------Questioning spark plug situation-----

[lasercobra]

The car has been smoking under boost through first gear. All the rest are clear so I decided to pull the plugs and see what they looked like. I only got through two on the driver side before questions started popping in my head.

1. They are Autolite 764 and I read that these are around the stock heat range. That's not the right choice for a blown car, is it?

2. The two I looked at were fine in terms of color (nice even light black color, no oil..) but the porcelain around the electrode appeared to have fine cracks in it. Would you say that's normal? I've never noticed it in any of my other Mustangs and the first two I pulled looked the exact same.

3. I checked the gap on one and it was .35. That's a little two wide for stock ignition...?

I've seen enough to know I want new plugs in this car. What would you recommend and what gap? Money is an issue for no $7 plugs please. ;-)

 

[George Wax]

I have had excellent luck with Denso's IT 22 gapped at .38 had them on my blown Cobra for about 30,000 mile's with no issue's and a rich tune. I am now running Autolite AR 103's gapped at .35 with no issue's copper plug's. Either of these two choices would be great for your car. I run about 10 pound's of boost.

 

[kezell]

You can also try running a closer gap on the plugs to make sure they are firing. But if you have any cracks in the ceramics I would change them.

 

[Quadcammer]

you could try a ngk tr6 or motorcraft awsfa-22c.

if you aren't getting spark blowout, the gap is fine.

what color is the smoke?

 

[lasercobra]

At first the smoke was clearly black, more fuel then anything but now it appears to be getting more white/grey. I'm not losing coolant and my oil consistancy is fine. I want to change the plugs today just to be cautious on their condition. A friend lost part of a plug's electrode in one of his cylinders and it ate the wall up. He started using oil and smoking real bad under acceleration.

So I should stick with .35, huh? Sometimes I get a stutter/hesitation when switching gears under boost at high rpm. I'm wondering if I'm getting a little blowout then?

I'll check those other plug suggestions.