Here's a tip about spark plug threads

Zeke · 08-05-2003, 06:25 AM

While I was buying some Aeroquip oil line fittings, the man said to wire wheel the threads at the adaptor union to ensure an excellent joint. Later that day, the guy where I buy my Bosch plugs told me to do the same to the plugs. He says it smooths out the plating and very slightly rounds off the sharp edges of the plug threads. Much less apt to seize in the hole and strip out the threads on removal. I did the hose, but haven't installed the plugs yet. I will use a trace of anti seize for insurance.

Jim Sims · 08-05-2003, 06:37 AM

If the threads are plated with an anti-seize material such as silver using a wire wheel will strip off the plating and leave the plug in worse condition for galling. Jim

Zeke · 08-05-2003, 07:01 AM

The plugs I buy are not coated. Just anodized to the best of my knowledge. Which ones are? I don't want to spread bad info. Sure worked great on the Aeroquip. Requires a light touch on the aluminum or you will be worse off.

IROC · IROC's Garage

I'm a firm believer in using anti-seize on spark plug threads. Never had a problem as a result.

Mike

Randy Webb · 08-05-2003, 04:03 PM

I'd bet the quality plugs don't need this as the threads are prob'ly not "sharp" any ways. You might check -- rub it on your face (this also impresses women). I'd be cautious with the wire brushing duration & pressure.

Be careful w/anti-sieze on catalyst/sensor cars.

Schrup · Schrup's Garage

I noticed Wayne suggests to not use anti-seize on plugs in his book.

After reading a couple threads about galling I went ahead a used a little silver stuff, I certainly don't want those kind of problem$$.

CarreraS2 · 08-05-2003, 04:15 PM

Milt, maybe try a bit of WD-40 on 'em!

TimT · 08-05-2003, 04:39 PM

Anti-sieze is usefull stuff. One problem is people use to much of it.

Some also have concerns that some anti-sieze compounds are not conductive, and that may raise ignition problems by not allowing the spark plug to be fully grounded. I believe that is BS. The anti-sieze fills all the teeny lil voids between the threads. When you tension the plug ( bolt, nut etc.) the compound will be forced to fill the irregugularities that exist between the plug threads and the threads of the cylinder head.. There will always be enough contact between the plug and cylinder head to assure a good ground.

The amount of anti-sieze that I would use on a sparkplug would amount to the equivilant of a small booger. Ive worked on cars where I have removed a plug ( or lugnut) that had way to mush anti-sieze applied... the wheel had streak of anti-sieze running to the perimeter.

This is a case when less is better than more..

Formerly Steve Wilkinson · 08-05-2003, 04:47 PM

We absolutely, routinely use anti-sieze--Champion makes the liquid, brushed-on compound of choice--on aircraft-engine sparkplugs. You can be as compulsive as you wish about what you do to a 911 engine, but you don't have to fly behind it.

Stephan

island911 · 08-05-2003, 04:49 PM

Quote:

Originally posted by Jim Sims
If the threads are plated with an anti-seize material such as silver using a wire wheel will strip off the plating and leave the plug in worse condition for galling. Jim

Listen to Jim.
Plugs threads are often plated with an anti-seize material such as silver.

Randy Webb · 08-05-2003, 04:51 PM

there are conductive anti-sieze types available.

Note that anti-size will alter the torque specs.

island911 · 08-05-2003, 04:53 PM

Stephan, do you change your airplane plugs while flying?

galled threads have an AOG (Aircraft on Ground) failure mode.

island911 · 09:27 PM

Quote:

Originally posted by Zeke
"He says it smooths out the plating . . ."

The plugs I buy are not coated. Just anodized to the best of my knowledge. . . . .

Sparkplugs will not have anodized threads unless they have aluminum bodies. OTOH, the Aeroquip oil line fittings would be anodized.
edit:
per www.NGK.com

Quote:

The previous plating used on NGK plugs was hexavalent (gold colored). Due to environmental issues, NGK has changed the plating to trivalent (silver colored). The purpose of the plating was to prevent corrosion on the plugs. The new plating actually is better at corrosion protection.

cegerer · cegerer's Garage

Maybe just dumb luck, but I've never used compound and have never had a problem with plugs seizing or cross-threading or whatever. I attribute this to using the factory sparkplug wrench (quite possibly the best tool ever designed, period!) and removing/installing only when the engine is stone cold. -- Curt

73911guy · 08-05-2003, 06:23 PM

If I spent the bucks to buy Aeroquip fittings and the guy at the counter told me to wire brush the threads I'd hand them back to him and ask for my money back.

If I wire brushed the threads on my spark plugs I'm sure they'd be galled so well I'd have to buy new heads. Just my luck.

Sounds like bad advice times two.

Jim

RoninLB · 08-05-2003, 06:47 PM

Quote:

Originally posted by Randy Webb

there are conductive anti-sieze types available.

yep..
it's what I use. it's vastly more conductive than the routine copper

Zeke · 08-05-2003, 07:20 PM

Quote:

Originally posted by 73911guy
If I spent the bucks to buy Aeroquip fittings and the guy at the counter told me to wire brush the threads I'd hand them back to him and ask for my money back.

If I wire brushed the threads on my spark plugs I'm sure they'd be galled so well I'd have to buy new heads. Just my luck.

Sounds like bad advice times two.

Jim

Well, the Aeroquip advice comes from Baker Precision Products. Check out their website if you care to. They have one of the largest stocks of standard and metric fittings locally. Many race local teams go there. I have to stand in line. You go to your place and I'll go to mine.

As far as the plugs, I guess I mistakenly called the plating on the threads anodizing instead of plating, Excuuuuuuuusssseee me, sir. The advice to wire wheel (with a soft wheel, I should have stated) comes from an off-road VW builder. Those 4 bangers like I have in my 914 see some pretty good head temps.

So much for "tips."

Randy Webb · 08-05-2003, 07:52 PM

'So much for "tips."'

It was good of you to make your initial post. There are different opinions out there, some based on better investigation that others. Someone can do search years alter and hit this thread and then draw their own conclusions. If you thought this was "diverse" you should have seen the recent aerodynamics thread...

RoninLB · 08-05-2003, 08:36 PM

Quote:

Originally posted by Zeke
Well, the Aeroquip advice comes from Baker Precision Products. I have to stand in line.

Hey Zeke.. Randy speaketh good

and Baker .. is this old man Baker that just moved his shop within the past three years?? maybe in southern Oregun, or northern Calif. ..
is this Baker who does all that Weber design work tooling techniques? is this Baker who built a whole/complete/including block, engine in a machine shop in High School? is this Baker the Mechanical Engineer??? .....................Ron

RoninLB · 08-05-2003, 08:45 PM

Quote:

Originally posted by TimT

may raise ignition problems by not allowing the spark plug to be fully grounded. I believe that is BS. ..

LOL.. somehow I remember those words.. and to save you from some work, LOL.. it ended in a photo finish, LOL...........Ron