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Can a broken spark wire cable be fixed?

Discussion in '308/328' started by RichardAguinsky, Jul 24, 2009.

  1. RichardAguinsky

    RichardAguinsky Formula Junior

    Nov 12, 2007
    477
    Palo Alto, Californi
    Full Name:
    Richard Aguinsky
    #1 RichardAguinsky, Jul 24, 2009
    Last edited by a moderator: Sep 7, 2017
    Oops! Little accident in the garage with one of the spark plug wires. Not sure how it happened. At least it was not the distributor cap that got hit or stepped on.

    It's a 1984 Mondial, US version.

    I'd like to replace that single wire for now. It's cylinder one.

    There are posts mentioning 7 mm silicone spark plug wires from Kragen or other parts store, though they do not feel like the same quality as the broken wire. Or am I being too picky?

    Any leads are greatly appreciated. Thanks in advance.
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  3. mwr4440

    mwr4440 Four Time F1 World Champ
    Rossa Subscribed

    Jun 8, 2007
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    I would NOT try to repair it. Would cause NOTHING but problems IMHO.

    If you do not care about the color (his are black) call DaveHelms, a member here.
     
  4. 275 GTB

    275 GTB Formula 3

    Nov 21, 2008
    1,304
    Sthrn Highlands
    I don't see why not...the leads aren't moulded into either end...they just seem to be pushed through...use some good quality leads though.
     
  5. GrigioGuy

    GrigioGuy Splenda Daddy
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    Nov 26, 2001
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    Easy. Unscrew it from the distributor end, pop the other moulded end off the other side, go get some rolled spark plug wire with the same resistance and diameter (I don't recall what I used) and some crimp ends, and simply replace the wire inside the red cover. I -think- I used 45 degree angles on the crimp ends but it's been a while. A lot of spray lube was required to get the wire back in the red cover.

    Any good auto parts store that still has parts people can work this out for ya.
     
  6. RichardAguinsky

    RichardAguinsky Formula Junior

    Nov 12, 2007
    477
    Palo Alto, Californi
    Full Name:
    Richard Aguinsky
    #5 RichardAguinsky, Jul 24, 2009
    Last edited: Jul 24, 2009
    The cables are simple to disassemble. The boots can be pushed out. The spark plug lead can be a simple 45 deg angle one bent to match the boot. The problem is that the thinest silicone cable I found is a bit tight for the red covers. Though I see that other owners had to deal with the slightly thicker cables, I'll follow their advice.

    Does anyone know how many ohms per foot the original cables were? I can't find the specs for Cavis 400 Classe B anywhere on line. The only mention is in eBay for an old set.
     
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  8. 275 GTB

    275 GTB Formula 3

    Nov 21, 2008
    1,304
    Sthrn Highlands
    If you have some good leads in the set...just measure their resistance with a multimeter and use the average of those as a benchmark???
     
  9. mwr4440

    mwr4440 Four Time F1 World Champ
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    Mark W.R.
    Opps!!

    My bad I guess. I thought you meant to repair the wire itself not the wire "package." (boots, ends etc.). :(
     
  10. RichardAguinsky

    RichardAguinsky Formula Junior

    Nov 12, 2007
    477
    Palo Alto, Californi
    Full Name:
    Richard Aguinsky
    I tried measuring the ohms, but I am getting open circuit on all the wires. Maybe it is my digital multimeter. I found a local ignition wire shop that can make one with high performance silicon wires. Interestingly enough, he measured the diameter of his wires and they vary from color to color. Which is what I noticed with the wires at the stores. I don't mind the color, as I will use the original jackets and boots.

    The question is still how many ohms per foot. I can't find the Covis 400 specs anywhere on line. Anybody knows the ohms/ft?

    The more I look into making the custom wire and the more I read about posts regariding failing extenders I am now considering making wires with long boots (as my Land Cruiser) and take out the extenders. Has anybody tried this?
     
  11. fastradio

    fastradio F1 Rookie
    Professional Ferrari Technician BANNED

    Apr 26, 2006
    3,652
    New England
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    David Feinberg
    But, here's a summary of what's going on and how to properly repair your car:

    The Cavis wires (original equipment) are junk-Always have been, always will be...
    The fail internally, as you have seen, over time.
    Or, they'll fail at the (poorly) crimped factory connectors
    Or, they'll "burn through" where the piercing screws contact the wires at the distributor cap
    And...likely, as one wire of your has broken....the other will certainly follow.

    Repairing "just one" wire will ensure that you'll be doing this same repair again shortly...

    Ignition wire selection on the cars equipped with Digiplex units is critical. Although the engine will run with a generic, off the shelf Shelp Boyz or Wal-Mart wire, the possiblity of odd-misfires due to EMI issues is real. The extenders are not a troublesome component. They are a maintenance item, just like every other component in the ignition system. Time not miles drives the replacment intervals...Prolonged high temperature will cause any dielectric material to eventually fail.

