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plug gapping

Discussion in 'The Garage' started by unick, Jan 2, 2004.

  1. unick

    unick 1/2 ton status

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    I got some new plugs and they are gapped to .045. Is this gonna be a problem or shouold I move them down to .035? Also how do I regap them? Do I just bend the tip down?

    LMK
    Nick
     
  2. unick

    unick 1/2 ton status

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    I just looked on the AC Delco website and they say NOT to gap rapid fire plugs. So now I know and so do you. /forums/images/graemlins/thumb.gif


    Nick
     
  3. Thunder

    Thunder 3/4 ton status

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    If its for your 87 TBI. Gap them at whatever the emission sticker in the engine compartment says the plug gap should be.
    I gap my TBI plugs at .050 but I have a pretty hot ignition.
    Most stock TBI ignitions will work anywhere between .035 and .045. Sometimes Gapping the plugs to the wide end of the range helps gain a little fuel MPG.

    And Yes. Just bend the electrode to gap them.

    Just saw your second post. didn't know they were Rapid Fires.
    Yeah you aren't susposted to re gap Rapid fires or Platinium plugs either. The guage can break the center electrode unless they are gapped with a round wire guage using care not to nick it.
     
  4. R72K5

    R72K5 Banned

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    you want .045 with all stock HEI anyways, so.,., although some of the 1975 engines(mainly oldsmobile) called for .060" gap, that was first year of the HEI system
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    Early HEI Olds were .080", then it was moved down to .060" until the end of the olds V8, 1990.

    Some GM V8's (I think it may have been the HO 305's, not 1975 IIRC) also gapped at .060" for one or two years, but then dropped back to the "typical" .035"

    Why Chev gaps that small I'm not sure, but the coil that runs a .060" gap and .035" are the same AC Delco part. I ran my 1974 SBC 350 at .060" for quite some time, and noticed no advantage or disadvantage, FWIW. Obviously there are pros and cons to wider vs. narrow gaps, but I didn't notice one either way.
     
  6. Confedneck

    Confedneck 3/4 ton status

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    gapped my 86's carb'd 350 plugs at .057..
     

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