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View Full Version : Avanti broken exhaust bolt patched, now polishing



sbca96
08-28-2006, 02:13 AM
UPDATES AT LAST POST

OK, I think that my Avanti just doesnt WANT to go to the show, could
it be shy? I dont know. Never turns red during picture taking.....

I drove the Avanti to work on Friday, getting off the freeway, it was
pretty obvious that something had broken. I had a decent exhaust leak
that wasnt that bad before. Today I jacked up the car, and found that
the gaskets on BOTH head pipes were GONE, toast, blown out. The pass
side I had replaced a cracked manifold years ago, so it came apart in
the normal easy way. The drivers side has never been touched while I
have had the car, and as you may have guessed, didnt come apart that
easily. The first problem was one of the lower bolts broke off. Then
I removed the booster to get to the manifold to head bolts. The front
two came off easily, but the middle two, and 5th bolt back had rusted
away to a 14 mm head size. The 6th bolt had become a 1/2 head size.
I found out that you can get to these from the wheel well easily. It
turned out, however, that the 6th bolt was broken YEARS ago, & while
trying to get the bolt loose (the head and broken off part was still
in the manifold) I broke the bolt AGAIN (yeah, no joke) because the
shaft was rusted into the manifold hole!! After I got the manifold
out of the car, I had to use a 3 pound sledge to knock what was left
of the bolt shaft out of the hole! Rust is amazing. So I have a bolt
broken off in the farthest back exhaust bolt hole in the head. I dont
think that I can get in there with a drill, and pulling the head at
this point is out of the question. I am thinking that with the 5th
bolt in there, it will be "good enough" to get road worthy again. Is
there any other exhaust manifold gaskets available besides the steel
ones? I think that a coated gasket will increase my chances of not
having a leak anytime soon (with 5 bolts).

Second question ... any tips on getting that lower broken off bolt out
of the exhaust manifold? If the guys at my work cant do it, I think I
will jet up to the Hawk up on the hill, and pull the manifold off it.

Tom

klifton1
08-28-2006, 08:59 AM
With the manifold off. They are soft, dill and replace both of them.
Klif

55 Speedster
42 Champ Coupe

sbca96
08-28-2006, 12:37 PM
Oh .. I am going to drill and replace both of the studs in the exhaust
manifold, but perhaps my question was confusing since it was a bit long
winded. The farthest back bolt in the HEAD broke off, the one behind
the steering column. Anyone have any tricks for getting to that one
with the head on the car??[B)]

Tom

N8N
08-28-2006, 12:44 PM
You know what you have to do... pull the head and drill the bolts out that way.

As for the manifold, I have about a 50% success rate with getting those studs out; the most reliable way I have found to do it is to grind the end of the stud flat (assuming it is sticking out a little) and then just drill it and retap. If you screw it up just use a Helicoil (with red loctite to hold the Helicoil in the manifold.) Worst case NOS manifolds are available and cheap. Might as well set up an electrolytic deruster (unless you have a blast cabinet) and put some manifold paint on before reassembly. I've heard that someone with skill with a cutting torch can "blow" the stud out of the manifold hole, but the one time I tried that I just ended up melting a piece of the manifold. I guess I need more practice.

Fel-Pro (I think?) makes the composition style exhaust gaskets for both the head and the downpipe. Some people like the metal gaskets better though. I'd check the manifold flanges with a straightedge; I've found some manifolds are so far out of true that they will blow a gasket almost immediately, only fix is to pull the studs and have them milled, or else just replace with NOS. Need I say that you should use lots of anti-seize on reassembly? SI sells "manifold repair kits" with the downpipe gaskets, studs, brass nuts, and washers - might as well order one of those. And if you can get some good stainless bolts for the manifold to head joint, I am kind of partial to those as well (with lots of anti seize)

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

N8N
08-28-2006, 12:48 PM
Forgot to mention, but you were going to do this anyway (right?) chase all the manifold bolt holes in the head with a bottoming tap before reassembly; it's the only way to ensure that you get the specified clamping force when you torque 'em up.

good luck,

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

gordr
08-28-2006, 01:53 PM
quote:Originally posted by sbca96

OK, I think that my Avanti just doesnt WANT to go to the show, could
it be shy? I dont know. Never turns red during picture taking.....

