Spark Plug Question

[kylereece22]

Hey all. I would like to pick your knowledgeable brains regarding spark plugs for our cars. I intend to purchase a set of six Motorcraft Platinum plugs on ebay. The part number is SP493. Are these the best plugs to get and do I have the correct part number? I have an 89 with the 3.2.

Thanks again!!

 

[zach44102]

I always use Autolite coppers. 1$ plugs, and they last forever.

 

[kylereece22]

Ok thanks Zach I will try and find them up here in Canada. Thanks for the reply!

 

[zach44102]

These motors are not picky with plugs. Just stay away from bosch +4's and stuff

 

[auto.guru]

damn. i put the iridiums in... cost me like $40. sob!
wish i had known this sooner.... i was so picky to make sure i kept it as close to factory settings

 

[mgreen1872]

Copper cheap plugs... copper conducts better, they erode faster and have to be changed more often but copper simply performs better.

http://www.carsdirect.com/car-repai...m-and-platinum-understand-for-top-performance

 

[SHOtimer]

The motorcraft fine-wire plugs work great.

Doug

 

[frosho]

I always use Autolite coppers. 1$ plugs, and they last forever.

These motors are not picky with plugs. Just stay away from bosch +4's and stuff

Copper plugs last forever? Are you high? And since when does the SHO motor not care what plugs are in it?

Go with Motorcraft finewire platinums. Part number SP497 (AGSP32FMF6). They function well and allow the plug wires to form a good seal against the valve covers. Most aftermarket plugs are very slightly longer than the OEM ones. The result is a poor seal that can let water and other debris into the plug wells, eventually causing a misfire.

 

[pejohnson]

^^2 for Motorcraft SP497.

 

[shobote]

I've used 5 different types of plugs in mine since 1990, and they all fit tight, the same as the OEM. The least favorite of all I have tested is the Motorcraft OEM. Splitfires, AC Rapidfire, and E3, what I now run, all perform better for me.

 

[Lorenr]

Copper is a great conductor

That was a good article about spark plug electrodes. I've always wondered why platinum and iridium were used instead of copper. Some of the new and expensive cars require very expensive spark plugs primarily because the car owners don't want to replace them. The only conductor better than copper is silver.

I also suspect:
1. Platinum and iridium plugs are used for emission requirements. The car meets EPA requirements for 50,000 miles without a tune up. Copper plugs would need to be changed to do that.
2. I've heard that while new cars with iridium plugs can go 100,000 miles, replace them at about 60,000. On some cars they can almost weld themselves to the aluminum heads after about 60 K. Put in new plugs with never seize.

:swing:

 

[msteiny]

I went with Denso PK16PR11 aka 3264. I read somewhere that these were as close to a match to the original Motorcraft plugs that came in the SHO. I believe I also read somewhere that Denso made the plugs that Motorcraft put there name on. So that was enough for me. I was alittle leary about going to different brand since I use Autolite for all my rebuilds. However since the ignition system is so much more different than what I am used to, I figured what the ****. No complaints from me about Denso, Just thought I would throw this option out there.

 

[SHORANGERBIRD]

-old style Motorcraft AGSP32PP for me.....

 

[Bob Gervais]

I went with Denso PK16PR11 aka 3264. I read somewhere that these were as close to a match to the original Motorcraft plugs that came in the SHO. I believe I also read somewhere that Denso made the plugs that Motorcraft put there name on. So that was enough for me. I was alittle leary about going to different brand since I use Autolite for all my rebuilds. However since the ignition system is so much more different than what I am used to, I figured what the ****. No complaints from me about Denso, Just thought I would throw this option out there.

Correct on all counts. I've used them before with great results.

-old style Motorcraft AGSP32PP for me.....

I was able to find some of those on ebay last year. Bought a set for the spare parts box, for when my Densos need replacing.

 

[yamahaSHO]

As said above, copper do not last very long. I replace mine about every 10K.