Difference in Spark plugs?

[sho4life]

so iridium are useless too? i mean a waste of money if they are more than double platinum..

 

[Bob Gervais]

so iridium are useless too? i mean a waste of money if they are more than double platinum..

Correct. Iridium plugs, so I'm told, were designed to last longer.

 

[nickdodd25]

Has anyone ever heard of Spitfire spark plugs? My car had a bad miss so i did vc gasgets, oil in plug wells, and plugs and wires and that is what i found with origional wires. Jw if anyone has ever heard of that brand cause i never have.

 

[Bob Gervais]

Splitfire? Did they have a forked electrode? They're pretty well known, and an older brand. Another example of trying to reinvent the wheel, and failing.

 

[SHOYAY]

Yea nick Ive heard of spitfire plugs and have used them. Didnt like them at all. Didnt use them on a sho, but I did in my v8 car. Hated them, had some misfires after about 2k miles.

 

[nickdodd25]

Splitfire? Did they have a forked electrode? They're pretty well known, and an older brand. Another example of trying to reinvent the wheel, and failing.

No they look like a normal plug, when i get home this weekend i will get the number off it. kept one cause i have never heard of the brand.

Yea nick Ive heard of spitfire plugs and have used them. Didnt like them at all. Didnt use them on a sho, but I did in my v8 car. Hated them, had some misfires after about 2k miles.

Ya it had really bad low end miss but i think it might have been oil in the plug wells.

 

[gmorrell]

There may be some small performance improvement in switching to a surface gap plug such as the Bosch Pt +4, but you need to be careful with the Bosch Pt center electrode plugs in a waste spark ignition like ours. Each pair of plugs is across (in series) with an ignition coil high voltage winding, and this means that the pair of plugs fires with opposite DC polarities. This causes the two plugs to erode differently - one plug erodes the outside (grounded) electrode more rapidly, the other plug erodes the center electrode more rapidly. Bosch surface gap plugs have a fine wire Pt-alloy center electrode, and as this electrode erodes, it recesses inside the center insulator. As the plug ages and erodes, it can become more difficult to ionize and fire.

Bosch used to have a white paper on their website cautioning about using their Pt electrode surface gap plugs with waste spark ignitions, but a quick search didn't reveal it. They are pretty careful about not recommending plugs for applications in which they haven't tested and qualified them, but that's just typical Germans.

If you want, you can clip back the ground electrode on a normal spark plug to expose more of the flame kernel, this can improve performance if you're looking for every last bit, assuming you'll even notice it, but unshrouded plugs tend to wear out faster, and you most certainly don't want to clip back the ground electrode of a plug with Platinum buttons.

 

[trainguy1989]

i have been running E3 they work great.

My ATX liked those. I have had them for about 10,000 and no problems. My MTX not so much. Weird.

 

[turbo79]

Further follow up:

When I first got my '92, I replaced the plugs. The car had about 145,000 miles on it then. (SHO abuse story - the rear (right) bank had the OEM plugs still in, the front bank some Bosch plugs that I didn't pay attention to because I was going to replace them anyway.)

I installed a set of the Denso PK16PR-L11s. 22,000 miles later, because I had removed the manifold for a porting job and to install BBBs (and for a valve lash adjustment while the manifold was off, since I do not know the history of the car before it came my way) I decided to replace the plugs again - because, well, the manifold is off and it's so much easier when it is off. Looking at those Densos they look just about perfect and, from appearances, could have only 5,000 miles on them. Never has missed a bit under WOT either, clear up to the rev cutoff limit.

Since Denso made the Motorcrafts, and they are the same spec. and double platinum, I'd say that they are a good substitute. $7.15 each at my local Carquest.

 

[jayro]

I have always used the autolite double platinums and had very good luck with them. I have heard of some people having issues with them because they are slightly longer than the oem ones, but it has never happened to me.

 

[turbo79]

I have always used the autolite double platinums and had very good luck with them. I have heard of some people having issues with them because they are slightly longer than the oem ones, but it has never happened to me.

I imagine that the Autolite PP plugs perform just fine; in my case, I need a tight OEM plug well seal, because I live in a rainy climate, and also drive at times on dusty roads. So the Densos are necessary for me for that fact alone.

 

[xshoel93x]

when i did my 60k a month or so ago i went with motorcraft double plat plugs and denso plug wires. some mustang guy was complaining that his plug wies were 80bucks. i showed him mine were double that n he stfu haha

 

[sho4life]

I just checked ebay and all that came up for the motorcraft were a $1 suppressor plug? what is that? looks like no one carries denso or motorcrafy except for dealer. the autolites are $17.44 after rebate and the densos are $57 and the motorcrafts are $51.06

I never had the autolites before and i hope that not sealingseal 100% isnt that big of a deal. I dont really have the extra money just for that.

 

[Bob Gervais]

I bought some AGSP32PP's on Ebay last week. Search that number and you should be able to find them.

 

[frosho]

I bought my Motorcrafts at a local parts store. I think it was Advance.

 

[Bob Gervais]

I bought my Motorcrafts at a local parts store. I think it was Advance.

Ditto. I've gotten Densos at Advance also.

 

[sho4life]

the one store i have to travel 100 miles to, ill have to check it out tomorrow.

 

[sho4life]

according to advance auto motorcraft and autolite are both 2.985 in length. Someone said the autolite are longer. whose is right?

 

[luigisho]

Try Rock Auto. They should offer Denso, Motorcraft and AutoLite.

 

[frosho]

according to advance auto motorcraft and autolite are both 2.985 in length.

According to my eyeballs, they are not equal.