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External or Internal HEI? *Ignition Ques. added now*

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by ChevyCaGal, May 26, 2001.

  1. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Ok....I need to ask this to be sure. I'm going to have to replace my ignition. Long time ago when it was broken into they messed it up. I managed to get it working again but it's on it's last legs that is for sure. I figure replace the whole set up and go from there... however, I honestly am a bit confused on the whole external and internal HEI? How do I tell which one I have? I'm going with a Jacobs most likely.....the Mileage Master Energy Pak. Any help is appreciated. Thanks! [​IMG]

    Steph

    "Suck Fumes Ford Boy"
    "I love my country, I fear my government"
    <A target="_blank" HREF=http://www.chevycagal.homestead.com/steph.html>http://www.chevycagal.homestead.com/steph.html</A><P ID="edit"><FONT SIZE=-1>Edited by ChevyCaGal on 05/29/01 01:55 PM (server time).</FONT></P>
     
  2. K5RON

    K5RON 1/2 ton status

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    Re: External or Internal HEI....?

    Correct me if I'm wrong but the internal/external thingy is the location of the ignition coil. If you have a separate coil, it's external and if the coil sits atop the distributer, it's internal. Hope this makes sense!

    Ron
     
  3. coopertwpk

    coopertwpk 1/2 ton status

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    Re: External or Internal HEI....?

    I would strongly recomend not going with Jacobs go with MSD they will back their products unlike Jacobs also the internal hei is not the way to go get a newer style 87 up external coil eType the module inside is more reliable and the pickups are better also a MSD system is less expensive,also most racers use MSD not jacobs .

    88k5 silverado w4"lift soon to have <font color=orange>d44 and corp14ff</font color=orange> with 4.56s
     
  4. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Re: External or Internal HEI....?

    Thanks...figured it out! [​IMG]

    "Suck Fumes Ford Boy"
    "I love my country, I fear my government"
    <A target="_blank" HREF=http://www.chevycagal.homestead.com/steph.html>http://www.chevycagal.homestead.com/steph.html</A>
     
  5. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Re: External or Internal HEI....?

    I have an 86, so the 87 and up I believe wouldn't work for me correct?

    As far as MSD goes they cost just as much as Jacobs does. I've been pricing around. I think different people have different luck with stuff. I'm willing to take my chances with Jacobs. MSD lost me from buying due to beyond poor customer service I recieved. They could give me a free set up and I'd throw it away. Rude individuals is all I can say...I won't support that....

    "Suck Fumes Ford Boy"
    "I love my country, I fear my government"
    <A target="_blank" HREF=http://www.chevycagal.homestead.com/steph.html>http://www.chevycagal.homestead.com/steph.html</A>
     
  6. coopertwpk

    coopertwpk 1/2 ton status

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    Re: External or Internal HEI....?

    as for price how much is your jacobs system? I only need the ignition so MSD is only 150 and jacobs wanted over 400 also no one around here even stocks jacobs systems I can go to my local shop and deal directly with them.

    88k5 silverado w4"lift soon to have <font color=orange>d44 and corp14ff</font color=orange> with 4.56s
     
  7. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Re: External or Internal HEI....?

    What set up did you end up going with and buying? I'd like to know so I can see it and just compare features. Thanks!

    "Suck Fumes Ford Boy"
    "I love my country, I fear my government"
    <A target="_blank" HREF=http://www.chevycagal.homestead.com/steph.html>http://www.chevycagal.homestead.com/steph.html</A>
     
  8. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Re: External or Internal HEI....?

    coopertwpk- I don't know if you missed my reply, but I am curious on what set up you bought and are running? MSD guy was freaking rude to me...but I can get a set up discounted because I complained and they "wanted to make up for that." But anyhow I don't like them due to that...but if I can get a deal then maybe I can see past it...

    This is for anyone... I want the Jacobs Mileage Master set up... what does MSD or anyone for that matter have that compares to that and is about the same? Thanks! [​IMG]

    "Suck Fumes Ford Boy"
    "I love my country, I fear my government"
    <A target="_blank" HREF=http://www.chevycagal.homestead.com/steph.html>http://www.chevycagal.homestead.com/steph.html</A>
     
  9. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    or you can go buy a MSD box to replace your modulator in your old Dist. then a new cap coil and internal parts. new wires and plugs. i bought all of that for 250. and mine runs like a champ....

    1974 Chevy Blazer Cheyanne. lots of plans for it....
    but it is on 33's now, with saggy old springs. i am in so cali if ya got any parts for me.
     
  10. KENT

    KENT 1/2 ton status

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    Check out Crane. I have been hearing alot of talk about them being better than MSD and cheaper that Jacobs. A friend of mine went with Jacobs and was disapointed by the performace gains, but loved the customer support.

    Kent

    1989 K5
     
  11. CaptCrunch

    CaptCrunch 1/2 ton status

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    Re: External or Internal HEI....?

