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Timing with an HEI distributor

Discussion in 'General Jeep Discussion' started by stanbo, Aug 27, 2016.

  1. Aug 27, 2016 at 8:52 PM
    #1
    stanbo

    stanbo [OP] Member

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    1974 CJ5. 4.2 258 inline 6. 3 spd manual.
    rear locker
    Does anyone know what the ignition timing should be on my '74 CJ5 with 4.2 L?
    I added an HEI distributor
     
  2. Aug 27, 2016 at 10:13 PM
    #2
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine Moderator

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    Does this help?

    upload_2016-8-27_22-13-28.jpg
     
  3. Aug 27, 2016 at 10:51 PM
    #3
    stanbo

    stanbo [OP] Member

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    rear locker
    Thanks Chris. To be more specific, how many degrees, at 650 RPM, does the upgrade to HEI change?
     
  4. Aug 28, 2016 at 9:05 AM
    #4
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine Moderator

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    I wasn't aware it changed anything.
     
  5. Aug 28, 2016 at 9:17 AM
    #5
    stanbo

    stanbo [OP] Member

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    rear locker
    Thanks, that would make it simpler!
     
    Bob likes this.
  6. Oct 5, 2016 at 7:56 PM
    #6
    OFFGRID

    OFFGRID Well-Known Member

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    Vehicle:
    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    I don't believe you change the timing. I believe it is 6-8* BTDC. I run mine at 8 BTDC with fuel injection. Don't forget to disconnet the vacuum when you set your timing.
     
  7. Oct 5, 2016 at 8:00 PM
    #7
    stanbo

    stanbo [OP] Member

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    rear locker
    Thanks Peter. Initially, I had it set at 9 but it pinged jnder load. I am at 5-6 now and its all good.
    One exception though, in the high country last week, the carb was loading up badly. Need to do something about thT before I go up again.
     
  8. Oct 5, 2016 at 9:01 PM
    #8
    OFFGRID

    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    I am in Houston. There is about a 100ft difference between the High country and the low lands. We call it a bridge. But to my knowledge if there is a big enough difference in elevation carbs need to be adjusted I think turning your screw in a 1/4 turn may help at higher elevation and adjustments made need to be made avery few thousand feet. The fuel needs to run leaner to make up for the thinner air. There are some videos on Youtube that address this issue Edit I'm not a carb guy. I've been running fuel injection since the 80s. Fuel injection makes its own adjustments.
     
    Last edited: Oct 5, 2016
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