I drove the Avanti to work on Friday, getting off the freeway, it was
pretty obvious that something had broken. I had a decent exhaust leak
that wasnt that bad before. Today I jacked up the car, and found that
the gaskets on BOTH head pipes were GONE, toast, blown out. The pass
side I had replaced a cracked manifold years ago, so it came apart in
the normal easy way. The drivers side has never been touched while I
have had the car, and as you may have guessed, didnt come apart that
easily. The first problem was one of the lower bolts broke off. Then
I removed the booster to get to the manifold to head bolts. The front
two came off easily, but the middle two, and 5th bolt back had rusted
away to a 14 mm head size. The 6th bolt had become a 1/2 head size.
I found out that you can get to these from the wheel well easily. It
turned out, however, that the 6th bolt was broken YEARS ago, & while
trying to get the bolt loose (the head and broken off part was still
in the manifold) I broke the bolt AGAIN (yeah, no joke) because the
shaft was rusted into the manifold hole!! After I got the manifold
out of the car, I had to use a 3 pound sledge to knock what was left
of the bolt shaft out of the hole! Rust is amazing. So I have a bolt
broken off in the farthest back exhaust bolt hole in the head. I dont
think that I can get in there with a drill, and pulling the head at
this point is out of the question. I am thinking that with the 5th
bolt in there, it will be "good enough" to get road worthy again. Is
there any other exhaust manifold gaskets available besides the steel
ones? I think that a coated gasket will increase my chances of not
having a leak anytime soon (with 5 bolts).

Second question ... any tips on getting that lower broken off bolt out
of the exhaust manifold? If the guys at my work cant do it, I think I
will jet up to the Hawk up on the hill, and pull the manifold off it.

Tom



Tom,

I have had good luck using a MIG welder to build up a little blob on the end of the broken bolt. Then take a piece of scrap steel, like 1/8" by 1" band iron, drill a hole in one end, set it over the blob, and MIG weld it. Makes a "handle" to move the bolt with.

Now the first time you do this, likely the blob will just break off; just lather and repeat.:D It may take 2, 3, or even 10 attempts, but eventually the combination of torque and heat soak WILL break down the rust bond between the head and the broken bolt. Persistence pays off! I repeat, I have had many more successes than failures using this stunt. Leaves good threads in the cast part, too. The MIG won't stick well to the cast, usually, so if you have a steady hand, you don't need to "mask" the part.

BTW, most Stude V8s I've torn down used stainless bolts to retain the exhaust manifolds.

Gord Richmond, within Weasel range of the Alberta Badlands

sbca96
08-28-2006, 02:04 PM
Unfortunately I dont know how to weld, and my source for welding isnt
too keen on attempting this for me. I will be doing the drill and tap
deal on the manifold. The broken bolt in the head will just have to
stay that way. I cant pull the head right now, besides I think that
will just open another can of worms that wont get resolved by Friday.

I know that the rear gasket will most likely blow out in a few hundred
miles, but that gets me to the show just fine! I ordered the exhaust
gaskets from SI in the thick composition style. I was just hoping if
someone had a trick for getting to that rear bolt, I would give it a
shot before putting things back together. I know its not the "right"
way to do it, but I dont want to miss the show over this.

I also ordered the center rubber front bumper cushion.

Thanks for the help! I am sure someone will benefit also from reading.

Tom

CHAMP
08-28-2006, 03:05 PM
I haven't looked at a Stude v/8 head recently but on a 390 ford that had your same problem Iwas able to rig a c-clamp to help hold the head and manifold together. the way your luck has been running you probably can't do that on a Stude. Another method I've used with some luck is to clean area and smear muffler-exhaust sealer on manifold-head area. I had one car that lasted over a year before it leaked again. These are kind of make-shift repairs but your running out of time and the sealer just might work for you. If you decide to try the sealer make sure you let it set up overnight before you start the engine.The stuff I used is called Qualco muffler-weld repair and sealer. This may seem shade-tree but if it gets you to the show and back it might be worth a try. BTW, I bought thatsealer at NAPA.:)

GARY H 2DR.SEDAN 48 STUDEBAKER CHAMPION NORTHEAST MD.

dclewallen
08-28-2006, 04:42 PM
I also recommend the welding method. Worked for me on an aluminum intake with two tries and also on two square headed oil passage plugs I asked about in another post with only one try. Theres always left handed drill bits but due to rust they most likely would not work,

Darryl C. Lewallen Clarkesville, Ga.

sbca96
08-28-2006, 05:15 PM
OK .. the exhaust manifold bolt is out. I must say this is the BEST
job I have ever done drilling out a bolt. The threads are virtually
undamaged! With these results, if I HAD a good access to the head, I
would try it there (I did a bolt in the SAME location on my 93 Camaro
Z28, that car has aluminum heads so the stakes are higher!). I just
dont think that I can get in there, so it will have to wait. I think
that with the 5 bolts, and the thick gaskets I ordered, it will be OK
for the show (which I might have failed to mention includes a cruise!).
I did such a good job of drilling on center, I got a couple threads
of the old bolt out the bottom! I will stop by Napa and pick up some
studs to put in, and the shop foreman here suggested BRASS nuts.[:I]

Studebaker International said they will ship my parts TODAY, and as I
mentioned I paid for "next day".[B)]

Tom

N8N
08-28-2006, 05:39 PM
Just for the record, the factory used brass nuts on the manifold studs, as well as on the carb studs. One of those thoughtful little things they did for us that sadly some mechanics don't seem to have appreciated over the years :(

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

sbca96
08-28-2006, 07:07 PM
Yah .. I seem to remember taking off an original one, and the nut fell
apart, leaving usable threads. I will see if I can get some.

