Focus Fanatics Forum banner

1 - 15 of 15 Posts

·
Late for Dinner
Joined
·
15,332 Posts
Discussion Starter #1
ok, i ran across this question on a different site ive been pondering...
on fi everyone suggests the AZFS-22C-f4 coppers in a boosted svt
the stock svt plug is a AYFS-092-FECF4 which is a platinum.
now a 092 is actually 2 steps colder than a 22, why are we being told to use a hotter plug?
a stock zetec uses a AZFS-32-FEF4. the 22 would be 1 step colder in this case.
Have people just been using the wrong plug for a reference on svt's with fi(stock zetec)? or is there another reason weve been going 2 steps higher?
sorry but ive gotten very inquisitive as to why...

i can post an actual ford plug chart if anyone needs.


and before anyone with an svt says we do use the 32's, check your suplement in your glove box for the svt.
 

·
Registered
Joined
·
9,084 Posts
Interesting. I was always under the impression the AZFS22C was 1 step colder?
 

·
Late for Dinner
Joined
·
15,332 Posts
Discussion Starter #3
it is for a regular zetec. but 2 steps warmer than a stock svt plug.
been discussing it with friends, but cant figure out anything than someones using the wrong plug for a reference...
only reasoning weve come up with is copper has a way lower melting point than platinum and would burn to ash if something were to go wrong instead of dropping into the cylinder
 

·
FF Affiliate
Joined
·
31,087 Posts
Platnum isnt good for performance altho the chart shows it as colder it truely runs hotter if you look at it with it charted correctly with a copper chart then a platnum chart the 22c is close to the same heat range as the stock platnum plug

Here you said it yours self "copper has a way lower melting point than platinum "

I work close with autolite one of the dyno used back when they changed to there AR series were from my dyno, I will try to find the copper vs Plat chart

The heat range of the plug can be checked by the eye , if you look at the plug part that goes in the cyl and look at how long the porcelain is then look at another plug the colder plug will have a shorter amount of prcelain around the electrode

The whole idea behind platnum plugs are they will run 100,000.000 miles because they run hotter and keep the oil and other particals burned off where copper at the same heat range in most cases will only be good for about 25,000 to 35,000 miles

And the Plat cost 3 times as much

Tom
 

·
Registered
Joined
·
11,906 Posts
Not to forget, the thicker the electrode the fatter the spark.
 

·
Registered
Joined
·
11,906 Posts
But it sounds plausible [:D]

But seriously.. havent you ever put an electric charge through 2 different sized wired and noticed the size of the spark woud change????

I had a very mis-spent youth.
 

·
Registered
Joined
·
218 Posts
LOL...yeah, it does sound plausible, it just isn't the way it works.

The peak voltage is actually more dependent on the resistance that the coil "sees" in the cylinder. The higher the resistance, the higher the voltage. The wider the gap, higher the cylinder pressure, etc., the higher the voltage.

The trick is that at a certain point, the current looks for an easier path to ground. That can be through the side of the wire, boot or through the insulator of the plug...or even internally between the winding of the coil.

Having nice sharp edges on the electrodes helps get the spark started. Aside from that, the goal is to have as small an electrode as possible to expose the mixture to the spark to the greatest extent possible.
 

·
FF Affiliate
Joined
·
31,087 Posts
Exactly , thats why i went back to Autolites after they started cutting back the wire with the "AR" series plugs and from my dyno testing they work

It old school and i dont know why all the plug makers got away from doing it

Tom
 

·
Registered
Joined
·
305 Posts
So which plugs do you recommend for a zetec(Zx3) running about 10psi? Thanks.
 

·
Late for Dinner
Joined
·
15,332 Posts
Discussion Starter #11
thanks tom. and if you can find the charts i for one would apreciate seeing them.
as i said, i found this on another forum and it just kinda peaked my interest. they labeled it spark plug misinformation and are trying to tell people to use the plats because theyre colder.
i for one have always been told in any type of boosted or seriously built motor always use copper
 

·
Registered
Joined
·
305 Posts
1turbofocus said:
Its not like we have a lot of choises , I would use the AZFS22C

Tom
Thanks...and what would you gap them at? That is a motorcraft number right?
 

·
FF Affiliate
Joined
·
31,087 Posts
You want the most gap ypu can run with out the spark being blown out , I would start at about .045 and see what happens if you get a upper RPM misfire close the gap slightly if you dont see if you can go to .050

Tom
 

·
Late for Dinner
Joined
·
15,332 Posts
Discussion Starter #15
whayong said:
I don't recall reading it labeled "misinformation" or anyone telling anyone to use different plugs. The way I read it is that someone stumbled on some information and they're having a discussion about it. Just like there is one here.

the other thread is labeled"spark plug heat range misinformation", which has turned into people telling others to run plats because they are 2 steps colder than coppers.
that and as usual it didnt stay on track because they are now talking about cobra's and no info as to why on the plugs has been produced.
People here actually try to discuss and put info into a thread so they and others can learn. thats what i and others love about this place.

now, to get this thread back on track...
 
1 - 15 of 15 Posts
Top