VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Exhaust Manifold Stud Replacement

Folks,

I need help again. Replacing the exhaust, everything came apart OK, except the last bolt holding the exhaust pipe to the exhaust manifold.

Yes, I broke off the stud. About half is left sticking out.

Any suggestions about how to remove and replace this thing would be greatly appreciated. Is it threaded, reverse threaded, pressed in there? I'm sure worried about breaking the manifold itself.

I do see that the Filling Station has them for sale.

Thanks,
JIm

Did you try heating the stud to a dull red with an acetylene torch first before removing?

:confused: :confused: :confused:

No, I haven't tried anything yet. Does the stud screw out?

I don't have an acetylene torch, would one of those propane ones work.

Lets see, torch the stud to dull red, grab it with vice grips and unscrew it.

Try to remove when still dull red, or let cool?

Hmmmm, open flame 4 inches from the carb. Better take off the maniford.

The studs thread in and have the standard thread direction. You can try propane but likely it will not heat it hot enough to breakdown the rust holding the stud in place. Heat to red and then clamp it with vice grip pliers. Otherwise you can drill it out and clean the threads with a tap. It takes lotsa care to drill one out without distroying the threads in the manifold. If you don't feel comfortable then let someone else handle the problem. It will be much cheaper in the long run.

the studs unscrew if you are lucky and there is enough stud left to get vicegrips on and heat the ear on the manifold hot probably have to get a friends acetylene rig or bring it down to the muffler shop they may tack a nut to the broken stud and heat and very careful loosen the stud the studs should have had brass nuts on them so that they can be installed or removed without freezing up especially with a little neversieze . if i were doing the job i would remove the manifold put it on the bench where you can see it and work on it more than likely the stud can break off at the bottom of the manifold and the drilling and tapp procedure takes place . i would replace both studs while i was doing it . you can buy the studs and nuts at most good parts stores . or fs . you will need manifold gaskets too . i have repaired several that people have tried to drill out on the engine and went crooked and had to put helicoils in the manifold to repair . good luck

Owning an acetylene torch outfit is probably one of the mandatory tools to own when working on old cars. Most, if not all, of the rusty bolts and nuts should be heated with an acetylene torch before removal.

Is an acetylene torch outfit the same as an acetylene welding outfit?

I definitely need to retire, and work in the garage more. Do you guys think old-car-itis would classify as a Social Security qualified disability?

"Is an acetylene torch outfit the same as an acetylene welding outfit?"

Yes!

"Do you guys think old-car-itis would classify as a Social Security qualified disability?"

No!

:eek: :eek: :eek:

You probably can use a MAPP gas torch and get the stud hot enough. It will take a while. Acetylene is by far the best. I agree that taking the manifold off and working on the bench is also the best method.

If you need to drill the broken stud out you can use the exhaust pipe clamp for a guide to start the drill. Place it on the good stud and allign it with the broken stud. Use a smaller drill. As I recall the stud is 3/8 X 16 so the tap drill would be 5/16. After drilling with the 5/16 drill you can probably pick the old threads of the stud out of the manifold. Good luck.

Some ideas:

http://yarchive.net/car/broken_bolt_remove.html

As long as you trust them, you can remove the manifold, take it to your local machine shop, and have them remove it for you.

Ok, I'm back at the exhaust pipe stud. Got new ones just in case I get lucky.

I've been using a oxy-Mapp torch and heating the studs up to dull red in place on the car.

Still can't bust them loose with the vice-grips. Right now they're soaking in pbblaster.

What do you guys think of stud removers? They are a socket that is supposed to grip the stud real well. Would they give me a better bite than the vice-grips?

Thanks,
Jim

Two hours later...

I pulled the manifolds. Luckily, none of those studs broke off.


Still can't get either one loose. Vice grips keep tearing away metal...

I had an epiphany-- PIPE WRENCH!

Got the broken one out. Then promptly broke the good one off inside the manifold. AAARRRGGGHHHH! Off to get some good punches and fresh drill bits.

After drilling, I still couldn't get it to budge. Was afraid I'd break the easyout as it was twisting a bit.

Took the manifold to http://www.brokentap.com/index.html

in Santa Ana, and they got it out using their fancy electical discharge machine. If you're in LA and need work like this done, give em a call. Quick turnaround (20 hours).

Now to put the manifolds back on, and fit the new exhaust system.

Cheers

Although this is an old thread, it is a good place to put this info.

While fooling around watching videos online yesterday, I ran across this guy with a good technique and excellent explanation for how he gets rusty exhaust manifold bolts out of a head: Easy-does-it rusty bolt removal process

Enjoy, Dean

Not manifolds but I will add something to this. Ever try to get the wood screws out of our old Chev wood? Stripped out the slot right away? I have found most times if you tightly hold the screw driver in place and tighten the screw first you can then work it back and forth and it will come out. So far for me the only ones that didn't come loose broke off in the wood and the head fell free.

I took my exhaust manifold to a machine shop that was already performing other work on the engine for me. The stud had been sheared off and rusted for so long, it looked like it became one with the manifold. I have extractors and tons of drill bits, however these manifold castings are delicate and hard to find. I didn't was to take the risk of breaking the manifold flange off.