Broken exhaust manifold in the block, how to remove?

Got a 401 block I pulled the other day. When I pulled the exhause manifold, the bolt on the passanger side, rear most location was not there. Upon inspection today, it appears to be broken down in the block, about 1/4 inch down.

My plan is to soak it in slick-um for a few days, then hopefully it will come out with one of those reverse bit drills. Plan "B" is to drill it out and retap a size larger or so.

Or I hope some of you guys have a great idea on how to remove this little sucker. Then I think I'll install studs..........

And what exhaust gasket would you guys recomend? Copper? Aluminum? Fiber?

 

Use a dremel to get a good flat spot to start with and center punch the best you can. Start w/ an 1/8" bit and get a good straight pilot hole. Work your way up to the threads w/ ever larger bits then just peel the rest of the bolt out w/ an old pin punch ground at a sharp angle and light taps w/ a hammer. A sharp angle gives you an ellipse w/ the apex at the tip. Stuff a rag w/ grease rubbed around on it in the port before you start to catch the metal bits. Be patient and work out to the threads not into the threads and this works incredibly well. I've saved 40 year old pump packing glands doing this exact method.:v6:

 

If the bolt is broke a 1/4" down in the block, just pick a bit that just clears the threads for the centering of the starter hole and it should center it very close, then proceed as above with the smaller bit. Sometimes a transfer punch will also get it centered in this situation.

 

A good quality ez out after you drill can somtimes work great. Don't buy a cheap one, snap-on makes a really good set. Use lots of heat with it too.

 

I've had luck, (repeat "luck"), with drilling a small off centered hole on the bolt and using a centerpunch and a hammer to slowly rotate the bolt. drill the hole as close to the bolt's outer edge as possible. place the tip of the centerpunch into the hole and position the centerpunch so that when you hit the end of it, the bolt turns to unscrew. hit it lightly in small increments. not sure if my explanation is clear. of course this will only work if the bolt diameter is large enough and is not too sunken in. i think it was a 5/16" bolt that i did this on...

 

Thanks for all the suggestions. I think I'll turn the motor so the exhaust is up and start soaking the offending broken bolt in the magical elixer ATF/Acetone for a week or so. Then drimmel it flat and try to center punch and drill. I'll try an ez-out and see what happens........

 

Man, if you use an ez out, don't force it. If it won't start turning w/ light pressure, give it up. You don't want to deal w/ a broken ez out.:v6:

 

While I'm messing with this, is it that much better to convert to studs instead of keeping the bolts?

I'll be running Doug Thorley Try-Y's if that makes any difference. And any suggestions on a good, well sealing exhaust gasket would be cool.

 

You should check clearances to make sure nothing will interfere. Otherwise studs are the way to go. They give you something to hang the headers on and its way easier to change out gaskets.:v6:

 

Do not use a wrench with the ez out use a tap wrench so the force applied is even side to side. remember to alway use antiseize on the exhaust bolts unless they go to a water jacket, it makes removal much easier.

 

Mmm. If you pull the head, your local automotive machine shop will make quick work of removing the broken bolt.

The manifolds are supposed to be installed with no gasket. If there is no surface erosion from leaking exhaust, this works well with the iron manifolds. The fiber gaskets will blow out eventually, so I think your only choices with headers are copper or ... aluminum?

 

dont use alot of heat if any when using a easyout. it will ruin the easyout. DAHIK

 

I saw someone do this once:

Using a tig welder, he put a series of tacks on top of each other on the broken bolt. then he welded a bar on the tacks and applied some torch heat and the bolt came free. I'm not sure if this will work in you application though. mehh

 

Howard, thanks for the picts. Believe it or not, that is the first time I've seen exactly how the heli-coil works. Do you some some sort of threadlock when you twist in the heli-coil? Or does it thread in in such a way that it locks?

And no, I didn't look at the offending photos..............

 

don't use lok-tite or such. they dont generally come out once put in.

 

Any suggestion on where to get some exhaust studs? I've checked Bulltear and Summit. I googled the internet but didn't find what I thougth was right.

Ok I just found them on Summit. 80 bucks? You kidding me?

What about these? They are around $0.50 each. http://www.silver-seal.com/category/shop.engine_parts.enginefasteners.exhaustmanifoldstuds/ With nuts and everything around $1.00 a stud.................

Why such a big price diffference?

 

thats quite the engine hoist you have there howard Cant you rent those for like 10$ a day lol