Ok...what year car do you have, what engine, ect...but....what do you gap your plugs at; and why?

Meaning; If you have excellent spark plug wires, a hotter coil, along with premium plugs...do you gap stock...or... do you gap a little wider knowing the coil,  and wires will throw more volts, and the premium plug can produce a better spark.

I have Magnacore wires, a MSD coi,l and new E3 plugs...but I want to gap the plugs accordingly.

1996 LT1-- 10:8.1 compression---bored, stroked, decked, milled heads, ported, w/splayed 4-bolt main....3/4 cam, roller rockers, and a few more goodies...

I seen dyno results using E3 plugs...I wanna know some variances.



Thanks,
Jim



BTW--the "3/4 cam" deal is an oldie...just had to throw it in!
Becuase I have a full cam...no, a race cam, a street cam...an RV CAM!!!!!!

I don't believe that the gap really makes a difference unless it is too great to make the spark. .035-.050 should work with any ignition system. And as an electrician, a 10k spark will ignite the fuel just as well as a 40k spark. I worry more about carbon tracking and shorts from the coil to ground...Phil

My belief is that you should run what the factory recommends. If the engine has been modified with heads/cam etc., then you might be able to modify the plug gap some, but not a lot. For most aftermarket electronic ignitions, I'd suggest finding out what the manufacturer recommends. Some of this depends on the physical limitations of the plug itself...not all will allow a wide gap without distorting the side electrode, and basically rendering the plug useless in high rpm situations. Firing a spark across a particular gap at idle is a LOT different than firing that same plug at higher rpms, regardless of the available spark energy. You have air/fuel turbulence, and timing issues to deal with, as well as combustion temps.
GM spends a ton of engineering time to determine what works, as do the aftermarket suppliers. Their specs are what works...go with that.  

I'm going to resurrect this old thread because I'm about to re-gap my plugs top 0.060 per MSD as I'm running their coil, wires and MSD-6 programmable.  I'm going to disagree with the previous post a little to the extent that GM engineers set things up for the widest possible operating range to create the least number of operating problem , often at cross purposes to  where performance can be had. A good example is the ignition timing map. The 96 timing map above 3000 RPM is way off best power, probably to deal with the very worst gas available. Getting back to the gap, MSD displays at the track will show you air gaps half an inch wide and the ignition jumping that gap and firing just fine! I also know that blown nitro are run at half that of a regular gas engine gap but that's because of the outrageous amounts of fuel in the chamber and nitro increases the resistance across the gap. More gap means hotter spark, that's basic physics. The wider the gap the more energy it takes to jump the gap and the higher potential means the more likely the mixture is to be ignited. Interestingly, a spark plug is not a guarantee it will fire. Research engine technology explains it's statistical to some extent and a spark plug increases the odds in a particular location.