Ordered a set of Denso iridium plugs for my 2001 S2000. Received a set of IK22. When I look at the Denso site they recommend IK22G plugs but the heat range is the same - everything is the same except that the electrode is 0.4mm vs 0.8mm on the IK22G.

Are these ok if gapped correctly, what is recommended gap - no turbo or supercharger on car.

Thoughts please

 

You'll be fine with either. The central electrode on the "old" IK was very delicate and prone to breaking if gapping was done in a sloppy manner. I think Denso made the electrode thicker to give it more strength to minimize accidental damage.
Gap it the same as for OEM plugs (about 0.040" to 0.044").

 

Electrode is 0.4 mm - u-grooved. Is this the older version then and just be careful?

Heat range is correct as are dimensions.

 

I think the "groved" part is in the side/top electrode. Not to worry, just handle it carefully when gapping. Don't touch the middle electrode with too much force.

 

FYI

I was told that you should not gap iridium plug. In gapping them you remove the iridium coating. This is why they pack them with the electrode protected. Also it was not one person that said this, it was a few.

Your thoughts??

 

It's got to be more than just a "coating" of Iridium to withstand the extreme heat inside a combustion chamber.
If you're talking about that little cylinder that is placed around the threaded part, that's just to protect it during shipping. Afterall, Iridium plugs are supposed to have the longer lifespan of any present day plug.
Also, for F.I. use, they must be re-gapped as the gap they come with is too big. As I said, care must be taken when measuring the gap then even more care must be taken to change the gap. The standard type of gapping equipment out there cannot be used as they can apply pressure onto the central electrode. I've used one of these (flat disc type) for closing the gap but I use strong needle nosed pliars to open the gap as neeeded.
We can't always assume that the gap is correct for each application. Common sense must prevail and all plugs should at least be measured before putting them into an engine.

 

I agree that they have to be checked and it is obvious that you have to be very careful on the electrode. In my 35 years of playing with cars I have never seen one so small,

 

Smallest out there.

 

That means no banging them upside down on the ground to close the gap

 

I had mine checked last night and they are all gapped to .032 already. I wonder if they were re-gapped by the person I bought them from. They said brand new, but didnt mention they had been gapped?!

Ryan