Exhaust studs Snapped off . Any tips?

HI again , Im going to tackle the two Studs that snapped off on my block. They are still sticking out enough for me to grasp with some vice grips. I guess I have to put a propane torch to the stud to loosen the glue and work it out. Should I heat it up like crazy (red) I dont wanna screw this one up. later Xjers

 

Have you got any KROIL ? Apparently it would free up some change from a Jocks pocket.

 

You really don't want to heat the stud at all. What you want to heat is the boss it screws into on the head. The Aluminum expands faster than steel and it should let go.

When it's hot enough it'll turn easy.

 

Also, instead of using vise-grips, go purchase a stud extractor tool. There are a few different varieties and it'll make your job so much easier.

 

Be VERY careful if you use an extractor. I broke an extractor when trying to remove one of the master cylinder screws and it created a much bigger problem than I wanted. I know that the exhaust bolt is a lot bigger than the screw that I was working on, but it still pays to be more careful than I was...

 

heat, heat, and more heat. That doesn't mean cut the cylinder in half with a torch. but I heated mine for at least 10 minutes with a propane torch before it came out. Micarl is right, dont heat the stud, you don't want it to expand, though you can heat it really hot, then let it cool several times, and sometimes that will loosen it up. You are lucky it didn't break off flush. a normal propane torch won't get hot enough to get it red or hurt anything.

 

If you've got enough room, I've heard that welding a nut onto the end was very helpful.

Mine snapped off flush with the surface of the head. Any suggestions? I'm looking at just taking it to a machine shop (they said they do this stuff all the time, $60/hr).

 

well Ill give it a go now . I hope the engine does not explode . ..I joke . . thanks for the input once again .

 

Take the tank off and set it well away just to be sure.

 

If you are going to use heat, put your grips in the freezer overnight, you need the bigest heat differential possible.

 

Its.minus 36 outside.and the tank is already off outside.

 

Heat the area as much as possible without damage... then take a candle or crayon and touch it to the junction of bolt and head.... it will suck the wax into the threads much like sweating copper pipes... let it cool, repeat twice making sure that it cools to the touch between waxings.. the heat cool cycle plus the lubrication provided by the wax has never failed me yet...

 

Seriously Boomer? Having a similar stud problem, I was afraid to tackle it and hoping someone had a brilliant idea. Yours seems quite brilliant. OK, from whence did this good idea come? Your brain, stolen idea, what?

 

I've heard of that before from and old school machinist. The guy worked for an engine machine shop. I guess old school works

 

would that crayon trick work on an exhaust stud that's broken below the surface of the head?

any tips for that one? PO solved it by jury rigging a piece of bent sheet metal and some well positioned bolts around the frame attached to a working stud.

 

I stole that method from my first boss... an old master who'd gotten his start building pontiac gto's back in the sixties. He was amazing. It seems that the repeated heat/cool cycle makes a huge difference, and three times is the magic number. Lubrication from the wax makes it so that i've turned the fastener out with my fingers more than once if they weren't in a blind hole..

Moon, It works without regard to the stud's length AS LONG AS you can get the wax onto the area where the fastener and housing meet. In other words, if you give the threads an opportunity to suck up the wax, capillary action reigns supreme and they will. *note... remember that the wax will follow the heat.... so put the heat where you want the wax.

 

money thx!

 

about the welding a nut on the stud... if you are able to get it to a good welder, they can use a special welding rod made for it. basically, they'll thread a nut on all the way and weld the stud to it using the special welding rod. The rod has a flux on it that will cool around the steel faster than the steel itself. this causes somewhat of a straw to form. while the steel is a near liquid, it expands and will travel up the "straw" slightly. as the steel cools it will contract and solidify. since some of the steel is still in the "straw", it is no longer in the threaded hole for your stud. It's not much, but i does cause the stud to shrink and you can put a wrench on it after and it'll turn right out.

 

Thanks guys ! The deed is done. It took 15 min to get them out and replace them. Just want to add to this. Be careful of the valve gasket with the flame.

