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Boxer Ignition

Discussion in 'Boxers/TR/M' started by DonB, Oct 12, 2018.

  1. DonB

    DonB Karting

    Nov 11, 2003
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    Don Bartz
    #1 DonB, Oct 12, 2018
    Last edited: Oct 12, 2018
    Hey guys. My '84 BBi, 51723, like a lot of others has had the Marelli AEC104B-660 ignition box replaced with a MSD unit. In fact I'm on my second as the first failed after quite some time. It was an Off-Road unit and is no longer available and was manufactured prior to Holley buying MSD.

    IMO, MSD products, at least the 6 and 6AL are not what they used to be quality wise (as evidenced by the reviews on Amazon...FWIW). I've done some looking and have found an alternate to the MSD unit. It's the Pertronix Digital HP.

    I talked to Marvin in Tech at Pertronix, sent him wiring diagrams provided by Adrian at Dinoplex.org ( a wealth of information) and he said the conversion is a slam dunk. The factory coil will work too which is important for originality.

    The Digital unit, unlike MSD, provides multi-spark through the entire RPM range, is adjustable in duration (?) and the voltage output is also adjustable as well. The RPM limit is adjustable too.

    I think the adjustable voltage output might be advantageous for the following reason. As some might be aware, the distributor cap on BB's fail often. Especially if they're aftermarket repro's. Tom Meadows at Marelli Service told me that because of heat, and the high concentration of Ionized air in the cap, the cap is subject to considerable stress. When you consider the original Marelli unit only put out one spark per cycle, thus one transfer of spark from the rotor to the cap contact, degradation of the contact surface was "normal". As an aside, Adrian at Dinoplex.org said the Marelli unit put out as much energy as an MSD unit, but obviously only one spark.
    With the above in mind, if there are multi hi power sparks going across the contact points it would seem to make sense that the surfaces would degrade even faster (if I'm all wet on this let me know...I have thick skin). With the Pertronix unit. Even though there would be multi sparks thru the entire RPM range, if the voltage could be adjusted downward, perhaps that might lessen the wear on the contact points. Lesser voltage but over a longer duration?

    The price point is very competitive too at about $220. The unit is much more compact than the MSD as well.

    SO, by chance has anyone out there used one of these units? I think I'm going to make the switch and see how it goes.
     
  2. samsaprunoff

    samsaprunoff F1 Rookie
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    Jun 8, 2004
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    Good day Don,

    I have not used one of the Pertronix units and so I cannot provide any first hand experience. That being said, some of the marketing items they present certainly look interesting, but may have caveats attached to them. I say this, as there are laws of physics and limitations of our engines that may limit what Pertronix's box is doing. That is not to say that Pertronix is not doing it better than MSD, etc, but one must realize that they are simply using known and established circuitry to achieve their goals. In other words there is no "secret sauce" to their box. With that said, it is great to have another alternative to the original Marelli unit and the MSD boxes. I would not hesitate to give the Pertronix unit a try, as I, too, have had issues with MSD's product. In fact it does seem that the newer MSD units are not made to the same level/quality of the earlier units. This is unfortunate and is somewhat common these days where firms diddle with good products in order to manufacture them at a lower... with the results being that the newer version is not as good as the original.

    Cheers,

    Sam
     
  3. Newman

    Newman F1 World Champ
    Professional Ferrari Technician Owner Consultant

    Dec 26, 2001
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    A pertronix unit was recently put inside a dinoplex for a boxer im restoring. I can see if some pics can be posted.
     
  4. DonB

    DonB Karting

    Nov 11, 2003
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    Don Bartz

    Thanks guys! Appreciate the response. The nice thing about the Pertronix unit is it's size. About 1/2 of the MSD unit so it's easier to "hide".
    FYI, I have found out that the Marelli unit CAN be repaired..this from an excellent reliable source. However, I still have my doubts because of the potted construction of the Marelli unit. The unit would come from Europe, is not cheap, and, what would one do about warranty..if there is any? Seems like too big a gamble.

    After I get the Pertronix unit going I'll be sure and post an update.
     
  5. samsaprunoff

    samsaprunoff F1 Rookie
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    Sam Saprunoff
    Good day Don,

    Repairing the old Marelli electronics is not something I would do, as the original Marelli electronic design has a number of issues/flaws and is a dated design using dated components. Secondly, as you mentioned, removing all of the original potting material would not be easy and could create its own issues. To me removing the old Marelli guts and replacing them with a modern equivalent makes the most sense from a cost, reliability, and originality perspective.

    Cheers,

    Sam
     
  6. DonB

    DonB Karting

    Nov 11, 2003
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    Don Bartz

    I agree!
     
  7. turbo-joe

    turbo-joe F1 Rookie
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    romano schwabel
    if you buy it from a shop then this shop has to give you minimum 2 years warranty. if within the first 6 month the unit will fail the dealer has to proof that the unit has been ok when he sold it. but this is nearly never possible. so he has to change it. and if the unit will fail within the other 18 month he then send this unit to the manufacturer and they repair or send a new one. for free only if they see that the unit has not been manipulated and not wrong connected. that is the law here
     
  8. Newman

    Newman F1 World Champ
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  9. DonB

    DonB Karting

    Nov 11, 2003
    96
    Florida
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    Don Bartz

    Thanks!
     
  10. Newman

    Newman F1 World Champ
    Professional Ferrari Technician Owner Consultant

    Dec 26, 2001
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    Just to be clear, the pertronix doesn't come with a sound generator.
     

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