On the passenger side I replaced the manifold years ago, & I just used
standard steel nuts, but I used anti-seize. It came apart fine.

Tom

Roscomacaw
08-28-2006, 09:19 PM
Brass fine thread nuts aren't that easy to find. I come to realize this a couple years ago when I was determined to have some for an exhaust system. I wound up having a fastener specialty place order me a box of 50. Lifetime supply, I'd guess. Cheaper that way tho.

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

N8N
08-28-2006, 11:13 PM
they're still sold as "manifold nuts" under the Pik-A-Nut brand, if you have a FLAPS that carries same.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

sbca96
08-29-2006, 02:30 AM
I got some from a Napa here, they are about a 1/2 thick though! I also
got some lock washers and regular washers. Chased the threads in the
head, after taking off the passenger side manifold, I found that the
front bolt is broken off too. I forgot that was broken, "temporarily"
put it together with the 5 bolts about 10 years ago!

I did such a good job drilling out the broken bolt in the manifold, I
wanted to post pictures! Usually when I do this, I am off center and
end up ruining half the threads, this came out nice! (BTW its the one
on the right) :

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_problems003a.jpg

Here is the bolt threads that came out the backside :

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_problems004a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_problems005a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_problems006a.jpg

Now I just need the thick gaskets from S.I. (should be here tomorrow)
& I can put it back together, wash the car, and get it in the garage!

Tom

Chicken Hawk
08-29-2006, 07:28 PM
Be sure to re-torque the bolts after you get it hot once and this may help the gasket to last a little longer. The composition type gaskets will usually compress a little more after they have been hot.

Ted

sbca96
08-29-2006, 08:00 PM
Good idea Ted .. thanks. I was also thinking of using a little bit of
Permatex gasket sealer on JUST the one with a single missing bolt. I
think this will help to hold it in place, & maybe give a little extra
sealing pressure. I figure it cant hurt. It will make it more of a
mess to clean later, but hopefully the next time I remove them I will
be rebuilding/replacing the engine.;)

Tom

sbca96
08-29-2006, 10:18 PM
Parts got here, not exactly what I consider "thick" gaskets, but they
should do the trick for a little while. Shipping was 57 bucks! Ouch!
I didnt think it would be that much, was quoted a "high" of 50. At
least it removes one day of worry. Going out now to button it up. I
hope it goes back together better then it came apart!!

Tom

sbca96
08-30-2006, 04:02 AM
Here's the nuts I bought at Napa part number RFD STN-112-X, $1.40 ea.

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_success001a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_success002a.jpg

Exhaust leak cured, sounds quieter, and better than it EVER has. The
popping is gone on deceleration - I hated that! Got the cars moved
around, the Avanti washed - and into the garage. After work tomorrow
I finish the polishing I started on friday.

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_success003a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/Avanti_success004a.jpg

Tom

Mike Van Veghten
08-30-2006, 03:11 PM
Ted is OK.....

It's good to see someone that really understands the little things like exhaust gaskets.

It's another one of those wives tales....that exhaust nuts/bolts JUST come loose.
They come loose because the gasket changes shape after a few heat cycles and needs retightening...just like most head gaskets. All these little gagets that keep the manifold or header nut/bolt from spinning....don't understand the problem...it's the gasket that starts the process...
OR...maybe they do and don't care, as long as they make a buck fixing a non-problem.

Another kudos to Ted...

Mike

p.s. good job of drilling that "stud" out Tom.

John Kirchhoff
08-31-2006, 12:34 PM
I just love broken off bolts! (I'm being facitious!) A good way to get a rusted on steel nut off of a steel stud without twisting off the stud is to get out the trusty old torch. Heat the nut up red hot and quench it until cool with water. The nut will loosen right up in nearly every case. This also works on those tiny little flare nuts on a brake line. Invairably the steel brake line is frozen to the nut and you twist it off when you remove the nut. Do the same thing but make sure you direct the heat more onto the nut than the line because the line will heat up a lot quicker. Quench it, wiggle it a bit and it'll back off without a problem. This method has never failed me. Just be careful when working around any fuel lines or rubber bushings or hoses. Use a piece of tin to protect those items if needed.