Spark plugs (gap size)

**Justin23454** · 12-14-2007, 06:08 AM

If I dont have the peice to check the gap size, what could I just to check it, I just bought the AC Delco Iridium yesterday and wanna put them in SAt. when I do my headers, anyone know what else I can use to make sure they have the right gap?

**rbob93** · 12-14-2007, 08:36 AM

Simple.....a wire type plug gauge.....borrow one if you must.
You paid $6 each for plugs.....you want the most out of them don't you?

**Justin23454** · 12-14-2007, 09:13 AM

ya, what size gap should I have in it?

**rbob93** · 12-14-2007, 09:53 AM

I gap mine @.055 but I'm pretty much stock

You'll need a tune for the headers.....you might want to ask your tuner for his recommendation

**Firebirdjones** · 12-14-2007, 10:02 AM

I prefer to usea regular feeler gauge,,,can pick them up at any parts store,,,they are cheap.

I believe stock gap is .050 but alot of people tighten that up a bit. I know I closed mine some,,,but can't remember how much off the top of my head.
But like Bob said,,,if you use a local tuner,,,ask them what they like to see and adjust accordingly.

**ranmansbaby** · 12-15-2007, 07:32 AM

.055 is ok but you cars plug are suppose to be gapped @ .060 and yes you can use a feeler gage but it's not going to be acurate because even on a spark plug feeler gage you only have in thousandths .025-.045

**ranmansbaby** · 12-15-2007, 07:32 AM

i work at Napa and i see this alot

**rbob93** · 12-15-2007, 08:59 AM

Originally Posted by ranmansbaby

.055 is ok but you cars plug are suppose to be gapped @ .060 and yes you can use a feeler gage but it's not going to be acurate because even on a spark plug feeler gage you only have in thousandths .025-.045

What the hell are you talking about???

**Firebirdjones** · 12-16-2007, 05:30 AM

I got lost on that post too,,,,,lol,,,,,I have used a feeler gauge for many years,,,works great,,,,with increments of .001 you can make them any size you want.

But most tuners will tell you to tighten up that stock gap a little bit. Some go as tight as .035. It's been proven many many years ago that a wider gap does nothing for HP,,,it only makes the coils work harder.

Also on a nitrous car,,,,blower car etc...with alot of cylinder pressure it's best to tighten the gap,,,,as high cylinder pressure will tend to blow out the flame on high cylinder pressure applications.

If you modify the car at all,,,,with bolt ons,,,,,camshaft, heads,,etc....you can experiment with gap size,,,or better yet,,,,ask some local tuners in your area that dyno,,,build,,,and tune LS1's they may give you a better idea what they see and like to use.