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Autolite spark plugs gap too small?


iJimaniac

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So I have a set of Autolite Double Platinum APP105 plugs to install in my 4.0 OHV. Sticker on truck says proper gap is .052-.056. Current NGK plugs are gapped to .056. New Autolites are averaging .042 and the electrode is already curving upward (see picture). Plug box says nothing other than to refer to some elusive catalog for gap. Looked online and found no manufacturer recommend spacing of these plugs.

I'm concerned if I gap them to Ford's recommended gap the electrode will be way out of whack, and from what I understand that's not good. Are these even the proper plugs? Autozone and Autolite say they are, and I see multiple references here on the forums. Should I go ahead and gap them or just leave em at current gap?
 
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alwaysFlOoReD

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My wag is it would be fine.
 

iJimaniac

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alwaysFlOoReD said:
Subbed for knowledge.
My wag is it would be fine.
Click to expand...
To clarify, what would be fine? Sticking them in with .042 or gapping them to ford spec? I actually went ahead and gapped them to ford spec to see what they look like. Here's a picture;
 

RonD

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Yes, 0.054 is average gap for 4.0l OHV spark plugs, I would gap them at that.

Recommended gap for all gasoline engines is for average driving conditions, smaller gap is better for higher RPM driving, better coil recovery time.
Wider gap is better for lower RPM driving, stop and go traffic, pulling loads.
0.005 increase or decrease is fine, you can go as much as 0.010 one way or the other but it will effect high or low RPM performance.

So 0.049-.0.059 gap is fine depending on your driving needs
 
Mac

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Those plugs can be used in many Ford engines going way back to the Pinto, each may require a different gap. Gap per spec, they are not pre-gapped.
Dave
Edit: Just checked and the Pinto uses a .034" gap.
 
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