Question regarding spark plug gap
#1
#2
Gap them all the same. My stock plugs are supposed to be .054 as well. However, I installed Denso Iridiums and gapped them at .050 . I'm not sure if I would gap them that small, but I am not familiar with the Autolite 5144's. Where did you get the .044 gap # from? Was it for your vehicle specifically?
#3
Join Date: May 2004
Location: Georgia on my mind...
Posts: 6,509
Likes: 0
Received 6 Likes
on
5 Posts
The 4.2 is weird like that...see, one side of the ignition fires on the positive side, the other side fires on the negative side. When the 4.2 first came out, Ford specified two different spark plugs for that engine, so you'd have different plugs on opposing cylinders. They've since updated the plug to where there's only one plug, and it'll work for either side of the ignition. I'd split hairs and lean towards .050. Make sure those Autolites are like the latest Motorcraft plugs, in that it doesn't matter where you install them, that they can fire on either side of the ignition.
#4
#5
Join Date: Oct 2002
Location: St. Louis (Out in the woods)
Posts: 7,247
Likes: 0
Received 104 Likes
on
97 Posts
Originally Posted by Quintin
The 4.2 is weird like that...see, one side of the ignition fires on the positive side, the other side fires on the negative side. When the 4.2 first came out, Ford specified two different spark plugs for that engine, so you'd have different plugs on opposing cylinders. They've since updated the plug to where there's only one plug, and it'll work for either side of the ignition. I'd split hairs and lean towards .050. Make sure those Autolites are like the latest Motorcraft plugs, in that it doesn't matter where you install them, that they can fire on either side of the ignition.
Ford used single vs double plats on one side only as a cost savings measure during manufacturing. Saved a few cents on every vehicle by using the singles where they would work adequately.
All replacement plugs have always been the same type - first double plats, then fine wires.
Haven't heard of the Autolite 5144... but if you're usng the APP5144 (duoble plat), you should be fine.
As far as the gap, follow the recommendation on your emissions decal under the hood regardless of what Autolite says to use.
Steve
#6
#7
Originally Posted by Blonde Ambition
Steve, they are the APP5144's. The .044 specs were from the Kragen site when I looked up my plugs so it was vehicle specific.
I do have a torque wrench. I asked for one for Valentine's day once because I was rebuilding my Miata motor. Then I got tools for Christmas. I'm wierd.
I do have a torque wrench. I asked for one for Valentine's day once because I was rebuilding my Miata motor. Then I got tools for Christmas. I'm wierd.
Trending Topics
#8
Actually, English, that's a WOMAN with tools who changes her own plugs.
A *Girl* is a GUY who has no tools and is capable of only changing his own shorts.
But I do agree - that's just terrific to see. Bravo!
Getting back to plugs... try checking Denso's website - they have good install instructions. Note they mention different torque specs with and without anti-sieze. I favour the use of same, due to the dissimilar metals.
It's here: http://densoiridium.com/installationguide.php
Cheers
Vic
A *Girl* is a GUY who has no tools and is capable of only changing his own shorts.
But I do agree - that's just terrific to see. Bravo!
Getting back to plugs... try checking Denso's website - they have good install instructions. Note they mention different torque specs with and without anti-sieze. I favour the use of same, due to the dissimilar metals.
It's here: http://densoiridium.com/installationguide.php
Cheers
Vic