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Yet an other spark plug question

3K views 3 replies 3 participants last post by  Danny 
#1 · (Edited)
Ok, first off, I'm an idiot. now that that's out of the way.....
I changed my plugs the other day with the Champion 7318 double platinums without gapping them. Truck runs fine and smooth, and my mpg has increased by around 3 (old copper's were TOASTED). Well, I call Champion today to "verify" that the plugs came set to spec. and the tech told me that they have no factory set gap and could have all been at different gaps. I did some searching on here and someone here that used the same plugs said all of his came gapped at .045". Sooo...question is should I re-do? That is a .05" difference if mine came out of the box the same as his. Anyone else used the 7318's w/o gapping them, or am I the only genius here that's done that?:rofl::mofo:
 
#2 ·
All platinum plugs I know of are pre-gapped to a certain spec. because if you try to gap them yourself you will likely damage the platinum and drastically reduce the life. I used Bosch .044 in my upper bank on my 4.7 L. I'd worry more about getting the right thread length (depth of thread) than anything. I know that my 4.7 L takes a deeper thread, if you try to put in a more shallow thread plug you will not only not have the tip near where the spark needs to be, but as the engine runs over time the threads in the head (left uncovered due to incorrect thread length) will carbon up making them nearly useless. I've seen where this has happened and then the right plug (on the next change) won't screw in properly to the head. As far as gap goes, run what's recommended for the best gas mileage because over time gap widens as plugs wear....you don't wanna disadvantage yourself from the start with a wider than normal gap. Hope that helps.
 
#3 ·
If there were sleeves over the threaded portion of the plug they were pre-gapped.
The site, if I remember said .044.
Regardless, these plugs don't wear like the copper ones you removed and as such the gap will have barely changed at 80k.
I'm sure the plugs you removed were probably worn well beyond .060 and as you said, other tham MPG, it ran well.
These coils have no problem firing a plug out to around .080.

IMO....Leave em alone, it'll be fine.
Street engines really aren't that critical.
Now, if we were talking about a dragster my response would be different.

Rob
 
#4 ·
Thanks for the replies, guys; I appreciate the valuable info. I learn a lot from this place. I went to a parts store today and checked the gap on a brand new plug identical to the ones I used, and the gap on one read .039 and the others were all just over or under...the biggest being .043. The tech at Champion told me that they were not pre gapped to a certain gap. (No sleeve on the plug, Either).
 
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