 

So did you use the wax method or just heat?

 

I used the Wax method , With a propane torch , and vise grips. Thanks Boomerkc! as well as all other contributers.

 

You're welcome, jonny! The reason I love this method so much is that I can use it even if I'm not near my oxy/acetylene rig.... especially before I owned one!!! I've used crayons, candles, and even a scratch repair stick for furniture to get the wax.... yes, I'm a scrounger!!!!! (one of my pet peeves is a repair method that requires expensive supplies and complicated techniques.... :twisted: here's to the old school!) I'm glad it worked for ya...

 

Heating the fragment is a waste of time.
The fragment is seized within a very-large heat sync.
The heat applied to the fragment gets pulled-away and dissipated.

The candle / crayon / wax treatment is a good idea.
In earlier Posts I have recommended using Soldering Flux.
Soldering Flux will do the trick; too.

 

Man I'm glad you guys are here, cause mine snapped on me and i and if could kick myself in the @$$ I would've. Thinking i was screwed cause i couldn't see any threads going into the head. I used the candle wax trick buy clamping vice grips onto the snapped of stud then heating up the head for a good 1 min, while heating the head i touched the wax as close i could to the head on the snapped off stud without burning myself.Then let it cool. Did this twice and gave a twist on the vise grips and she came out no problemo!. Thanks again guys.

 

Since it sounds like the studs are a major problem would it seem reasonable to take the time to heat/wax before you try to remove them the first time? What about the studs on the intake side??

 

The Manifold Cap Screws and Exhaust Pipe Studs are SOFT STEEL. Not a quality piece of Hardware at all.

Once the Manifold Side Cape Screws are SEIZED ... they usually don't come loose or out without snapping off. That the Cap Screw is so soft ... it will "FEEL" like it is turning. It is. It's twisting, though ... NOT turning.

The Exhaust Side Nutus will seize on the Studs.
The NUTS are easy to remove.
CUT the NUT on a bias ... practically right through ... then, apply a Chisel to the incision and break the Nut off the Stud.
Run a Die or a Thread Chaser on to the threaded portion to "Re-new" the threading.

Partially seized Cap Screws MIGHT be extracted.
Fully seized one's aren't coming-out and cause most people to begin a NIGHTMARE of fighting a losing Battle.

The Number-1 -- Most Cost and Labor-saving Solution is:
Remove the Head.
Bring Head to Machine Shop for:
a) Drill & Tap
b) EDM Controlled Arc "Burning-Out" of the Broken-off remnant.

In either case:
The Head will be returned to you with the Manifold and Exhaust Stud Holes
"Cleaned and Re-Tapped"

Put the thing together and USE a Quality ANTI-SEIZE Compound and you'll NEVER be in this position ... again!

 

All eight of the exhaust manifold nuts on my parts bike came off after squirting with Kroil. I then squirted the header pipes where they attach to the head. Two of the headers fell out of the head without touching them.

 

It's nice to hear that somebody caught a break!

It ain't that easy for most folks.
Some ... wind up behind the Eight Ball.

 

Newest and best tool in my toolbox? Birthday candles.

boomerkc, I bow to your superior skill set! Your Master GTO builder truly was a genius, as were you for knowing a Good Idea when you saw it. My exhaust stud was broken off below the head and I thought there was less than no hope. Rick's advice seemed the best hope, but far beyond what I really wanted to do. I just hate to tear down what works well. Plus "stubborn as a mule" has been used in describing my personality.

Went to the local supply house and bought a high quality reverse-twist 1/8" drill bit and a new e-z out. Then I applied the torch and wax method as you described. That drill bit cut into the stud like it was butter and I had to be careful because the aluminum head is so soft and space in my little shed so tight, that a slip could have severely damaged the head.

After a few stiff taps on the e-z out and a 4" adjustable wrench, that stud wound out slick as anything I have ever seen. The entire job, including re-installing the head pipe was about 30 minutes.

Domo origato, boomer-sama.

Snow is almost gone - nearly time to ride!