Technical Stuck exhaust manifold bolt…

One thing about heating that bolt, you have to kinda play blacksmith.
Slowly bring the head up to red. Then pull the torch away and just keep the head red for a few minutes.
The heat will wick through the bolt and get to the threads.
Then walk away for a few hours. When that side feels to the touch as the other side, then try to remove it.

 

Same torch. Ace Hardware should have what you want.

 

Thanks for all the great advice! Seems the common thread here is heat.
Fortunately, the inner fender wells are not installed yet, and with the front wheel removed, I have good access. Hopefully will be able to get to it today, but it is my wife’s birthday, and the “honey-do” list never ends…

 

I actually picked up the “map” gas torch kit from Ace Hardware yesterday…

 

OOH, I like those!

 

Have you been able to get it out yet?

 

Id just cut the head off and hit with heavy penetrant. Work manifold off and then use good vise grips on the remaining stud

 

Cut the head of the bolt off, heat the manifold around the bolt to a cherry red state, let cool for 5 minutes, THEN finish quenching with a good graphite based penetrant. Never had that process fail.

 

I found time to put it through two heat cycles on Friday, busy with the family this weekend, hopefully gonna put it through another heat cycle tomorrow, then try one of my new bolt “extractors”… I will post the results tomorrow.

 

If that fails, I will cut the head of bolt off. It’s in an awkward position to use a cutting wheel…

 

So when you do the heat thing, try what I explained several posts back. Takes some time for heat to travel. Then the exhaust manifold will absorb some, it’s why I mentioned keep it red for a few minutes. Let that heat get into the threaded area and expand the bolt.

 

I have been keeping it hot for about 5 minutes each time…
Using my new map gas torch!

 

when you have the bolt hot try to turn it right like you a tightening it with a wrench.it may not be stripped out in that direction if you can get it to move you can sometimes work it back and forth till it frees up

 

After the heating and waiting trick fails it's time to get out the cold chisels and the BFH, the goal is to use the chisel to turn the bolt, if that doesn't work, use the chisel to cut the bolt head off. Best of luck with your project.

 

My original plan was to bust the cast iron manifold off with a cold chisel in an impact hammer, then wiggle the bolt back and forth with vice grips and the judicious use of penetrating oil, thereby loosening it up. Evidently, nobody thought that this was a good idea …

 

We all thought you were trying to save the manifold.

 

No, just a pair of stock small block mismatched manifolds. I’ve broken cast iron before, but never on purpose! Every bolt but one came out fairly easy…

 

Okay, after several heating and cooling cycles, the bolt hasn’t moved. I’m concerned that if I cut the head off and it’s stuck in the manifold vs the head, I would be screwed working the manifold off.
Now I’m back to the air hammer idea. I got out the one that I inherited from my dad that probably hasn’t been used in 20 years (if ever) and of course it didn’t work. Just ordered a new one from Ingersol Rand, and hopefully that will do the job. Plan is to try on the manifold that’s off and see how well it works. Has anybody done something like this?

 

I think the Mapp gas thing did not work because it doesn't have the ability to get things hot enough. Sometimes even an ox/acy torch doesn't work. No matter how you gain access to the bolts shank, you most likely will still have to deal with the threads being stuck in the head.
You can bust the manifold, but will most likely find it to not break just where you need it. If you grind the head of the bolt off, and the manifold doesn't come off, you can still do the manifold breaking thing. I would use a thin slitting wheel (and gloves and facemask) and remove the bolt head. It can even cut into the manifold as you remove the head. Once its removed, smack the manifold and maybe pry a little to see if it will come off.
If that didn't work, then take the cut off wheels and start cutting the manifold away . Some nicely placed cuts should allow the manifold to crack apart with some lighter hammer blows. Maybe even a chisel in the slit as well.

 

When pulling headers on my 56, one of the bolt heads stripped, and was pretty tight to the header tube. I cut the head off, using a small cut off wheel from various vantage points. Header came off, and was able to work the leftover bolt out of the head.

 

Most of us have been through the broken bolt adventure. Many of us swear by thread coatings (teflon, copper coat, threadlocker, anti-seize or oil) because of that experience!

 

I will definitely try cutting the head off the bolt first. I usually don’t have a problem with using a cutting wheel, but it is an awkward place to hold the grinder. It will have to be done from under the manifold…

 

If the grinder/cutoff wheel thing is to difficult to get a good position, you could also drill a hole from about the 2:00 position on the bolt head, which looks like it would be easy to get at, and angle the drill towards the shank of the bolt. Start with a small bit, and work your way up to one the same size as the shank. The head will fall off, and then hopefully the manifold will be loose.

 

If an angle grinder wont get the head off, then just get an inexpensive Harbor freight 3" grinder. Like this:
https://www.harborfreight.com/6-amp-3-in-high-speed-electric-cut-off-tool-59248.html
Or this:
https://www.harborfreight.com/power...in-angle-grinder-with-slide-switch-58089.html
Might take the guards off to let the tool get into a tight spot.

These aren't very large, and since you aren't worrying about the manifold you can cut into it if necessary to remove the head. Once the head is off it will relieve the torque on the bolt and relax it. Then if the bolt is stuck in the manifold you can grab each end and start wiggling it up and down like you were trying to tighten or loosen the bolt. You can also spray some penetrant around the bolt after the head is cut off.
After the manifold comes loose you'll be able to get a good grip on the bolt to loosen it too.

 

GRIND the head off the bolt , bad spot to try & cut it off .I'll join others in that the bolt threads are stuck in the head , not the shank in the manifold .
Only other thought is cut a screwdriver slot in the bolt head & use a hammer driven impact driver
You can also drill the head off the bolt .

 

You might try using a cutoff wheel to cut a slot in the head and use an old fashioned impact tool with a straight screwdriver bit. With the heat you've already put in it plus the hammer blows, it might come loose.

Gary

 

Use a cutoff wheel to cut an X in the head then chisel the head off.

 

Great minds ..LOL

 

Odd looking manifold...

 

I hate ruining parts (one man's junk is another man's treasure that MIGHT be useable on another tight installation) so if the impact wrench doesn't do it, I'd grind the head off the bolt (or drill it off) and use the manifold as double-ended 'wrench' to slowly loosen the bolt (if the bolt is rusted in the manifold.
Good luck!