Help needed...broken exhaust manifold stud

[davester]

I am in the middle of replacing the leaking donuts on my manifold to exhaust pipe connection and all was going well until "SNAP" a stud broke off. I've got about 1/2" protruding I have extra studs but I'm wondering how best to get the old stud out of there. I would prefer NOT to have to remove the carbs and manifolds because I don't have a manifold gasket and don't want to wait days for one to arrive.

Any advice on easy peasy ways to get that stud out? I've slathered liquid wrench on but it doesn't seem like it wants to budge. Should I get the torch out?

Also, which way up do the donuts go? There's a smooth metal side and a non-smooth side. I'm assuming that the smooth metal side goes up against the manifold.

 

[Grantura_MKI]

Do not use a torch! Best to remove the Manifolds and weld a nut on the 1/2 that is out of the head. This is the best option...may take awhile, but you will be better of than if you break off the stud flush with the head.

 

[davester]

I'm not sure what you mean. The stud I'm talking about is the one between the manifold and exhaust, not the one between manifold and head.

 

[DrEntropy]

That's the one D is talkin' about, too. Have you tried "Weasel P*ss" on it?

50/50: acetone/ATF mix, shake, apply top and bottom of stud. Repeat.

Should be able to get an intake gasket from NAPA, BTW.

 

[PAUL161]

Dave, To save yourself some grief, pull the manifolds, it's the only way to pull that stud. You can't even get a stud retractor in there with them on. If you don't have a stud retractor, I'd weld a nut on it as suggested. The heat from welding will help also. As Doc says, put a 50/50 mixture of atf and acetone on it and let it soak for a bit. Sometimes tapping on a frozen stud will help the mixture get in the threads more. JMHO. PJ

 

[Bob_s]

why not use heat?

 

[davester]

OK, After a bit of pointless futzing underneath the car I'm following Paul's advice and pulling the manifolds. I actually put everything back together (leaking badly) so that I can drive it around while waiting for the gaskets to arrive. Long gone are the days of zipping down to the parts store for routine parts. I did call NAPA and several other places and they all but laughed at me ("did you say it's a <span style="font-weight: bold"><span style="font-style: italic">seventy</span></span>-one"?)

 

[DrEntropy]

KounterKids. *sheesh* :wink:

Apparently we've got better access to NAPA inventory here. FelPro still makes 'em, we've no problem getting 'em. I prefer the Payen stuff but in a pinch, FelPro is fine for manifold gaskets.

 

[Grantura_MKI]

I find that most Napa counter-clowns are only as good as the part numbers that you supply FOR them. Using to old books in not hear of...if it is not in the computer then is does not exist.
Applying heat to a cast iron part is not advised as you are generally only able to heat a small area. This will make for "hot" spots in the casting...not a good thing.
Pauls advice? Just joking...I do not care where it came from as long as you are the winner in the end!

 

[Big6Mark]

Applying heat to a cast iron part like that will only flirt with the danger of it cracking.
Use the penetrating oil of your choice and try to twist it out.
I would not hesitate to cut it off flush and CAREFULLY drill it out. Start small and get it centered and slowly drill out larger and larger until you are at the i.d. of the threads and try to start a tap in the hole and cut out the remains of the broken stud.
Once you have removed the broken one and replaced it with new make sure you use brass nuts from now on. At least it won't rust on and you won't break the stud before you break the nut.
I have resorted to making replacement studs at the bottom of the exhaust manifold out of stainless and still using brass nuts. Had them on my Healey and have them on my MGC and in the heat riser studs on the intake manifold as well. Works great!

C Ya,
Mark

 

[Bob_s]

i'm not knocking anyones advice here for sure, but working as an automotive tech for 25+ yrs(mostly domestic,not british) i've heated many many exhaust manifolds with punky studs and never cracked one..worked with countless guys in the next bays doing it also, it's our first choice in dealing with it..don't heat the stud,heat around it and work it out slowly..taking the manifold off is a bonus,it'll take 10 min to get it out, tap and done..i know time is more of a factor in that environment and plays a huge part in the decisions, so it's jmho..bob

 

[Grantura_MKI]

I fully understand what you are saying, Bob. One big problem here that you are missing...we are dealing with Engish castings, not American. I truely believe that the English would chuck anything in a casting as a filler, just to make the item less expensive to produce. I remember "porting" a 100e motor one summer. I would come out to the shop the next day only to find that the block looked like it had been soaked in water over night! Second is that some of this bits are just plan getting more difficult to locate. I do understand your need for a speedy solution, but most likely you can ring the dealer, etc and have a replacement in a matter of hours.

 

[Silverghost]

I have to agree with Bob on this one. I snapped an exhaust manifold stud when I did my clutch r&r this summer. When I had the engine out, I used heat to get the broken stud out. I didn't need much and it came out easily. The new stud went in easily and I've been driving it ever since.

 

[Bob_s]

we definitely understand each other D. altho i did take a quick look at my wifes mg manifold, it's a from a 75 i believe and it looks hefty enough but looks just won't cut i'm sure. i sure would hate to put someone in a bind following my advice,taking into account my very limited british experience. the quality of the part( and i usually don't have to give that a second thought) and the experience of the guy wielding the torches does make a huge difference in what route to take..in the spridget forum jack laird spent 3 days and 16 drill bits drilling out 2 spring bolts while laying under his bugeye. that was a huge wake up call for me as i don't have the patience for that, but, i'm thinking i'd better develop a little, as i'm about to tackle the same job..i wish dave luck in removing his stud..bob

 

[PAUL161]

I think a misconception has formed here in this thread. No one in my mind is suggesting to heat the block! The suggestion is to heat the stud, only the stud! And, that will also happen if and when you weld a nut on it! Heating the stud expands it slightly and then it'll shrink when it cools. During this process it loosens the rust and crud that is gripping the threads. If that doesn't work for you, then I guess you'll just have to drill it out. PJ

 

[Steve_S]

It if won't budge, my method is to pull the manifold and drill it out. In the long run it's far easier and faster than soaking, heating, etc all day. I try oil and heat first of course, but only once or twice. The worst thing that can happen from drilling is you damage the threads, and in that case just put an insert in it. This isn't a high torque fitting, it only needs to hold the flange on.

To answer your other question, the metal side of the gasket goes down. Soft side up.