spark plugs

[cumberlander]

what is a good brand of spark plug and wires to use?

 

[superranger4.0]

Factory plugs ang wires always work well. I run NGK plugs in mine.

 

[Bruce]

I just put the Autolite XP 5144's iridium in mine and what ever plug you use be sure to use anti seize on the plugs threads andonly remove and install when engine is stone cold.

 

[Sasquatch_Ryda]

Stick with the factory plugs and wires

 

[Bob Ayers]

Motorcraft double platinum, or fine wire platinum.

 

[AllanD]

Motorcraft AWSF42PP

accept no substitutes.

AD

 

[Big Jim M]

From time to time you will hear guys complaining bout this plug or that plug...cept for ONE PLUG! You will never hear a guy complaining bout the plugs that CAME in his engine.. Why take a chance? Get whatever CAME in that engine. I had to look in the manual and special order the correct plugs for my SOHC 4.0. But I got em..and at bout the same cost as the silly aftermarket plugs.
No plug is BETTER than the factory plug.
Big JIm

 

[gerko]

I hear Platinum only last longer.(?)

I can get 3 sets of AWSF 42 C very cheap

Is that a good substitution?

Thanks

 

[Big Jim M]

GERKO There is only ONE spark plug that is absolutely the correct plug! The one the factory put in there in the first place.. Changing FROM that plug CANNOT ever be any better..But it can be MUCH worse! Why take a chance on any other plug?
Even if you must order the correct plug...do it! Get what is known to be a PERFECT fit for your engine.
Big JIm

 

[rangerbert]

I agree get the factory plugs and wires for you truck.

 

[gerko]

thanks again for the answer guys!

 

[FoRdDaNgEr]

the only reason you would need to change anything relating to your plugs or wires is if you are plannin on runnig higher voltage through them, and increasing your gap.
no higher volts....no change

 

[Bob Ayers]

the only reason you would need to change anything relating to your plugs or wires is if you are plannin on runnig higher voltage through them, and increasing your gap.
no higher volts....no change

The plug gap is what determines the voltage, and there is no reason to use anything but the MFG recommended plug gap!

 

[AllanD]

The actual factory original plugs in most 4.0's are "unobtanium"

the factory (to save a little money) uses different plugs on the left and
right bank of the engine.

This is because that six tower coil pack is really only three coils
and the firing to one bank is reverse polarity.

the platinum isn't really "needed" on both electrodes
so on one bank the "tip" has a platinum button
on the other side the platinum button is on the ground electrode


However the specified replacement plug, the one I mentioned above,
The Motorcraft AWSF42PP is a "double platinum" plug specifically made
to work on EITHER side of the engine.

I guess ford figuires that the double-platinum buttons will prevent people
from putting single button plugs on the WRONG side of the engine.

AD

 

[Bob Ayers]

The actual factory original plugs in most 4.0's are "unobtanium"

the factory (to save a little money) uses different plugs on the left and
right bank of the engine.

This is because that six tower coil pack is really only three coils
and the firing to one bank is reverse polarity.

the platinum isn't really "needed" on both electrodes
so on one bank the "tip" has a platinum button
on the other side the platinum button is on the ground electrode


However the specified replacement plug, the one I mentioned above,
The Motorcraft AWSF42PP is a "double platinum" plug specifically made
to work on EITHER side of the engine.

I guess ford figuires that the double-platinum buttons will prevent people
from putting single button plugs on the WRONG side of the engine.

AD

Here is a schematic I made for the 3.0L coilpack, I'm sure the 4.0L is the same. You can see from this how 2 plugs fire in series, and each receive opposite polarity spark. The spark polarity determines which electrode will erode: