wire insulation to break down even faster, one being the high voltage itself, also the presence of strong magnetic fields (alternator, coil, and field generation in the wire itself) , heat, oil residue, and with anything except silicone the ozone gas present in any engine compartment. Of all these, ozone damages all kinds of rubber materials, natural and synthetic, faster than all the other factors combined, which is one good reason to choose silicone wires because it is one of the only materials suitable for insulation that shows little damage due to ozone.
Loss of spark energy can and will occur as the insulation breaks down. This is why you do need to replace the wire periodically. At tens of thousands of volts, electron pressure will find its way thru and ionise the air around the wire itself to seek a path to ground; that is why you can evaluate the condition of your wires by spraying a mist of water over them in the dark, showing visibly how much energy is escaping. Sometimes it's bad enough that you don't even need the water to see the blue sparks.
So any place you allow that energy an easier path to ground is a potential loss of sufficient power on that wire to jump the plug gap in the pressurised combustion chamber. At a certain point, and under certain conditions, enough is lost that there is no spark or only very weak spark at the gap, and that is a missed ignition. The conditions vary from stroke to stroke in the engine, which is why ignition misses are so variable and condition-dependent.
Any place you offer an easier ground path is a chance that a misfire can occur. A wire's voltage can jump to another wire if they are bundled together and their insulation is weakening. The plug gap in an unpressurised cylinder offers much less resistance than the one that should be firing, so some of the energy may jump to an adjacent wire to find ground that way, and that is a loss of spark energy in the cylinder that should be firing. If wires are in direct contact with grounded metals, there is a particularly easy path for spark energy loss.
So, no, it's not a wive's tale. When wires are brand new, if they are of good quality to begin with, they can contain the spark voltage effectively and little is lost, but they age inexorably, and as they do more and more spark voltage can be lost, up to the point that the losses prevent a spark from occurring where and when it should. So it's best to keep your wires isolated from each other and from grounded components as much as is practical. And even when that is done with care, you still need new ones periodically. _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9940 Location: Orbiting San Diego
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Posted: Tue Jun 09, 2009 10:15 am Post subject: Re: An old wifes tale or not |
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As these 2 images show, lots of German vehicles come from the factory with the installed plug wires run bundled together in a tube, touching each other willy nilly. BMW 3 series 6 cyl, Audi 5 cyl
http://www.autohausaz.com/secure/PartImages/12121705714.jpg
http://www.autohausaz.com/secure/PartImages/09500.jpg
Mark
RCB wrote: |
I was reading various posts here on The Samba and a post caught my eye.
In it...it says that the plug wires should not cross over each other or in any way touch each other.
As someone who learns from the wiser Im curious as to if this could cause a problem of any kind if the wires touch or overlap one another.
If it makes a difference I use the Bosch Super Wires part number 09171.
Thankx all |
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