    So, to fix your car correctly, the first time, here's how I would approach the problem:

    Purchase 8 new extenders:
    -Source A&W Auto Parts in NJ
    -PN: 126699 (These are the "Euro-spec" extenders without a resistive core, so the failure rate approaches zero)
    FYI: Ditching the extenders on a 3.2 is a bad idea...

    Purchase or fabricate a new wire set: The desired resistance is 450-650 ohms per foot!
    -Source Ferrari (OEM Cavis-Junk and expensive)
    -Source Kingsborne (Complete set, ready to install) Quality-Decent, Price-About 30% less than the Ferrari junk
    -Source Magnecore (Send them your old wires set...they;ll install their wires in your old sheathes and plug connectors)
    -Bulk wire (Must be of a spiro-core design, else the EMI issues will drive you crazy...)

    ->>>>The best quality sources: Dave Helms custom bulk wire, Taylor 7mm spiro-core, or myself as I roll my own wire sets)
    This will require you to snake the 7mm Cavis wire out of the sleeve...and crimp on a new end for the plug connector (MSD stainless steel variety). The only special tools you'll need are a can of silicone spray to ease installation and a "pro-grade" wire crimper.

    This is how I repair these cars...and there are many, many happy owners who are on this board that will sustaintiate that this method works effectively...

    Best,
    David
     
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  13. 275 GTB

    275 GTB Formula 3

    Nov 21, 2008
    1,304
    Sthrn Highlands
    Dunno...but something around 18Kohms for a single lead (obviously not a wire cored one!) has to be in the ballpark????
     
  14. JoeZaff

    JoeZaff F1 Veteran
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    Aug 5, 2007
    5,403
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    #11 JoeZaff, Jul 31, 2009
    Last edited: Jul 31, 2009
    C'mon boys, maybe you need a refresher course, what you need is a set of 30 weight ball bearings, some 3-in-1 oil and some gauze pads. And your gonna need 'bout ten quarts of anti-freeze, preferably Prestone. No, no make that Quaker State.
     
  15. climb

    climb F1 Rookie

    Sep 19, 2006
    4,717
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    Stuart K. Hicks
    For $32 the accel 4040 wires are excellent. They have between 3-5 ohm resistance per foot. The 8mm end goes right into the distributor with just a little soap and the other end goes right into the extender. The boot fits snugly over the accel end.

    They even sell individual ones at discount auto parts for $5.
     
  16. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    5,817
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    Mike 996
    Before jumping into ignition wires, read this. It IS from magnecor, who is trying to sell you their wires but it is an excellent treatise on wires, how they work, and some of the bizarre claims that wire makers make/have made. It's most refreshing to hear a manufacturer (Magnecor) state that their wires WILL NOT ADD ANY HORSEPOWER to your engine. This is, of course, absolutely true but many wire makers want you to believe that their wires can induce some sort of breach of the laws of physics! :) It's good stuff and based on my experience in engine building, I'd say it is absolutely correct and verifiable by unbiased testing. No, I have no connection to Magnecor and don't have them on any of my vehicles.

    http://www.magnecor.com/magnecor1/truth.htm
     
  17. fastradio

    fastradio F1 Rookie
    Professional Ferrari Technician BANNED

    Apr 26, 2006
    3,652
    New England
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    David Feinberg
    We're not selling snake oil here...or making claims of "increased HP". All of the above wires will "make the same" HP. The problem with the Ferrari ignition system, specifically on the cars with dual spark boxes, is that EMI induced mis-fires/crosstalk between the two independent systems is a real potential problem. And...that the coil wire from the 1-4 runs parallel to the TDC/crank sensor lead is just asking for trouble. Are there any EEs out here that remeber what happens when you run a high vlotage, non-shielded wire next to another one?

    Don't agree? A quick search reveals many concerns relating to mifires at specific engine speeds...


    At that resistance, suspression is minimal....and EMI-realted misfires are a real possibliity.


    Agree...I run Magnecore 8.5mm wires on my BB. A great company to work with, without all the hype. I sent them a new Cavis wire set (for testing and analysis) that seemed to think that a 12-cylinder car was only supposed to tun on 9-cylinders. Evidently those crafty Italians didn't quite understand about the crimp connector had to be connected to the wire. HA!

    These cars get hot under the bonnet. A quality wire is important for long-term durability.


    David
     
  18. davehelms

    davehelms F1 Rookie

    Jan 3, 2004
    4,629
    Full Name:
    Dave Helms
    If there is enough spark to light off the mixture...thats all that needed. Secondary concerns are like David stated, will that spark also light off other cylinders due to RFI and how long will they last in the extreme enviroment of a Ferrari engine bay where a gentle hand at removing them is often a lot to ask.

    When all is said and done there is a very small price difference between most of the choices, this is a very poor area to save $20-30 if there are better choices. This spring I had a QV towed in with steel core wires installed.....all wrapped with tin foil. I was put in a position where I had to suggest that there were better uses for tin foil... maybe for the turkey, hats....
     

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