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Curve Crazy GT
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399 Posts
my GT recently started an exhaust leak and at first it was not that bad but now its way to much! So i jacked it up and looked under neith THERE ARE ONLY 2 BOLTS ON IT! i dont know what kinda bolts go in it? is the manifold supose to be studed? the 2 are just some bolts slid threw from the top and tightend witha lock nut. out of the 6 holes if it looked like this
O O O
O O O
looking up from the ground the first 2 closest to the block are the only ones with bolts. i spent about an hour tring to figure out how in the world to get the other 4 in with just a bolt and nut. and the only thing i could come up with is take off the intake and thats out of the question unless its the ONLY way to do it.

so all help is welcome on this uncool problem.

thanks
chris
 

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Curve Crazy GT
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399 Posts
Discussion Starter · #2 ·
oh jeese i went to look at it its the 2 holes furthest away from the block are the ones with bolts in them

sorry

thanks chris
 

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Member
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583 Posts
Exhaust flange bolts

Chris,

The bolts fit up from the bottom and should thread into the flange on the exhaust manifold. I believe that they are 8mm X 1.25 or 1.50 pitch. You can try a good hardware store or Home Depot/Lowe's. The length is about 25-30 or 1-1 1/4 inches.

The center bolts are you will not see the thread on the back side as they screw into the center of the flange. If there are no bolts visible on the end holes away from the block then they have vibrated out (unlikely) or been removed. As long as those and the center holes are clear, you should be able to put bolts in and tighten up the exhaust pipe.

Be careful, that manifold is cast iron and can break under pressure. The bolts are only torqued at about 30 ft/lbs.

Good luck,

Dave
 

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Curve Crazy GT
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399 Posts
Discussion Starter · #4 ·
thanks so does that mean that i should buy studs to put in the manifold or do i jsut a buy a bolt the same size as u said and just put them in?

thanks
chris
 

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Old Opeler
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5,564 Posts
8mm by 1.25mm pitch - standard ISO threads........ studs are better
 

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Pathologic Opeler
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1,960 Posts
manifold studs

this is what you need, oldopelguy fixed me up with these studs, they are great

page 3 parts ads on this site
 

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Curve Crazy GT
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399 Posts
Discussion Starter · #7 ·
thanks guys but now the question is how do i get them in! i have really no were put my hand in and i can even see teh middle 2 bolts from under the car

but im goin under there now to take a better look so any help is good


thanks
chris
 

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Pathologic Opeler
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1,960 Posts
long extension

a socket,eyeprotection, and a long extension. 5 were easy to access, one was hard for me. i think the one on a rear corner was hard, if i remeber correctly

as you work ..debris will fall in your face.

if you jack the car up, make sure you have a solid object thicker than your head and body between you and the car.


the first time i took mine out i had rusted bolts.. i cut it with a dremel (cut off disk) about 2 in behind the bolts, then i unbolted the carb and manifold from the engine and took it out the top in one piece. then i had access to replace the studs.oldopelguy taught me this, on this site.

i then put it back together, install thru the top of the engine bay.

then drove to a shop to weld the muffler pipe
 

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6,344 Posts
O.K. guys, I'm surprised no one said my favorite recording, so here goes: Chris make doggone sure your coat the threads on both ends with hi-temp anti-sieze compound, use a torque wrench to insert the studs, or, as has already been stated, you'll break the casting. To put the studs in the flange, put two nuts on the long end and tighten them against each other, then you can use a socket and torque wrench to put them in. Oh yeah, grade 8 or better studs or when you take the nuts off at a later date the studs will break off in the flange.
 

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Super Moderator
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5,923 Posts
coolchrisp said:
thanks guys but now the question is how do i get them in! i have really no were put my hand in and i can even see the middle 2 bolts from under the car
thanks chris
Even if the holes are intact, it is a PIA to get the bolts back in place. I usually use a long extension with a wobble end, and a deep'ish socket (not too deep, as the bolt can't be too long, at least for the middle holes). Then I just stick the bolt end that protrudes from the socket into the hole and pray. And finagle. And swear. And kick things.

Often the old bolts are broken off inside the manifold holes, or the threads get stripped. As you have seen, if the holes are stripped, you can back them up with a nut on the top on the outboard holes, but the inboard and centre holes require decent holes and threads.

If this is the case, as Dean has noted, you pretty much have to remove the manifolds (easiest to remove them as a pair and to not disturb the bolts that connect the intake to the exhaust manifold) and repair the holes. You might have to drill them out and install thread-repair coils or inserts.

I also bought two sets of those stainless steel studs and copper nuts, which I think will make installing the down pipe MUCH easier, and less troublesome to remove in the future.

