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Discussion Starter #1
I have one center bolt on each side of my exhaust manifolds on my 67 GTO 400 Motor that I cannot remove. I bought an broken bolt/head extractor kit but all it did was shave the metal on the head and not grab it.
The points of the heads are rounded now on both.
Should I
#1 heat the bolt?
#2 Hand file the flat spots so I can get a boxed or a socket on it?
#3 MIG weld a new nut on top of the old head then get my oxy/aceteline and heat the bolt and smack it with a hammer to loosen the rust on the threads?. I wish I could get Kroil or PB in there.
I do not want to snap the bolt.
All the others came out with a little back and forth play.
Thanks
Jax
1967 GTO Convertible.
 

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All of your ideas are good ones. It'll need heat and patience. Worse case, the heads will have to be pulled to have a machine shop remove the bolts. I would clean up the head of the bolts with a file, heat them, and use a 6 point socket. Next step would be to weld a nut onto the bolt head and try that. Yes on the heat, and yes on the hittng with a hammer. An impact gun, if it'll fit, will work wonders IF you just goose it a little and don't lay on the power, and go both ways, over and over. If you just go full power on the impact, the bolt will snap. Impacts are great at shocking rusted bolts loose, with the right technique. Good luck, and let us know what worked in the end.
 

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Discussion Starter #3
All of your ideas are good ones. It'll need heat and patience. Worse case, the heads will have to be pulled to have a machine shop remove the bolts. I would clean up the head of the bolts with a file, heat them, and use a 6 point socket. Next step would be to weld a nut onto the bolt head and try that. Yes on the heat, and yes on the hittng with a hammer. An impact gun, if it'll fit, will work wonders IF you just goose it a little and don't lay on the power, and go both ways, over and over. If you just go full power on the impact, the bolt will snap. Impacts are great at shocking rusted bolts loose, with the right technique. Good luck, and let us know what worked in the end.
At the point of gasket replacement / exhaust manifold removal now. It is so tight at those frozen bolts. I can't even get the MIG head into the space to weld another nut over the stripped head. All of the other bolts are out and I got a full set of new bolts from Ames. I am at a loss and I am hoping that I do not have to pull the heads. Any thoughts here?

Thanks
Jax
 

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Many times the rust bond can be found where the shank has fused to the manifold vs the head. It's a crap shoot as to whether there's going to be a stub of bolt hanging out of the head if it does indeed break. If it does leave a stub you can heat it up around the head and then melt some candle wax in there. It may even work on the bolt before it breaks. A longer term penetrant process, mix ATF (not synthetic) and acetone 50/50. Go easy, but get it in there. Let it soak as long as you can and wet it again when you're ready to give it a go. Is the motor in the car? Does it run if it is? While the work area gets a bit miserable from this, let the exhaust heat the whole manifold for a few minutes.
 

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Those work good rentalguy. I have one from the 60s (!) and it's been a save more that a few times. I'm not sure which tools were already mentioned above these work really well also...

Sears.com
 

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Discussion Starter #8
I am still stuck. I tried cheating on the right side as both sides only use 5 bolts per. I got the manifold out and had it to a machine shop to grind the surface flat. One center bolt I had to cut while lifting the motor. I tried bolting it back on with the 2 front bolts, new gasket, one center bolt and the one rear. Still leaks. The left side, due to the steering column is too tight. I can either send it out and pay a fortune to lift out the motor or pull off both heads and have my machine shop re tap the bolt holes and grind the left side manifold in the spring. This is the most frustrating job on any car I have done in 50 years.
Please send anymore thoughts before it gets too cold in New York. My garages are non heated steel.
Thanks
Jax
1967 GTO
 

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Doesn't sound like you have any options left other than pulling the heads. I had a couple broken studs on my Dakota. I was able to use the style easy out where you drill the center of the broken bolt/stud and the easy out threads in reverse to work it out. There was plenty of room to do this on the Dakota, but I doubt you have room to get a drill in there on your GTO. If you remove the heads, this would probably work. I typically buy better quality tools than whats sold at Harbor Freight, but they worked great.

Screw Extractor Set 12 Pc

I am in Rhode Island and feel your pain on working in an unheated garage in the winter. I picked up a kerosene bullet heater a few years back. Makes a world of difference getting things done out there when its cold out.

Good luck!
 

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Discussion Starter #10
I have an extractor set, a bolt remover that didn't grab the head but ground it round from bolt being in so tight. I think that I am going to have to wait till spring and pull intake then one head at a time and have the studs re threaded after they remove it. Also, since heads will be out, I will have them cleaned and get valves, springs, etc cleaned or replaced. I am getting 150 psi on each cylinder but after 48 years I am sure a little tidying up can't hurt.
Jax
1967 GTO convertible
 

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I have an extractor set, a bolt remover that didn't grab the head but ground it round from bolt being in so tight. I think that I am going to have to wait till spring and pull intake then one head at a time and have the studs re threaded after they remove it. Also, since heads will be out, I will have them cleaned and get valves, springs, etc cleaned or replaced. I am getting 150 psi on each cylinder but after 48 years I am sure a little tidying up can't hurt.
Jax
1967 GTO convertible
That is where you are at now, Kroil would have worked but you have to give it time to work.
I had one stud on a Jeep water pump that I soaked, heated, tapped and wrenched back and forth for 9 days before I could get it to finally pop and come out.
Working on marine engines we deal with this all the time and you just have to be patient and let the Kroil do it's thing.
 

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Jax, you are making the right call. And with lemons, you can make lemonade and take the time with the heads getting redone to repaint the intake, and freshen up the engine compartment. On re-installation of the heads, a huge help is to install a couple of all-thread rods into the block on each bank, so when you re-install the head, (It's HEAVY), you won't slip and ruin the expensive gasket. Makes the job MUCH easier. You can also cut the heads off of a couple of old head bolts and use them as guide studs. If your engine is old and leaky, it may be a good time to simply yank it and do a complete re-seal on the engine while the heads are getting done. I did this on my own '67 back in 2011, and for the first time in 30+ years of ownership I am enjoying a totally leak free car!!
 

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Discussion Starter #13
I did soak the bolts with Kroil, PB Blaster, etc. No good. Since it is getting warmer soon, I might let the motor run and try it then. I don't want or need to pull heads if I don't have to. Good compression and no leaks, also a new aluminum Edelbrock Pontiac power 4bbl intake manifold. I took off the tri power and sold it. Engine runs better with 4bbl stock carb. Question, how hot can I Heat the head to try to remove bolts? Oxy/aceteline or a Bernz o magic torch? I don't want to warp head. This will be my last attempt. If it works on passengers side, I will pull steering column again for access on drivers side.
Thanks
Jax
1967 GTO Convertible
 

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Good luck and since they have been soaking for awhile you might get them to pop loose.
You could try a propane torch, I wouldn't use oxy/acet unless you are very experienced with it.
If you can get a good purchase on them and apply torque and smack them with a hammer they may pop loose.
Kind of hard with limited clearance.
When you do get them out remember to use anti-seize on the new ones so you don't have this problem again down the road.
 

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Heat just the head around the bolt, not the manifold. You shouldn't be able to warp it. After heating I would hit the manifold with an air hammer right on top of the bolt. Be sure to use a 6 point socket, Also put two or more bolts back in to support the manifold so the weight of the manifold is not fighting the bolt. Good luck.
 
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