Originally Posted by Snagglefoot
Sorry, can't agree with any this. There is plenty of room in the thread profile to hold the anti-seize. I've used aluminum anti-seize for years in aluminum heads without problems. Everyone is entitled to an opinion.
Note "second and third thread" in this description:
https://www.aircraftspruce.com/catalog/eppages/antiseize.php
Also-
https://www.underhoodservice.com/tech-tip-a-day-in-the-life-of-a-contaminated-o2-sensor/
"If the new sensor does not have anti-seize pre-applied, be sure to apply some to the threads prior to installing the sensor. Do not put excessive amounts of anti-seize onto the threads. Getting anti-seize compound on the sensing area will contaminate it."
Likewise, extruding excessive anti-seize from the spark plugs will eventually work its way downstream to the lambda sensors.
I won't back down on this one, IMHO that's a grossly excessive amount of anti-seize.... multiplied by the number of plugs in that bank. But that's just my opinion.
Originally Posted by Kestas
Originally Posted by HangFire
In addition, Honda's have aluminum heads, and that appears to be aluminum anti-seize. A dissimilar metal to both sides should be used in all cases. For uncoated steel plugs in Honda's Aluminum heads I would use Bronze anti-seize, in a vanishingly small quantity.
I don't follow your logic. Why should a dissimilar metal be used?
It's not my logic, it is industry practice.
While all anti-seizes are used to prevent galling, there are different chemical purposes and strategies used by different anti-seize types and applications. Prevent rust. Prevent dissimilar metal galvanic corrosion. Prevent similar metal cold welding. Prevent water intrusion.
There is a lot to the choice. Copper should be avoided where stainless steel is involved, but is great for other applications, up to certain temperatures. Nickel for really high temp (which is why the NGK's are nickel plated). Aluminum for many steel on steel, steel on iron applications. There are also metal-free choices.
There are exceptions. In Marine applications you might use one with Zinc content for the sacrificial ions, even though there may be a Zinc plated connector (screwed into Aluminum) involved.
This has been well-discussed on BITOG before. There seems to be no conformity of opinion. For that reason, I'll not debate any further. You can look into it for yourself.
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1942399/1
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/2945586/1
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1828791/1
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4504652/1
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/2062494/Re:_What_kind_of_antiseize_for
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2904468