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Spark plug gap?

Posted: May 8th, 2009, 6:51 pm
by SilverXJ
Should the plug gap be any different from stock for a stroker?

Re: Spark plug gap?

Posted: May 8th, 2009, 7:47 pm
by shockcocker04
i used stock, but im curious as well

Re: Spark plug gap?

Posted: May 9th, 2009, 5:04 pm
by Alex22
I'd leave it alone unless you have a high voltage coil or better than stock ignition system.

Re: Spark plug gap?

Posted: May 9th, 2009, 6:03 pm
by eastin82
say you had the better than stock would i open it up or close it

Re: Spark plug gap?

Posted: May 9th, 2009, 7:16 pm
by SilverXJ
From what I read with increased compression you should close the gap up a bit.

Re: Spark plug gap?

Posted: May 12th, 2009, 3:04 pm
by ajmorell
With increased voltage you open up the gap.

Re: Spark plug gap?

Posted: May 22nd, 2009, 4:30 am
by the_wrench116
i've got bosch platinum+2 in mine with a msd al6 and wires and the stock coil. i have mine gaped at .197 from ground to ground and centered over the tip of the plug so in a conventional plug .098ish starts and runs great.

Re: Spark plug gap?

Posted: January 4th, 2020, 5:26 am
by darkcorp
Hi guys!

My story.
I have viper coil mod on my 4.6 stroker (CR 9.5).
While break-in I used NGK ZFR5N (7917) spark plugs gapped to 0.035" (0.9mm). Sometimes I had missfire codes on random cylinders.
Changed 4 of them by a set of 4 spare Bosch platinum fr9hp gapped to 0.035" (0.9mm). And I've got missfire codes on all Bosch spark plugs!
Then changed them back to NGKs but gapped to 0.043" (1.1mm). Very noticeable difference in power! Engine works much smoother and responsible!

So what safest spark plug gap is possible to use on a stroker with viper coil mod? I want to try colder spark plugs with bigger gap. Maybe 0.065" or so.