HTH and good luck
 

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Premium Member
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1,802 Posts
helicoil

kwilford said:
you pretty much have to remove the manifolds and repair the holes. You might have to drill them out and install thread-repair coils or inserts.
If you have to remove the manifold to drill out any broken studs, I'd recommend using heli-coils or the like on every one of the holes. having the studs screw into a steel threads instead of the cast iron makes them a lot less likely to rust together in the future. Those copper, or even brass, nuts can't rust to the steel studs which makes getting them off in the future a lot easier. I actually prefer the ones designed for VW air-cooled motor exhaust flanges because they are the right thread but only 11mm heads, which allows for a mit more room with gettign the tools in there. Like these:
http://cgi.ebay.com/ebaymotors/VW-E...42610QQitemZ7997403041QQrdZ1QQsspagenameZWDVW
http://cgi.ebay.com/ebaymotors/VW-G...33634QQitemZ7949428849QQrdZ1QQsspagenameZWD1V
http://cgi.ebay.com/ebaymotors/VW-I...33634QQitemZ7944626790QQrdZ1QQsspagenameZWD1V
 

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Curve Crazy GT
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399 Posts
Discussion Starter · #12 ·
thanks to all ill probably be ordering those nuts off ebay there and as for the studs i may go down to the machine engine shop down the road and check if they got some high grade studs they recomend.

thanks to all of you again


chris
 

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Opeler
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224 Posts
where to cut?

so did you cut the exaust pipe ? then remove the head pipe from the exaust manifold after its out of the car? thats the only way I see to get it off the bolts are froze solid
 

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Curve Crazy GT
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399 Posts
Discussion Starter · #14 ·
Fortunatly when i did it i was able to bust teh bolts off so i jsut re moved the down pipe and re taped and put in new studs in . to break them u can try liquid wrench sprayum down once every hour for a few hours and tehn try and break them loose.
 

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Opeler
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224 Posts
I've been trying on and of for 2 days to get them out the exaust manifold is not going back on but i was hoping to reuse the head pipe .. but looks like it will have to be cut. Can the head pipe/flange be replicated by any exaust shop?
 

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Old Opeler
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5,564 Posts
Cut the Bolts!

If you want to save the head pipe and flange just cut the nuts with a cold chisel or drill the heads of the bolts off to let it come off. Would be quite pricey to get one made as it is a non-stock item that only fits Opels.......
If you do ever want to use the manifold again you are going to have to drill and remove the frozen bolts anyway.
Oh! You could try soaking the bolts in Coca-Cola ... I kid you not! The phosphoric acid in Coke removes the rust in a few days ....... try it!

Heat and candle wax can also work - have a look at this thread:

http://www.opelgt.com/forums/general-faqs/2744-stuck-bolt-frozen-thread.html?highlight=Coke
 

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Opeler
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847 Posts
kent said:
I've been trying on and of for 2 days to get them out the exaust manifold is not going back on but i was hoping to reuse the head pipe .. but looks like it will have to be cut. Can the head pipe/flange be replicated by any exaust shop?
If the bolts head pipe-to-manifold cap screws are original size, use a 1/2" six point socket (it's slightly smaller than 13mm) with whatever wobble or universal and long extensions needed to get to them, and you should be able to apply enough force to snap off the screw heads. Unless I'm working on one of my cars that I had apart already (and used stainless screws and anti-seize compound to reattach the head pipe), I just assume half of them will break no matter what. You have the best chance of getting the center ones out because they're in blind holes, but at least one of the others is guaranteed to break. If you don't plan to re-use the manifold, it's no problem. If you do, then you can spend an evening extracting broken screws.
 

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Living in the past
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2,340 Posts
Headpipe flange bolts

After you spray them down with nut-buster or some other penitrating oil take a brass drift and a hammer and put the end of the drift on the head of the bolt and smack the other end with the hammer, that will sometimes free it up some. do not use a 1/2 inch drive ratchet of impact gun to try to remove them. Use a 3/8 ratchet and when you feel the bolt break loose turn it out about two or three threads then reverse the ratchet and turn it back in, keep repeating this process until you get the bolt out. Takes awhile but is much easier than taking the manifolds off the side of the head and drilling and re-taping those bolt holes. If you have to cut the head pipe cut it behind where the two pipes go into one about 3 inches, then it will come out with the manifolds and the muffler shop can weld them back togather.
 

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Registered
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6,344 Posts
Another thing that works well is to heat the studs until they are red hot and use a pair of vise grips (and a leather glove) to back them out - saves the threads for new studs!:)
 

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Living in the past
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2,340 Posts
Manifold bolts

Be careful where you go poking a "smoke wrench" under an Opel, remember the fuel line is in that area and it is plastic and it will make you a crispy critter in a heartbeat.
 
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