    CCG... I have the Offroad MSD box, MSD Coil, and helicore wires from MSD w/ NGK plugs gapped at .060. Even w/ my terrible gears and high milage motor I have seen a mpg increase of 1 to 2 mpg and a tad bit more power. If you think MSD are jerks wait till you get to Jacobs guys... I have heard some really bad stories and have yet to hear a good one that isn't in a Jacobs funded article. Through summit the msd box is $220, the wires are $50, Coil is like $30.... way below the price of the Jacobs... plus the multi spark or whatever they call it from jacobs where it fires several sparks per a second instead of one full power spark a second (to increase power, emmisions and mpg) is what the offroad box uses. If you really hate msd that much try crane. My buddy has run them w/ great results in his Mustang for a while now. Jacobs is overpriced, overated crap IMO... much like 4WPW LMAO [​IMG]

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <A target="_blank" HREF=http://www.geocities.com/milnerlives_2000/blazer.htm>http://www.geocities.com/milnerlives_2000/blazer.htm</A>
     
  12. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Re: External or Internal HEI....?

    AHHHH ok, I think I'll just leave it. My brain can't handle this. I hate to feel stupid but I simply am way too confused here to do this yet. I'd like to do it myself but it took me all day to change spark plugs. Putting in a new ignition might kill me... Reason I wanted the Jacobs system was the fact I have seen one out of the box and read the directions. I can install it- may not be in an hour, but I could do it. The MSD- holy cripes! It was Chinese to me... made no sense and you had to order everything seperate. Don't they simply sell something along the same lines is a Jacobs? A complete set up where someone like me who has no clue what all to order can do that? I know that may sound dumb... but I'm learning as I go and I get lost easy... and most of this tech talk is still way confusing which is why I am so lost here..... [​IMG]

    "Suck Fumes Ford Boy"
    "I love my country, I fear my government"
    <A target="_blank" HREF=http://www.chevycagal.homestead.com/steph.html>http://www.chevycagal.homestead.com/steph.html</A>
     
  13. Blue85

    Blue85 Troll Premium Member

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    Re: External or Internal HEI....?

    You should be able to order any of them with connectors to plug right in place of the existing stuff. All you are really doing is running the signal from the pickup coil (which site inside the distributor, around the shaft) to whatever ignition box you are running, supplying it power and running new spark plug wires. I don't believe that any of the brands are really any more difficult than any others. The module inside the stock HEI distributor really just amplifies pulses from the pickup coil and uses them to drive current through the primary winding of the coil. Then the secondary winding is connected to the rotor, which spins and gives the spark to the appropriate spark plug wire.

    Plus, if you get confused with the directions, you can always come on here and ask some questions. Whether you choose Jacobs, MSD or Crane, you can find somebody who already has one working on their K5.

    Something else to consider is getting an ignition with a rev limiter, to prevent blowing the engine if you break a driveline part. Kind of cheap insurance, really.

    <font color=green>Why does everyone worry about my gas mileage, but not think twice about an Excursion owner?</font color=green>
     
  14. CaptCrunch

    CaptCrunch 1/2 ton status

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    Re: External or Internal HEI....?

    Well CCG blue is right... they are pretty much the same install wise. The toughest thing about the whole deal is where to mount the box. I know MSD very well so I can pretty much tell you anything you need to know and can always take pics of my setup if need be. Basically you hook 2 wires up to the battery terminals and then About 2-4 where the coil is. If you want even simplier you can get the msd adapter (I'm assuming you have a coil on cap setup w/ an 86) so you can run the old school style coil. WAY EASY thene... just crimp on terminals and go. If you want some one to assist w/ what to order and/or install let me know. I'd be glad to help. I would really hate to see you get the jacobs.

    Another thought is the HEI setup is pretty good already.... I don't know what you mean by fry the ignition systems... but you could probably get a msd coil and a Holley performance module... then gap the plugs .060 and get pretty darn good gain in performance. Easier to install and nice and simple... cheaper too [​IMG]

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <A target="_blank" HREF=http://www.geocities.com/milnerlives_2000/blazer.htm>http://www.geocities.com/milnerlives_2000/blazer.htm</A>
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    Theres not much you can do to the distributor to mess it up. It would be either visibly obvious, or only a couple of easily replaceable electtrical components. I seem to be in the minority with my dislike of MSD, Jacobs, etc., but test after test has proven that the power gain is negligible. Ease of starting, and extremely high (some say 4500, the magazine dyno test I read said 7000) RPM use are where the MSD would come into play.

    Yet being in the minority, using some stock HEI dist I bought for $20 (don't even know what it came out of, was sitting on a truck seat when I found it), no new cap, no new rotor, but newer wires and plugs, I get 15MPG freeway, 10-13 city, carbed. I know I can get more out of the carb, I am going to lean the primaries out a bit, because I know its running rich, but still...

    I would be willing to be that without changing ANYTHING, except adding an MSD box, I would notice nothing, or next to nothing, in mileage or power increase.

    In other words, replace any worn/questionable components, make sure everything else is ok (distributor advance weights aren't sticky, etc.) and be happy ; )



    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen
     
  16. Josh

    Josh Registered Member

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    Take a look at this website. I'm thinking of using this instead of MSD. I have talked to their tech people and they seemed pretty knowledgable and friendly. Only problem is they are in FL and I'm west coast so you have to call at the right time.

    http://www.cranecams.com/ignition1/igntech.htm

    Josh
     

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