How to change spark plugs

**Sarge** · 04-13-2008, 08:16 AM

Basic stuff here for those who are starting out in the hobby. Before I get all the 4 banger ricer jokes I had already done one side and only had one side left...so blow me in advance. And you guys who PM me...feel free to PM me....but dont be afraid to ask...I had 2 PM's in the past week asking about basic spark plug changeout info...so I'll post this with some pics and hope it helps the new folks starting out twisting a wrench. I will not get into what type of plug nor the gap wars.....for the record I use NGK55's and gap them at 0.40. Why? Cuz I change my plugs every spring and that is what I do. The gap came from testing and testing. So here we go.....
Guys....get some light on the subject....I see folks working in the dark all the time....you gotta see what in the hell you are doing firstly....

The Dielectric Grease and the Anti Sieze is some potent stuff....so wear some simple cheap latex gloves as we are going to be handling this stuff...

Dielctiric grease and anti-seize DO NOT conduct electric charge....so keep that stuff off the firing ends of your plug.....I use them to A) keep the plug from seizing in the hole. The anti seize will allow you to easily get your plug out next change versus having to fight a broken off plug in your cylinder head. Do it! B) The dielectric grease provides a seal to keep moisture and shit out....makes a good seal around both ends of your plug wire. Dont get that shit on anything that needs to conduct a charge!
Lay your stuff out....again...blow me with your 4 cylinder remarks

Gap your plugs.....I use a round gap tool or a wire gap tool.....to close the gap I just press them down against a hard surface.....then use the gap tool to adjust to the desired gap....

Check your gap and then check it again.....

I smear dielectric grease all over the porcelean....

Then I smear the anit sieze on the threads...

I use a extension and the socket loaded with the new plug to start it and hand tighten it....

Then I get the ratchet and tighten it to about 20lbs or about a 1/8th of another turn after hand tightening. DO NOT OVER TIGHTEN!...
I smear some dielectric grease on the coil side of the plug wire connection to seal it up....

Fairly straightforward.....do not get in a hurry...take your time and do it right.

**stevenm357** · 04-13-2008, 09:38 PM

Nice Write up. you have a bad assed GTO!

Do you believe in indexing the spark plugs, I've heard of some doing that claiming better HP #'s etc.

Again good write up.

**Sarge** · 04-14-2008, 10:11 AM

Indexing wont hurt anything but any gains are so minimal it renders the effort basically useless.

rednari · 04-14-2008, 10:19 PM

Indexing is not as useless as it may seem. By indexing the plugs up toward the valves and not the cylinders, the possible gain is about 2-3 HP. While the gain may seem small, it is free HP and should not be ignored. A set of indexing spacers are cheap and the set up only requires a few minutes longer when installing the plugs.

True, it is an old trick. The P-47 guys used too index and clip plugs to give our flyers an edge. They were good guys.

**Firebug** · 04-15-2008, 12:18 AM

Great write-up Sarge. I've been spinning spanners for years and never give anti-seize a thought for the plug thread. I've never broken a plug but I have left my share of knuckle skin behind when undoing plugs.

**mark21742** · 04-18-2008, 10:32 AM

hey Sarge, after reading everyones talk about what plugs to use I thought i'd throw in my $.02 I switched to autolite 103's and helped my Very slight misfire I got after the CAI and LT's

**Sarge** · 04-18-2008, 01:57 PM

Yup...experiment with plugs and gap of plugs.....you'll find the setup that works for you....plugs on the GTO's are a walk in the park compared to Fbodies for sure....

rednari · 04-18-2008, 07:40 PM

Interesting, I was considering a set of autolites too.

**mark21742** · 04-19-2008, 01:50 AM

the hardest part for me was getting the plug wire boots off the plugs, I was afraid I was going to tear them. It was still nice to do a plug change in under 15 minutes.

**Sarge** · 04-19-2008, 04:50 AM

Use the Di Electric grease and them boots slide right off....

**LETHALxLS1** · 04-20-2008, 06:34 PM

I gap my NGK tr-55 plugs to .040 in my 98 Z/28. Runs excellent.

**LETHALxLS1** · 04-20-2008, 06:35 PM

Sarge- "So blow me in advance"

**LS2Tuner** · 05-21-2008, 06:29 AM

^ Here I'll bring it back up for others that couldn't find it........^

**Goat-E** · 06-29-2009, 01:55 AM

I do basically the exact maneuver but I don't like the dial gappers at all. They wear down & compromise the gap as well as misaligning the contact points. Electricity much like water follows the path of least resistance. This creates a bias in the sparks travel. I use the old school stainless steel blades. After making sure the contact points are properly aligned, I turn the plug upside down with the wire end on a piece of wood, insert the blade & then tap the diode lightly with a light brass hammer to set the gap. Thus avoiding any misalignment and achieving a perfect gap every time.

I also use a stubby 3/8 ratchet handle with a swivel head.
If you do see a misalignment in the contact points you can straighten them with a needle nose plier . . . gently grasshopper.

**mark21742** · 06-29-2009, 04:45 AM

since this thread is back up.
I've read and heard people talk about cutting the electrode back.
what exactly gets trimed off, and does it have any advantages?

**Sarge** · 06-29-2009, 04:53 AM

Originally Posted by mark21742

since this thread is back up.
I've read and heard people talk about cutting the electrode back.
what exactly gets trimed off, and does it have any advantages?

Put on a buffalo headdress with the full train of eagle feathers. Strip buck ass nekkid and dance around your car waving your arms and screaming to the top of your lungs. I find beating any available pots and pans also helps and increases the residual effects.Keep this up until they come and take you away.
Or file down your electrodes. Both work equally well.

**mark21742** · 06-29-2009, 08:25 AM

Originally Posted by Sarge

Put on a buffalo headdress with the full train of eagle feathers. Strip buck ass nekkid and dance around your car waving your arms and screaming to the top of your lungs. I find beating any available pots and pans also helps and increases the residual effects.Keep this up until they come and take you away.
Or file down your electrodes. Both work equally well.

I already drank a half gallon of Ice Tea vodka this weekend and tried the dance......it didn't work lol
I get your point

**Sarge** · 06-29-2009, 01:45 PM

Originally Posted by rednari

Indexing is not as useless as it may seem. By indexing the plugs up toward the valves and not the cylinders, the possible gain is about 2-3 HP. While the gain may seem small, it is free HP and should not be ignored. A set of indexing spacers are cheap and the set up only requires a few minutes longer when installing the plugs.

True, it is an old trick. The P-47 guys used too index and clip plugs to give our flyers an edge. They were good guys.

And here all this time I thought it was the .50 cal's .....I'll be damned...indexed plugs dropped them Nazi sum bitches.....nah it is true...you can gain "some"...3-4 HP is probably the very best you could ever see.....probably closer to 1HP on average....

**Goat-E** · 06-30-2009, 03:51 AM

I also fiddled with a variety of gapping and .040 seems to culminate the best results. Some factory settings can't be beat I suppose. Lord knows I've read all kinds of BS postings about various gaps but had too see for myself.