Broken exhaust bolt. Can I do this

[Rover]

From your photo it looks like you have a clean shot with a drill,correct?
This metal is soft, drill out the bolt.Start with small bit(centered as much as possible)if you hit the threads tap new ones.Try not to enlarge the hole more than original.I'd cut the bolt flat to get a good start in the center.
Behind a down tube is another matter.In that situation I would take the engine out.

[climberpilot]

I have a similar mess on my hands. As soon as I have a sub-13 hour workday I'm gonna go buy some left hand bits and a heat gun to warm up the casing.

[Quick Cal]

So do you guys see the head gasket. Do you think I will toast it with too much heat. Thanks.

[GateKeeper]

By doing a search, I read a post where the members were saying get the bolt red hot. It won't do it with my torch. Again. Maybe I'm just afraid to leave it on there long enough. I've been leaving it on there for about 30 seconds. I sure hope I didn't all ready trash the gasket.

30 seconds will probably not get it hot enough, if you ever did any plumbing work with the copper pipes and fitting you need way more heat time even with those to make them hot enough to make a good solder connection.

the head gasket might take a beating, hard to say, you could try and put a wet towel on the area you don't want the heat transferred this might help a bit, point the flame upwards and heat the broken bolt from the bottom ?

if all this fails you will need to drill it out....

but since you have so much of the bolt sticking out it's probably easiest and fastest to get a nut welded on and have it removed, the best way probably, and the one that will cause the least amount of damage or worry..

.

[Spyder]

What exactly are you using red loc-tight for???

get your vice-grips clamped on it as tight as humanly possible... heat the aluminum, inside th exhaust port. move the bolt back and forth (loose and tight) if/when it does start to move, keep going a little farther loose with each swing...

Also, aluminum will not get red hot, it will melt long befor that happens. A small propane torch shouldn't be able to melt your head though...

[capnjim]

Ditto with trying again with vise grips. Squeeze those suckers as tight as possible..if it snaps off, you will have to drill it out and re-tap for a new bolt which isn't the end of the world.

[Nessism]

The heat is to break down the chemical corrosion bond, not to expand the aluminum. Heat and spray with pent. oil a couple of times. Since you have that nice big nub I'd try the vice grips, but don't break off the nub - leave enough to weld on the nut in case you need to.

[Quick Cal]

The vise grips will not go on sideways. I have to grip from the end of them,,if you know what I mean. I'm going out now to give it another try.

[Killer2600]

The vise grips will not go on sideways. I have to grip from the end of them,,if you know what I mean. I'm going out now to give it another try.

I'd go the welded nut route, vice-grip are crap in a straight-on fashion.

[salty_monk]

I went to studs like those from Napa (same as above - also $8). They were cheap, rusted very quickly & made it a real PITA to get the exhaust on (aftermarket 4:1).

I went back to bolts... I drilled the mirror to that one on the other side with left handed bits. Ended up Helicoiling it. It was fairly simple to do. I had to buy an "inline" tap wrench - the kind that fits on a socket wrench to tap it was all.

The trick with vice grips is to buy one of the better quality sets with hard biting teeth. Some of the cheaper sets out there are really junk. Too much slop in the linkages & thread & soft teeth etc.

[Quick Cal]

Yep. That's the problem I'm having with the vise grips. They're the junky kind that the jaws just keep going sideways. I'll keep playing with it until it's time to load it on the truck to take to the welder.