spark plug gap

Discussion in 'Chevy Truck Forum' started by smokensteve, Jan 21, 2008.

  1. smokensteve

    smokensteve Senior Member

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    What are peoples opinion on pre gapped spark plugs...had an argument with a friend about them...I always gap my plugs when putting them in an engine..also, what are some things that can happen to an engine with the wrong plug gap?....thanks for any info
     
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  2. gmtech

    gmtech Senior Member

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    I'm with you always check and adjust gap. biggest problem with not checking the gap is when it is too small you have improper spark and can cause a misfire
     
  3. junior3382

    junior3382 Senior Member

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    Timming in todays motors are so percise that the gap is very important. Off my a bit can cause a significant lag in timing and power. As for pregapped plugs, it depends on the plugs. Like the Bish Platinum +4's, you do not have a choice but to get them pregapped. in that case, I have noticed a difference in performance, but not enough to justify the cost. If it is a single prong plug though, I woul gap my own, just because I would be **** enough to make sure it was done right.
     
  4. smokensteve

    smokensteve Senior Member

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    yes... It doesn't make sence to me "pre gapped" unless all engines that that paticular plug fits, all have the same gap, how can they say they are pre gapped...like I'm sure the pre gapped plug will fit several engines not just one...so all those engines would have the same gap
     
  5. o3shortbed

    o3shortbed Senior Member

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    i always regap my plugs. the platinum plugs tend to last so long (100k on my 03 chevy) that it makes since to try and keep them as close to the specs. as you can
     
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  6. lonestar1128

    lonestar1128 Full Member

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    in my personal opinion, the bush +4 (4-pronged plugs) aren't woth the money. in addition they are "pre-gapped" but not necessarily properly gapped. I change my plugs once a year, needed or not, and i've been thru several sets of plugs that claim to be pre-gapped. However, i've never bought a full set of 8 that were all correct.

    My recommendation: ALWAYS check them yourself, and don't waste money on plugs like the +4 that you can't fit a gapper in. Most auto parts stores sell plug gappers for $0.75, too cheap and easy not to do it.

    Edit: A properly gapped plug will be wide enough to burn hot, but not so wide that it skips or misses at high speeds, causing that cylinder to drag, or the engine to begin to rattle. -Wikipedia
    Spark plug - Wikipedia, the free encyclopedia
     
  7. fbhart@wk.net

    fbhart@wk.net Senior Member

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    lonestar1128:

    You change plugs every year, I have 79K on my 350 engine and have never changed plugs.

    Old truck still starts and runs good, however, I was wondering how difficult it is going to be removing the plugs. Maintenance schedule says 100K I think.

    What is best plug to replace with, ones currently in truck have been good.

    If I replace plugs should I also replace wires and distributor cap, rotor, etc:.

    Also, what about shocks, they have never been replaced, how long do they usually last?
    Truck is a 3/4 ton and rides like a log wagon anyway, so who would know if they need replacing.

    Thanks, for suggestions;
     
  8. 1979_4x4_Plow

    1979_4x4_Plow Senior Member

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    i use ac delco plugs in my truck, but i think the truck had original plugs in it from when it was new in 1979. either way, the truck is happier and sounds & runs better

    if you do plugs, get wires and a decent cap that has brass tips. i go with accel cap and rotor kit sice it is better quality and cheaper to get t than the cap and rotor separate.
     

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