[Z06] Spark Plug Gap

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Nov 3, 2009 | 12:59 PM

Paul 75 L82

Thread Starter

Le Mans Master

Joined: Dec 2000

Posts: 5,245

Likes: 25

From: Blue Ridge Georgia

Spark Plug Gap

I going to install a new set of Iriduum plugs in my 02 Z06. Does someone know the plug gap?

Nov 3, 2009 | 02:18 PM

Melsy

Instructor

Joined: Jul 2002

Posts: 102

Likes: 0

From: Delray Beach FL

Paul;
There was a TSB about a new plug for our cars as well as other GM cars. The Delco iridium plug is pre-gapped. Don't mess with it. The new plug is AC-Delco 41-985. Hope this helps.

Nov 3, 2009 | 02:26 PM

Zo3o6

Racer

Joined: May 2006

Posts: 449

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From: Little Elm Tx

.060 on my `03... should be the same as the `02.

Nov 3, 2009 | 04:22 PM

Paul 75 L82

Thread Starter

Le Mans Master

Joined: Dec 2000

Posts: 5,245

Likes: 25

From: Blue Ridge Georgia

I bought the 41-110. I got that number from the forum. Is that plug pre-gapped?

Nov 3, 2009 | 09:04 PM

Zo3o6

Racer

Joined: May 2006

Posts: 449

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From: Little Elm Tx

Check the gap to make sure, You can buy a gapper at any
Auto part store.... 99 cents...
I put some ngk`s in.... they were gapped at .040
You can gap the plugs when their new, but not after being run.
Ron

Nov 4, 2009 | 12:31 AM

James92

Burning Brakes

Joined: Aug 2006

Posts: 903

Likes: 1

From: Burbank CA

I bought the AC Delco Iridium's 41-985 and I gapped them at .055". Bigger gap, bigger spark. Just did mine 3 weeks ago, I drive the car every day and it runs perfect.

Nov 4, 2009 | 09:25 AM

CSM Z06

Instructor

Joined: Nov 2008

Posts: 178

Likes: 0

From: Erie CO

The AC/Delco service bulletin 03D-J-171 reads "A new spark plug has been released for use in the above vehicles.(Corvette 97-04) The new spark plug has an
Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the
spark plug has also changed. The new spark plug, ACDelco Part Number 41-985 (12571164), is
gapped to 1.01mm (0.040 inches) when the spark plug is made. The spark plug gap is set during
manufacturing and should not be changed to the gap required with the Platinum plug, or damage
to the spark plug may result."

But this isn't really new as the bulletin is dated DEC 12, 2003