Spark plug gap
 

I've searched the forums and cant seem to find any infor on what our stock AC Delco spark plugs are gapped at for the LT1.

I'm curious because my tuner is asking me to gap mine at 32 thou.
I have Rotofab dry filter intake, ported stock TB, and 1 7/8 headers with high flow cats. 93 octane.

Is there any downside to having the gap so small, at 32 thou without being boosted?

I'm asking because I want to buy some pre-gapped iridium plugs, to avoid messing up the iridium tips.

Thanks!

The manual for my '21 has gap info.. though I'll leave the "what's best" for those with more knowledge than me.



For the 6.2L: 0.95–1.10 mm (0.037–0.043 in)

thanks!
curious why im advised .032 as NA with bolt ons
not saying its wrong, i just dont see a lot of info on it

I have only ever heard of tightening the gap when running boost, not while on NA.

But maybe because of the LT1 being direct injection? Just a guess.

I think .032 to .034 are good numbers for NA. Thats close to what I run on my C7 NA Vette. I ran .025 on my Maggie 2650 Camaro.

Just picked up some new AC Delco 41-114's.
They are pre-gapped at .040

Any other input before I just gap them at .032 or .035 and throw them in?

Seems like a small gap but I guess there's no real downside to that..

i gap the ngk LTR5IX-11 @ 40. no issues, 20k miles.

A wider gap hypothetically creates a little hotter spark, a closer gap creates a small amount of spark advance.

Don't the plugs come pre gapped.

Run as wide a gap as you can get away with. It'll tell you when it's too wide. Easy enough to get to the plugs on this car. I'd start at .040 and see how it responds.

Just curious...if your tuner tells you something like what to gap your plugs at and you feel the need to go out and ask the forum, doesn't that mean you don't trust your tuner? And if you don't trust your tuner, why stick with him?

I am all for research and double checking and maybe that's all you're doing. Not trying to start an argument or anything.

Not at all.

I am simply asking reasoning. Trying to learn more. I am brand new to the 6th gen / LT1 engine.

I fully trust my tuner. Just curious the reasoning for the change. Gaining knowledge.

Makes sense. I am new to the tuning game...or I will be once I get into it in the near future and want to ask the right questions as I go along so I hope to learn from all of you that have gone before me.

ProdigalLunatic posted gap for the LT1 above. FWIW, LT4 Performance supplement manual says 0.029-0.034 inch, so yeah a little smaller than NA.