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I've got a new set of plugs here to go in the 22. What I want to know is what should I set the gap too? They are just cheapo NGK's. I've heard 0.035". But when looking at the spark off the coil pack which is a good 2/3 of an inch long I was wondering if a wider gap could be beneficial? I ran both 0.055" and 0.035" and saw no difference with my EA81 and it's Mallory Pro Master coil.

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  • 11 years later...

.02: the wider the gap the better the combustion. From HERE:

Quote

Gap: Gap has a lot to do with igniteability. The bigger the gap, the better combustion. HOWEVER, this comes at a cost. The bigger gap requires MORE voltage to spark, puting a much higher strain on your ignition system. With a turbo charged motor, the gap is usually smaller. This is due to the fact that higher cylinder pressures make it harder for the plug to fire, therby increasing voltage requirments (this is why 2.5L NA is 0.044" gap and the 2.5L turbois 0.030" gap). Can your ignition system handle the increased load?? Good question. 

So, run the widest gap you can that doesn't cause issues - knock,  etc. 

 

Remember the MFG recommends what works for all their vehicles and commonly available fuel....doesn't mean it's optimum for YOUR car.

Edited by wtdash
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On 8/22/2018 at 6:14 PM, 86BRATMAN said:

If I remembered my reasoning from over a decade ago I'd surely tell you. 

Lol, fair enough!

I bought the NGK BKR6E-11 plugs, which are actually the recommended plugs from the factory service manual (I just recently downloaded). And yea the FSM recommends a gap between .039 and .043. 

I checked the NGK's gaps with feeler gauges and they are all at .042 dead on. I don't think I'll bother trying to gap them one more thousandth, but maybe. 

Cheers ya'll

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