Jet-Jock

I just ran across this which is an AC/Delco installation note:

Do not use any type of anti-seize compound on spark plug threads. Doing this will decrease the amount of friction between the threads. The result of the lowered friction is that when the spark plug is torqued to the proper specification, the spark plug is turned too far into the cylinder head. This increases the likelihood of pulling or stripping the threads in the cylinder head. Over-tightening of a spark plug can cause stretching of the spark plug shell and could allow blowby to pass through the gasket seal between the shell and insulator. Over-tightening also results in extremely difficult removal.

Wondered what all of your thoughts on this is?

bogus

that is a real possibility... however, I have never been able to get a plug in with a torque wrench... there just isn't any space for one to fit!

So, I use a method similar to tightening an oil filter... get it in, turn it until its snug, and then 1/2 turn more.

It's close enough...

and yes, anti-seize will throw the amt of torque required off, by as much as 60%!!

jackdaroofer

but a good anti seize may make it a lot easier to remove the plugs 70 to 100,000 miles down the road

Torgue on the plugs is about like bogus described it, not much

I'd use the anti seize, but not the copper based stuff since copper and aluminum don't get along real well. there is an aluminum based anti seize. somewhat hard to find at times, it comes in a pencil like stick

seeya

Jet-Jock

Hmmm, I was able to torque all mine. It's a mind trip to find the angles.

Ya know I looked for aluminum anti-seize, no one has ever heard of it (all the major parts stores). So I've been using the NAPA copper stuff.

But I wondered about this since almost everyone here recommends anti-seize and here GM was saying don't use it.

FELNGR8

How are you going to stretch a steel spark plug without yanking the threads out of an aluminum head. Face it, the threads are the weak point and the reason the torque setting is only 11 ft-lbs. How are you going to stretch steel at 11 ft-lbs?

Are you sure that note doesn't refer to iron heads?

c4cruiser

I used some Permatex Anti-sieze on my 92 heads but a very small amount, only a couple threads worth and very light. Didn't use a torque wrench but 11-15 ft-lbs is not a lot of torque. As mentioned, it will be a big help when the plugs are removed years later. Just make sure that the engine is COLD when you pull the old plugs.

The GM service manual does not mention using anti-sieze for plug installs but it doesn't say not to use it. AC Delco may be talking about generic applications rather than Corvette-specific. Even though they may be part of GM, I would go by any specific instruction in the GM manual regardless of what AC Delco recommends.

JrRifleCoach

My guess is this installation note is for iron heads. What I have learned from aluminum head aircraft engines is that a special thread lube is always used. This lube is specifically formulated to transfer heat across the threads. If you use regular antisieze, it will insulate the heat in the plug. Granted some of the heat will pass to the head. But not all the heat that the plug is rated for. Using the wrong thread lube product will cause early failure of the plugs. Remember, I'm talking aircraft which is ten times more **** than Corvettes. (hard to imagine in some cases)

Torqueing iron head plugs with the crush washer I can see going a half turn from snug. But putting a half turn on taper seat plugs in an aluminum head is with or without lube. Best use a torque wrench if in doubt.

skeet

Most aircraft supply shops have a special anti-seize for aluminum and for the electrical considerations (resistance,etc) of spark plugs.. That is what I use.It is made by CHAMPION, part # 2612, and is called "Spark Plug thread lubricant and anti-seize Compound". It is graphite based, conductive and only should be applied to "the second and third installation threads...do not apply to the sheilding barrel threads".

tjwong

I have used a nickel based antiseize compound on all aluminum heads be they a corvette head or a rice engine head. In all my years I have never had a problem. I have had more problems with removing plugs that some anus didn't use any AS compound. As for torque applied to the plug, I haven't used a torque wrench on a plug in years. I don't ape them on either but I haven't had fome come loose yet.

AQUADEN

I just put plugs in mine the other night.Motocraft double platinum,the APP ones.The AC's that were in it had so much of the copper based anti-seize on them that they were gummy and a bit difficult to remove.I had to use the ratchet until they fell out.I use the silver Permatex anti-seize and have always had good results.Just don't overdo it and that goes for tightening them too.
By the way,only one plug had a puck on it.Friggin AC's

onedef92

I used anti-seize compound on my 92 LT1 (aluminum heads.) As others have said, don't do the torque wrench or go-gorrilla on the plugs and they'll be a lot easier taking them out next go round.

Texas CE

When I replaced my plugs I used Permatex Anti-sieze that was silver. I put it on all the threads and then tightened the plugs until I felt the washers crush.

Obviously I did it wrong 2k miles ago so I better break out the wrenches again!

Jet-Jock

Hmmm, first time I used just a small amount. Like one comment said it was gummy when I removed it. That didn't dawn on me, I coated all the threads on this latest install. Guess I am going to be removing the plugs tomorrow when I swap out wires. Dang it!

Jet-Jock

Ok ya'll are making me do work.... this is from Permatex's site:

This is for the cooper stuff:

Permatex® Copper Anti-Seize Lubricant
A premium quality copper anti-seize and thread lubricant that may be used to prevent seizing, corrosion and galling where high temperature conditions exist. Contains a high percentage of micro-fine copper flakes in a semi-synthetic grease carrier and is fortified with high quality rust and corrosion inhibitors. Temperature range: -30°F to 1800°F. Provides good electrical conductivity. Meets Mil Spec #907E.

Suggested Applications:
Spark plug threads installed in aluminum, exhaust manifold bolts, engine bolts, oxygen sensors, knock sensors, thermostat housing bolts, fuel filter fittings, and battery cable connections


This is for the regular stuff:

Permatex® Anti-Seize Lubricant
A highly refined blend of aluminum, copper and graphite lubricants. Use during assembly to prevent galling, corrosion and seizing and to assure easier disassembly. Temperature range: -60°F to 1600°F. Salt, corrosion and moisture resistant - ideal for marine use. Non-aerosol version meets Mil Spec #907E. Level 3

Suggested Applications:
For easy removal of spark plugs, cylinder head and exhaust head bolts.

And the nickel stuff:

Permatex® Nickel Anti-Seize Lubricant
Protects metal parts from seizing and galling at temperatures up to 2400°F. It is recommended where copper contamination must be avoided, under conditions of extreme pressure and temperature, and with stainless steel, titanium and nickel alloys.

Suggested Applications:
N/A


It appears that the cooper stuff is the correct product to use. But now why would GM say that? I'm still trying to find a good source for all GM Technical Bulletins.

I got the original quote from an article.

Vic'89

I have never torqued a spark plug in any car I have owned.

I have ALWAYS used anti-seize on any bolt that goes into Aluminum.

Vic

C5Jimmy

Wow, I didnt know that! I used Never Seez on my plug when i had my motocross bike, but I just snugged it and that was it, no probs....

Caboboy

Same here, both counts On plugs, I use the "snug and a bump" rule.

cmontel727

I always have used the copper a/s and just snugged the plugs. No problems on any of my cars with aluminum heads. Oldest car has 175,000 with many plug changes.

CFI-EFI

I have an 8 ounce plastic "can", of the aluminum anti seize. It looks like a life time supply and came with an applicator brush attached to the cap. Permatex part number 133K.

If you're using u joints or have any other kind of "angles", your torque readings are pretty much meaningless.

RACE ON!!!

FELNGR8

I once broke a set screw replacing a distributor cap on my Honda. Forearm twisting torque on a screwdriver. This little screwup cost me two break downs on that motor.

I don't trust my sense of strength when tightening anything. I take the time to torque plugs in the aluminum heads of my Vette, and I can reach 'em all with the torque wrench.