Thoughts on spark plug torque
08-26-2013, 09:49 PM
#11
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Join Date: 01-13-2008
Location: Washington State, where it rains
Posts: 4,708
There are some things like spark plugs and wheel lugs that go in dry...adding a lube like anti seize is inviting vibration loosening..and as for plugs, this would also affect the heat transfer in the plug zwhich would change the heat range designed in....just some thoughts...some from actual experience
08-27-2013, 12:16 PM
#12
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Join Date: 11-19-2008
Location: oregon
Posts: 123
I'll give a report later this summer after I change plugs.
My plan now is not to use anti-seize.
Why:
1. Supposedly, anti-seize can increase the effective heat range of a plug - via reduced heat conduction.
2. Threads create a huge lever. Over-torquing creates stress on the insulator/shell seal beyond that intended by design.
I have to admit, if the original plugs are difficult to remove (86 k mi), then I won't be able to resist getting out the anti-seize. But for now, I have to assume that the plating/coating already on the new plugs will do the job.
I will have both a clicker and beam type torque wrench available. I think either would work. I wonder if using a beam type, and keeping the torque on the plug for a few seconds, would at least make one "feel better", and lessen the urge to tighten a wee bit more.
My plan now is not to use anti-seize.
Why:
1. Supposedly, anti-seize can increase the effective heat range of a plug - via reduced heat conduction.
2. Threads create a huge lever. Over-torquing creates stress on the insulator/shell seal beyond that intended by design.
I have to admit, if the original plugs are difficult to remove (86 k mi), then I won't be able to resist getting out the anti-seize. But for now, I have to assume that the plating/coating already on the new plugs will do the job.
I will have both a clicker and beam type torque wrench available. I think either would work. I wonder if using a beam type, and keeping the torque on the plug for a few seconds, would at least make one "feel better", and lessen the urge to tighten a wee bit more.
09-01-2013, 01:34 PM
#13
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Join Date: 12-19-2008
Location: dfw texas
Posts: 234
really hard to pull plugs
I've always used a clicker type wrench, beam wrenches are a bit old fashioned and and inaccurate compared to a freshly calibrated clicker wrench.
One thing that seems to have escaped mention, always change the plugs on a cold engine, changing them without letting the engine cool down is courting disaster.
And even though they are brands that HHR's hate. NGK, Bosch, and Denso specifically recommend against using anti-seize in aluminum heads because it can give false torque readings leading to over-tightening.
GM does not recommend its use because the metal plated shells on Delco plugs(Zinc or Nickel plated), will provide the proper torque characteristics when installed dry, no anti-seize compounds needed or advised.
One thing that seems to have escaped mention, always change the plugs on a cold engine, changing them without letting the engine cool down is courting disaster.
And even though they are brands that HHR's hate. NGK, Bosch, and Denso specifically recommend against using anti-seize in aluminum heads because it can give false torque readings leading to over-tightening.
GM does not recommend its use because the metal plated shells on Delco plugs(Zinc or Nickel plated), will provide the proper torque characteristics when installed dry, no anti-seize compounds needed or advised.
09-01-2013, 02:00 PM
#14
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Join Date: 06-30-2010
Location: Kannapolis NC
Posts: 25,739
Yeah I've had a couple come out hard, just hard enough to cause heart failure until I was sure the threads didn't come out with the plugs.
You're dealing with steel shelled plugs in an aluminum head, so it might be a bit of corrosion or carbon buildup holding them back.
One trick from the techs who work on Quad 4's and Northstar V-8's is to dribble a bit of penetrating oil like PB-Blaster around the plugs, drive the vehicle which lets the engine heat pull the penetrating oil down farther, then let 'em cool down again.
It's time consuming, but the plugs will come out much better.
I don't think a drop of the Lucas juice will harm anything, It's when the threads are gooped up with anti-seize that you can over torque them by accident.
You're dealing with steel shelled plugs in an aluminum head, so it might be a bit of corrosion or carbon buildup holding them back.
One trick from the techs who work on Quad 4's and Northstar V-8's is to dribble a bit of penetrating oil like PB-Blaster around the plugs, drive the vehicle which lets the engine heat pull the penetrating oil down farther, then let 'em cool down again.
It's time consuming, but the plugs will come out much better.
I don't think a drop of the Lucas juice will harm anything, It's when the threads are gooped up with anti-seize that you can over torque them by accident.
09-01-2013, 02:39 PM
#15
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Join Date: 12-19-2008
Location: dfw texas
Posts: 234
tried it dry, looks similar
I went ahead and tried installing that first plug dry, torqueing by hand first, then checking with torque wrench. Then I pulled it out again. The plug came out smoothly, and had the same discoloration as the old one. That must be the coating from the factory. Did the same on the second plug (which came out even harder). Same. By the way, I did the Quad4 trick on, yes, my Quad4. I didn't really care if it would harm the combustion anyway, because I had already decided to run it 'til it died and get a HHR. Thanks for your reply, I just wanted a second opinion to confirm what I suspected was true. I don't think I'll use any lube after all.
09-01-2013, 05:24 PM
#16
Senior Member
Join Date: 10-19-2011
Location: N.Y.
Posts: 1,553
I'll give a report later this summer after I change plugs.
My plan now is not to use anti-seize.
Why:
1. Supposedly, anti-seize can increase the effective heat range of a plug - via reduced heat conduction.
2. Threads create a huge lever. Over-torquing creates stress on the insulator/shell seal beyond that intended by design.
I have to admit, if the original plugs are difficult to remove (86 k mi), then I won't be able to resist getting out the anti-seize. But for now, I have to assume that the plating/coating already on the new plugs will do the job.
I will have both a clicker and beam type torque wrench available. I think either would work. I wonder if using a beam type, and keeping the torque on the plug for a few seconds, would at least make one "feel better", and lessen the urge to tighten a wee bit more.
My plan now is not to use anti-seize.
Why:
1. Supposedly, anti-seize can increase the effective heat range of a plug - via reduced heat conduction.
2. Threads create a huge lever. Over-torquing creates stress on the insulator/shell seal beyond that intended by design.
I have to admit, if the original plugs are difficult to remove (86 k mi), then I won't be able to resist getting out the anti-seize. But for now, I have to assume that the plating/coating already on the new plugs will do the job.
I will have both a clicker and beam type torque wrench available. I think either would work. I wonder if using a beam type, and keeping the torque on the plug for a few seconds, would at least make one "feel better", and lessen the urge to tighten a wee bit more.
Everyone seems to have different ideas on the use of anti seize
Copaslip is what I have been using for the last couple of years since I was told about this product,it has been extensively tested on some big dollar motors.It is copper based.
And yes different oils grease etc. will effect the torque of a given threaded apllication.You can also get a very false reading from a dry to dry thread application especially if the threads have some carbon build up on them
There is a reason why ARP makes there fastener assembly lubricant.( note not for spark plugs)
So just my opinion
I use a very small amount of copaslip a dot is sufficient on the threads.
http://www.mrmoly.com/html/copaslip.html
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