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interesting spark plug wear

D

DocStruthers

Veteran CEG'er
Joined
Dec 11, 2008
Messages
864
check out the photos.

the ones with NO electrodes(due to wear)
were in the front bank.

strange huh?

What can everyone tell me about my engine?

I would say it is running very hot and rich.

but since i changed to NGK G Platinums it is MUCH better.

All6Top.jpg

All6.jpg

BADtip.jpg

BurntEnd.jpg

GoodBadComparison.jpg
 
Yeah, those don't perform well in our cars. Good thing you changed them.
 
The difference in wear between the front and rear banks is because of the firing polarity difference created by the waste-spark ignition system. Each of the three ignition coils fires two plugs, one on each end of the high voltage secondary winding. One plug fires the center electrode at positive polarity, the other fires the center electrode at negative polarity, which causes metal to erode and transfer in different directions between the center and ground electrodes of the plug. Those are some of the best photographs I've seen of this phenomena; the plugs with recessed center electrodes have a lot of the center's Platinum/Iridium alloy spattered on the ground electrodes, while the other three plugs are pretty clean.

If you do some research, you'll discover that Bosch does not recommend using their Platinum +4 plugs with waste spark ignition systems. They also don't recommend using them on boosted engines or engines using nitrous oxide.

When Ford delivered the first Taurus SHO's and Thunderbird Super Coupes with waste spark ignitions (low data rate DIS), the OEM spark plugs were supplied selectively tipped with Platinum. Three plugs were tipped on the center electrode, the other three had a Pt button on the ground electrode. You couldn't buy these plugs from Ford or in the aftermarket, everything supplied in the aftermarket was designated "PP". meaning both electrodes were Platinum tipped.
 
holla

holla

if that were true the wear would be on all 6 plugs?

Unless for some reason one bank was changed and one wasn't?

I thought these photos were GREAT!?

I hate my camera but it takes great macro and super macro shots.

can u see where the spark started cutting into the metal on the one with the retracted electrode.

I thought at least someone would find these photos interesting.
 
Bosch plugs always suck in Fords.. Ive run them in my 89 Tempo and the Mystique and they make the engine run hotter and not near as efficient.
 
DocStruthers said:
if that were true the wear would be on all 6 plugs?
Click to expand...

No, the wear is different because pairs of plugs on the same coil fire at different polarity, and this changes how the electrode metals erode and transfer. The center electrode is always hotter than the outside electrodes, and this causes it to emit electrons. If the current flow carries electrons away from the center electrode, then metal leaves the center electrode as Platinum ions, the electrode erodes away and recesses into the insulator. If the current is flowing in the opposite direction, the erosion still happens, but not as rapidly, so that electrode doesn't recess as rapidly as the other.

Read these two, as they're spot-on about waste spark ignition systems, see if they help.

http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/DIS_EDIS.htm

http://www.miracerros.com/mustang/sparkplugs.htm

p.s. I did like your pictures, as they well illustrate the erosion issues with waste spark ignition systems, and they really point out how ill-suited the Bosch Platinum plugs are for this application. Seeing splattered Platinum all over the ground electrodes of three of those plugs just gives me a woody. :laugh:
 
All of the gimmick plugs (splitfire, +2 +4) suck. Electricity follows the path of least resistance. It can't jump to all of those at the same time. All you are doing there is moving the spark kernal around in the cylinder.
 
i know i would never buy any of those plugs. it's just a selling point to unknowing and vulnerable parts store customers.
I heard of a champion dual spark breaking and the tip DESTROYED the engine of the Chevy truck it was in. But who cares. Chevy!
 
Its a solara. who cares.
AND it's the wifes. who cares.

haha spend money on your car.
buy the good parts for your car.
heelllloooo :cool:
 
Personally I'd go back to the autolite plats on your next change but the bosch plats are a more standard design so it shouldnt hurt anything.
 
Bikers have known about the reverse polarity of wasted spark since the '60s. One plug wears the outside wire electrode and the other wears the center, since it fires backwards. The side that spark jumps away FROM will always be the heavy wear point.
 
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