haven't been working on my car nor computer for a while, but now i need to change spark plugs (just as maintenance) and heard that a 4.9 doesn't like platinum spark plugs, difference is that mine runs cng, so would i best buy normal copper, platinum, double platinum or iridium spark plugs for my car?

 

Motorcraft or Autolite copper.

 

Since the 4.9L doesn't use waste-spark ignition, where the plugs see opposite polarity spark, single platinum plugs will work just fine.

 

This may be true, but for some reason the 4.9 doesn't like platinums.

 

Motorcraft BSF-44C (copper) or BSF44P (single platinum) should work fine.
The platinums should last longer than the coppers.

 

I'm tellin ya from experience, platinum spark plugs do not run worth a hoot in the 4.9L. I wasn't even impressed with a 302 truck that had them that I picked up. Nothin' but Motorcraft for my rigs.

Adrianspeeder

 

^^^I'll 2nd that.
Ditch the platinums. (They may last longer, but platinum is not as good a conductor as copper)

Whether in my bro's '88-4.9L, or my '89-5.0L, Motorcraft coppers, or NGK V-Groove copper plugs performed the best.

 

motorcrafts copper it will be then, now find a supplier nearby thanks all

 

Motorcraft BSF44CF6 (SP-435) $1.42 each (1.11 euros) @ rockauto.com. Gap to .044.

Rock Auto has a EU warehouse and will ship to you.

 

rockauto ships to me but it all comes from US. wich means +-25$ shipping costs, if i dont find the plugs here i will look what i could order with it.

 

Hey johny, what is cng? Thanks, Peace, Dave.

 

http://lmgtfy.com/?q=cng

 

That's pretty funny, I like that.

Adrianspeeder

 

Hello, I did google that, and came up with alot of conflicting info on what spark plugs to use for compressed natural gas and gasoline. Since there were 7 replies, none of which said you can use x spark plug for cng and gas, I figured I would have johny clarify what cng was. Worse come to worst, he could replace the plugs with whatever was in there originally. Sorry for trying to strike up a dialog on a forum. Peace, Dave.

 

The effect of the platinum bead is 10's of milliohms (.001 ohms). So the effect on total series resistance is no effect, since the plug wire resistance
is K ohms (1000 ohms).