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Discussion Starter · #1 ·
Just wondering what the effect would be if someone had gapped their plugs to say 50 and they are supposed to be at like 80? Does it effect performance or does it just make the plug hotter/colder? Just curious.
 

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Is this a specific engine your talking about or just a general question about plug gaps?

I'm not familiar with any engine that has a 0.080" spark plug gap spec, aside from maybe a top fuel car.

Larry
 

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Discussion Starter · #3 ·
Not really specific, just wondering what it would do. But, i did get the number .080 from my 455 Olds.
 

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A bigger gap = longer spark = "more time for the fuel to burn a little more completely...." I do not know where the area of diminishing returns occurs in this equation...... I do know that i pulled a set of plugs outta a ford 3.8 awhile back, gap was sposed to be .060". it in actuality was almost twice that, .118", and the motor was running fine. just needed a tune up.:confused:
 

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I need a spark plug gap for a gm 350 crate motor.I think its suppossed to be .035.Not sure.Thats where you guys come in.Thanks bm
 

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Increasing plug gap will slow timing by a tiny bit due to increased energy required to generate an arc over the wider gap. Additionally, if plug gap is increased and the ignition system is not fairly strong, at high RPM/high cylinder pressure the engine may missfire. Also complicating this is the issue that dwell time can only be so long in the high RPM so that the coil may not be able to produce the energy to generate the arc with the shorter dwell.

Long story short........plug gaps are specified for a reason.

Chris
 

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I'm running autolite 24's at a plug gap of .035 with an msd ignition system on my 406. The have a light tan to brown color to them which I think is good. Just my 2c
 
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