Tallimeca, where was the purplish tint?

LTNBOLT, I'll take your word for it, but I don't think my plugs look like yours. I'm assuming yours were taken out with more miles than mine (4755), but notice how the white collars on mine are already stained with carbon? Mine remind me of those old commercials where they show someone dipping their fake set of coffee/smoke-stained dentures into a cleaning solution that made them sparkling white. Yours look like they've already been soaking in the Polident for a few hours.

 

on where the white of the insulator on the part inside the combustion chamber.... Don's Bolt seem to think the previous owner used octane booster. I think it's possible.

 

How do they look? Like you should have left them in.

 

well if you put octane booster in that will do it

 

SilverBolt, that seems to be the concensus. But I'm glad I swapped them since everyone here seems to think the factory plugs make better paperweights and the dealer wanted to remove the cheapest variable in my rough idle problem first. The TR6's are definitely running better. I'm surprised I can tell a slight difference with throttle response. Not sure if it has to do with the different temp rating, or the plug design itself. But something better is happening under the hood because it feels different, almost like the engine is more eager to rev and smoother doing so. Hard to describe, but at least it's not running worse...

 

tallimeca, I used to work up in Boston , and I have found alot of the time the purple tint is form the additives in the Gas up there. I had also seen the problem on my Mustang when I worked in Philly back in 93.

 

Big6: I personally think Motorcraft plugs get a bad rap here. I've used them for almost 30 years (ever since Ford swithed from Autolite to Mototrcraft as their stock plug in 1973) and have had very good results with them. I will admit my experience with superchargered applications is limited though. With mods you're probably better off taking the advice of someone like Sal, JDM or JL.

 

They look a lot better than mine. I pulled my TR-6's after 14,000 miles. They were showing sign of serious erosion arould the center and ground electrodes. Looks like they were right on the edge with the tuneup I have.

I swapped in BR7EF's for the races this weekend, and I'll keep you posted on how they run on the street. I can already feel slight misfire at very light loads.

 

Ben,

They probably have less miles on them than yours. I took them out not long after I got the truck. The stock plug is the only one out of the many I have ran that had a reddish purple look on the center electrode. I have never ran octane boost or nitrous. If you run octane booster the whole end of the plug usually looks dark purplish red. That stock plug had been setting around for over a year when I put it together with the others to take the pic.

I have changed plugs 9 or 10 times testing different plugs. That is just in my truck not including a couple of friends that I helped out. The bottom line is if you are running a chip and other mods then you need the keep an eye on the plugs. Check #5 a couple of times after making any changes to your setup. If you are running pulleys then I would think about changing them every 10,000 miles for good measure. Listen closely for even the slightest amount of rattle or pinging at the top of drive on into O/D. This is deadly to your plugs and your engine for that matter.

 

Ben,

Here's a better comparison. It looks like yours are definitely richer. I thought mine looked kinda fat but your plugs look even worse.

 

Good advise LTNBOLT. I don't have any mods, but just the same I think I should keep an eye on my plugs anyway.

Jay, what kind of mods did you have on your L when you pulled the plugs?

SilverBolt, I don't have any scientific proof to discredit the stock Motorcraft plugs either. I know a number of L owners are happy with them, but my dealer didn't want to start replacing expensive warehouse-order items without going through the cheap, easy stuff first. My tech happens to have an L too and strongly suggested I try the NGKs as he likes his set a lot. After a number of folks suggested the same I figured "why not" and let him swap em out. I'm glad he did. First, because the L does seem to run a little better. And two, now my dealer can get serious and get to the bottom of my rough idle since most of the obvious items have been checked/replaced now. I'll continue to post their findings and any other updates to my problem. Thanks everyone for posting - I appreciate each contributor's perspective and hope I can return the favor and pass on some of my knowledge whenever I can. If I can't, I'll at least entertain the forum with more Photoshop humor...