Spark plugs Need a quick answer plz

**Justin23454** · 12-15-2007, 09:39 AM

I bought ac delco iridium plugs and they are gapped .40 is this to small should I re gap to .55? Im in the middle of doing my header change so need a quick answer if anyone can give it

**rbob93** · 12-15-2007, 10:09 AM

yes

**sroach20** · 12-15-2007, 02:42 PM

you are not supposed to gap the iridiums, you will screw them up.

**rbob93** · 12-15-2007, 03:36 PM

That's because the electrode is so small it's easy to bend it & screw up the plug

**Justin23454** · 12-15-2007, 07:20 PM

so yes or no to gapping? Leave it at .40?

**sunsetorangess** · 12-15-2007, 08:02 PM

Just leave it at .040 If you decide to regap, just becareful when doing so.
Stock is .060, pretty sure anyhow, its been a while
I wouldnt even worry about regaping, im running .035 with no issues.
J

**chuckie669** · 12-15-2007, 08:21 PM

Yeah, stock gap is .060. I believe I did mine right at .055, and from what I had heard you don't want them gapped any less than .040. Not sure about Gapping the iridiums, so good luck!

**sroach20** · 12-16-2007, 04:27 AM

gm changed it to what i thought was .045 on the iridiums.

**rbob93** · 12-16-2007, 08:31 AM

ACDelco Professional Iridium Spark Plugs

ACDelco Iridium Spark Plugs are the latest evolution in high-performance plugs. The natural properties of iridium, with a melting point approximately 700 degrees Celsius higher than platinum, helps enable the plug to burn fuel more efficiently and to deliver better performance. As a result, the iridium plugs have a minimum service life of 100,000 miles.*
Since iridium is one of the densest materials found on earth, the iridium-tipped center electrode is 50 percent the size of a platinum electrode and 20 percent the size of a conventional nickel electrode.
The secondary microdischarge of the center electrode burns off carbon deposits as they form for superior antifouling performance that, along with the tapered cut-ground electrode, offers enhanced flame spread during combustion.
The specially designed electrodes increase the electric field strength at the gap, reducing the voltage required for sparking to begin, for improved cold starting and quicker acceleration.
The application coverage of ACDelco Iridium Spark Plugs continues to grow, with the plugs backed by a 100,000-mile limited warranty.
*Service life varies with individual driving conditions.

Taken from AC Delco ad....might explain why the gap is alot smaller

My apologies for any misinformation earlier

**28Marcos** · 12-18-2007, 10:45 AM

damit i wish i would have read this yesterday!!! i was wondering why it all my ngk iridiums were gapped at .45 lol, i put them to 60! oh well i'll put them back when i get bored, only took me 45 mins to do them all

**thearborbarber** · 12-18-2007, 01:04 PM

Here is a pic of the TSB for the Iriium plugs

**35thAnniZ28** · 12-18-2007, 03:42 PM

Originally Posted by 28Marcos

damit i wish i would have read this yesterday!!! i was wondering why it all my ngk iridiums were gapped at .45 lol, i put them to 60! oh well i'll put them back when i get bored, only took me 45 mins to do them all

dood wtf...even 5 n 7?

**28Marcos** · 12-19-2007, 08:25 PM

yea, my trick is to use that anti sieze stuff on the threads, then use the spark plug socket that has a bolt pattern on the end, use the correct socket on that or wrench, easy. of course after i remove the egr and coil packs, its just having the right tools, like the 10mm rachet wrench for the coil pack saves a lot of time