I removed my crossover pipe to do some work and can't for the life of me drill the bolts out of the exhaust manifolds. Removing them to do on the bench isn't an option for me. This is on my '83 and the project has been stalled since May as a result.

My question is, would it be cheaper for me to bring the car to a muffler shop or my regular repair shop to have it taken care of? Or would it not make a difference? I thought I read somewhere that the quickest, easiest way would be to melt the remnants out with a torch and I'm thinking the muffler shop would be better equipped to tackle that, thus cheaper. Opinions?

 

I'd think a muffler shop would deal with issues like that more often

 

So you've been stalled for five months because you can't remove the manifolds?

Why not just remove the manifolds?

- Eric

 

Spend some money and some really good drill bits (cobalt?), in a few sizes, starting smaller, maybe 1/8". Use a dremel with a cutoff blade to cut a cross in each bolt, to provide a centered starting point for the smallest drill bit. When you are done, instead of tapping your new hole, you can use a throughbolt instead.

Steve

 

^^^This!

 

I can just about guarantee the exhaust manifold bolts will snap off in the head. Not exactly easy access on the smogger 307 either. That and the AIR tubes will crumble if disturbed. Not about to pull the engine on this thing yet.

 

Then take it to a muffler shop, and they will drill through approximately where the bolts were, and install through-bolts.
Without a lift, you'd be a glutton for punishment to be doing it on your back.

- Eric

 

The A.I.R. tubes screw into the heads above the manifolds. You should not need to touch them. All but the center manifold bolt are in through holes - spray a good penetrating oil in the backside and let them soak overnight. Frankly, if the motor is this rusty, you have other problems.

 

In that case maybe I'll have some luck then, I'll have to give that a try. It's not terribly rusty, just the usual corrosion. I've been busy with my '65 I haven't really looked at it. Ideally I would get them off and take them to a machine shop and do it right. Good tips, good tips.

 

The other tip is that an impact wrench works wonders on rusted fasteners. I realize that space is limited to reach the manifold bolts, but if you can use a right angle impact, you'll have those bolts out with no concerns.

 

Also, depending on what else you're in the middle of, and other circumstances, sometimes you can remove a fender liner and get close to a straight shot at the manifold bolts from the side.

- Eric

 

Well went to remove one and it snapped off like I expected. It's a puny 12mm nut on a stud. Not removing the manifolds..

 

I'm not familiar with the later cars, but I thought all exhaust manifold screws had 9/16" heads and were 3/8"x16 threads.

- Eric

 

I understand if you don't use a torch and heat things up cherry red you get a lot of broken bolts on through bolts.
I don't understand way you can't drill out the broken ones, tell use who you are attempting to do this, I have done this many times and maybe it's just your technic.