?best spark plug gap for long life iridium plugs

[mechtech2]

Not only check the gap, but the internal resistance from the connector to the tip. Each one.
Don't worry about a couple of thou gap difference.
A plug may have been dropped or banged, or a mfg mistake may have been made.
Every now and then, we get a bad new plug. Maybe once a year.
Have one comeback or bad test drive because of a bad new plug, and you'll always double check them when new.

 

[PandaBear]

What happens to a plug that is banged or dropped? does it disconnect internally?

 

[NortheastPest]

Just out of curiosity, what is the reason you are against anti-seize on spark plugs. I have heard a few people on this board specifically mention that they DO NOT use anti seize while installing plugs. I was just wondering if there is a technical reason or is it just a preference. Thanks.

Lou

 

[[RT] ProjUltraZ]

when i changed mine, i carefully checked a few w/ a leaf style gauge and they were all 0.040 so i put em all in and called it a day. i also used a small bit of copper anti-seize which i hear is good for spark plugs in alum heads. i think the only danger is they will back out if you use too much or not enough torque

 

[rmattingley]

go ahead and gap them, then in a few months when the tip falls off you can come back and [censored] about how cheap these plugs are. Just go buy some denso or nkg's and put them in. Drive 100,000 miles and repeat. If you think that .01 is going to make that much difference in that car you are crazy.

 

[panthermike]

Originally Posted By: rmattingley
go ahead and gap them, then in a few months when the tip falls off you can come back and [censored] about how cheap these plugs are. Just go buy some denso or nkg's and put them in. Drive 100,000 miles and repeat. If you think that .01 is going to make that much difference in that car you are crazy.


I guess you missed the other posts..... .01 is a negligable difference and I would not gap the plugs in that case, never said that I would. I contacted NGK and they said the plugs can be gapped, but very carefully.

And I agree, put them in and drive for 100K miles and don't worry.

 

[sprintman]

NGK have anti sieze coating from factory I believe? NGK quality control is exceptional as well, never had a bad plug which is more than I can say for other brands.

 

[mechtech2]

A drop can break a plug internally as well as externally. You may not see it, so check them. It is not common. Do you want your mechanic NOT to check for this? Would you stop him?
Also mishandling can change any pre set gap.

And who says the gap is only .001" off? It could be loose or tight by ANY amount.
The tips do not easily come off. What the heck do you think is happening in the combustion chamber??

I believe this myth is because of waste spark ignitions, where the factories used single tipped plat plugs on different holes, to save money. When people remove them, they see only one tip, and assume it came off.
Some plugs fire +to-, and some-to+.