Did I screw up my heads???

oldmansmonte

oldmansmonte

G-Body Guru
Oct 29, 2010
528
63
Buffalo, NY
Backstory: 85 Monte, SBC 350 crate motor(Iron block and heads) installed 9 years ago. Runs good. One day the engine started ticking very noticeably(3/4 years ago?). Sounded like it could have been a lifter or otherwise. Couldn't figure it out for the life of me. Took it to a shop they said I had some loose spark plugs. I had them put new plugs in. To my relief the problem went away. Not long after it started coming back. Upon inspection I had loose plugs again. I researched what could cause loose plugs on an SBC and the common answer was using never seize on the plugs, which I had done years before. I know what you're thinking, what a dumbass! I sometimes can't help myself and I overdo things.

When I pulled the new plugs I found they had used a small amount of copper on them(like a normal mechanic would). So now I had a slurry of never seize and copper on the threads. So I used various methods to clean the threads in the heads. Q-tips with brake clean, rags, cutting of sponges to finger size pieces and working the threads, then installed new delco plugs again dry this time and it's still happening. Now since I have headers some of these are practically impossible to tighten down. A friend suggested a socket SLP made for the F-body LT1 cars where the plug goes right through the socket and it has 13/16 adapter right on it that you tighten down. Now I have much better ability to tighten them down and yet they are still coming loose. Not nearly has bad as before, but even after a single drive I hear a fluttering sound echoing outside of the car as I drive and the next day when I check it, one of 4 plugs will be loose. 3,5,6 or 8 seem to be the problem.

I see only 2 possibilities: I either over tightened those when I had the never seize on them and didn't realize it(and messed up the threads in the heads), or I'm not tightening them down enough now because I don't have adequate room and I'm afraid to over tighten them.

Any thoughts, advice or comments would be appreciated.
 
83MonteCarloSS

83MonteCarloSS

Not-quite-so-new-guy
Oct 5, 2015
48
18
Lock 'em down. I wouldn't be worried about over torquing them unless you've got aluminum heads. If you stripped the heads I think you'd know it. I have one that's a pain to get to with my headers. I can torque it down with a wrench luckily. Good luck!
 
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1983calais

1983calais

Master Mechanic
Supporting Member
Feb 26, 2015
276
63
Tiffin, OH
Do you have tapered plugs or flat with the gasket? Maybe you have the wrong plugs for your heads.
 
pontiacgp

pontiacgp

blank
Mar 31, 2006
28,476
113
Kitchener, Ontario
anti seize will not help a plug to loosen, the reason they say not to use it is because it is a lubricant and you may over torque the plug.
 
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oldmansmonte

oldmansmonte

G-Body Guru
Oct 29, 2010
528
63
Buffalo, NY
Lock 'em down. I wouldn't be worried about over torquing them unless you've got aluminum heads. If you stopped the heads I think you'd know it. I have one that's a pain to get to work my headers I can torque it down with a wrench luckily. Good luck!

Thanks I appreciate the advice. Worst case scenario, If I trash them, I can always
Crank them in tight, and forget it. Do you have the right type of plugs in there (Tapered or gasket seat)?
It’s the Delco R44LTS, the plug recommended for that motor from the owners manual. GM crate motor with iron vortec heads.
 
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oldmansmonte

oldmansmonte

G-Body Guru
Oct 29, 2010
528
63
Buffalo, NY
anti seize will not help a plug to loosen, the reason they say not to use it is because it is a lubricant and you may over torque the plug.
This is what I’m afraid I did in the past. Maybe over torqued combined with bad approach angles. Generally speaking I don’t rail sensitive things on but maybe the “lube” allowed it to happen.
 
79 USA 1

79 USA 1

G-Body Guru
Sep 2, 2011
634
93
Cheektowaga, New York
Taper seat plugs I've always seated them finger tight then tightened them 1/16-1/8 turn farther. When using anti-seize I'll use just a light dab once every three plug changes.
A easy wrench to make for getting behind headers can be made with a 5/8 12 point box and lots of heat. I made this one years ago and it works great behind the header tubes for cylinder 3, 5, 4 & 6.
P1012237.JPG P1012238.JPG

Sorry for the poor picture, camera has seen better days.
 
oldmansmonte

oldmansmonte

G-Body Guru
Oct 29, 2010
528
63
Buffalo, NY
This is what I’m afraid I did in the past. Maybe over torqued combined with bad approach angles. Generally speaking I don’t rail sensitive things on but maybe the “lube” allowed it to happen.
If this is the case those heads are toast right?
 
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