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I purchased a header from OpelGTSource and I have the intake manifold off, the coolant intake body off, and everything out of the way but I have a big problem :)

The darn head pipe I couldn't get off the exhaust manifold as the heads either didn't move, stripped, or popped off. So now there isn't enough room to tilt and pull it out.

I have about 2 ft of pipe off the exhaust manifold to deal with.

The manifold is mega thick and surprising doesn't break or cut easy :)

I thought about buying a good Reciprocating Saw or something...

ideas...
 

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I've never had to remove that head pipe flange from the down pipe, but since I picked up a new OGTS shorty header this week, I see the instructions state to give those down flange bolts a good soaking for several days with PB Blaster or similar, before giving it a go.


I'd think someone will come along shortly with some real-life experiences that might better help you, but I'll take a stab at this:

1. If you can access the 6 bolts on the underside of the flange, a combination of using either a sharp chisel and hammer, grinder or one of those small Fein style electric oscillating tool with a metal cutting blade could cut those bolt heads off (Harbor Freight sells a similar tool along with the metal cutting blades)


2 If you can't access the 6 bolts, a reciprocating saw, used to cut the down pipe up high near the flange, will do it as well. Then it's just a matter of either replacing the downpipe with a new one (if we are talking shorty header) or taking the cut downpipe to a muffler shop to be welded back into one piece (make a mark at one area of the cut, both sides of the cut to realign the cut pipe into it's proper orientation).

Check on the availability of a new down pipe just as a back up plan

Good luck, let us know how it works out for you
 

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I purchased a header from OpelGTSource and I have the intake manifold off, the coolant intake body off, and everything out of the way but I have a big problem :)

The darn head pipe I couldn't get off the exhaust manifold as the heads either didn't move, stripped, or popped off. So now there isn't enough room to tilt and pull it out.

I have about 2 ft of pipe off the exhaust manifold to deal with.

The manifold is mega thick and surprising doesn't break or cut easy :)

I thought about buying a good Reciprocating Saw or something...

ideas...
Since you are not going to be using your exhaust manifold again ... increase the size of your breaker bar :) and keep un-screwing the six bolts. Hopefully they heads will snap off and you can then get things seperated!

Call us if you need additional help :)
 

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Opeler
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I purchased a header from Opel GT Source and I have the intake manifold off, the coolant intake body off, and everything out of the way,
but I have a big problem :)

The darn head pipe. I couldn't get off the exhaust manifold, as the heads either didn't move, stripped, or popped off.
So now there isn't enough room to tilt and pull it out.

<snip>

ideas...
Do you purchase Shorty Header or Long Tube? Do you or friend have air compressor?
Try 1/2" (.500") 6-point hex socket vs 13 mm (.512"). 1/2" should be a little tighter on hex bolts.
Not sure if you can fit 4.5" cutoff wheel (angle grinder) to hack old exhaust manifold or use smaller,
high speed cutoff.
 

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I just replaced the stock with a Sprint, very similar to the Shorty header install, I was going to use the long tube header but decided against it for noise reduction reasons mostly. My plan was to cut the exhaust pipe using whatever, a sawzall or grinder. I attached a picture courtesy of Charlie1966 who recently installed the new stainless header to give you an idea where the cut should be made if it’s the long tube header. If it’s the “Shorty” keep working on the 6 bolts if you’re trying to save the exhaust, I use a short swivel with whatever socket extensions are called for most of mine snapped off, after the all do (hopefully) the bottom flange isn’t threaded so it should pry apart. HTH
 

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I seem to remember Rally Bob doing a thread on this sometime back, had some good idea's about how to put it all back together in a way that would make it a bit more easy to take apart the next time.
 

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I seem to remember Rally Bob doing a thread on this sometime back, had some good idea's about how to put it all back together in a way that would make it a bit more easy to take apart the next time.
Some have studded the exhaust manifold. I much prefer using SS bolts. I find it much easier to start a bolt than to try to start a nut on a stud.

Harold
 

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Some have studded the exhaust manifold. I much prefer using SS bolts. I find it much easier to start a bolt than to try to start a nut on a stud.

Harold
This worked very well for me once it was all separated and I put everything back together. Jarrell
 

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Some have studded the exhaust manifold. I much prefer using SS bolts. I find it much easier to start a bolt than to try to start a nut on a stud.

Harold


Mum... Header and Manifold Bolts some are S.S. some are Zinc some are Black-oxide,,, I noted That there some kind oF
"" Heatsink,,, Or Expansion of the header or Sprint Manifold Heats and cools down,,,, expansion that being built up

I bolted up my new 2" S.S Head Pipe to Cast Sprint Manifold torqued to required 15 Foot lbs etc...
Using New Stainless Steel Hex Bolts and washers

Then first trip to Carlisle with new exhaust... all but one manifold bolts had loosened and came out.. while driving the GT.. fell out, dropped out, missing. Boy, O Boy, was that LOUD! ....That really sucked that day trying find Metric bolts to rebolt exhaust... while on the road in Pennsylvania .. I was so lucky to find a small VW shop on a Sunday that was open... (owner was working on his own VW) and was my Hero, letting me use his shop ..his half size car-lift outside..on side of the road. "" The Guy Even gave me the metric bolts too! ... wouldn't take a dime either.. Nicest Biker/VW Dude, was just happy to get back on the road.. Happened with Jeff, and his Gold GT. Photos Attached...LOL Am crawling on dirt after Carlisle LOL Gotta it fix :veryhappy

So Here This location "" No Stainless Steel Bolts,, They don't heat sink properly"" use Black-oxide Bolts
Also if you snap a Stainless steel bolt you my as well toss it out.. very, very hard to remove




...Black-oxide bolts and to Use Allen key type.....SocketCap Head Machine Screws,, and flex socket.. 18' 3/8 extenision
plug the machine screws in to socket w/extension... and thread by hand etc,etc ... make for easy work.. setup

I think if you use a Torque Wrench on the 6 head pipe bolts with "" Every time"" you'll never snap ahead pipe bolt
most people "" Over tighten them"" and I think that's mostly why they snap Just My Honest opinion

I recommend Re-Torque the header..head pipe bolts(6) after the Road Test,, make sure bolts have not loosen from heat
 

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So Here This location "" No Stainless Steel Bolts,, They don't heat sink properly"" use Black-oxide Bolts
Also if you snap a Stainless steel bolt you my as well toss it out.. very, very hard to remove...Black-oxide bolts and to Use Allen key type.....SocketCap Head Machine Screws,, and flex socket.. 18' 3/8 extenision
plug the machine screws in to socket w/extension... and thread by hand etc,etc ... make for easy work.. setup

I think if you use a Torque Wrench on the 6 head pipe bolts with "" Every time"" you'll never snap ahead pipe bolt
most people "" Over tighten them"" and I think that's mostly why they snap Just My Honest opinion

I recommend Re-Torque the header..head pipe bolts(6) after the first Teat ride,, make sure bolts have not loosen from heat
May as well change mine out this Winter while it's in the shop, :sigh:Jarrell
 
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Mum... Header and Manifold Bolts some are S.S. some are Zinc some are Black-oxide,,, I noted That there some kind oF
"" Heatsink,,, Or Expansion of the header or Sprint Manifold Heats and cools down,,,, expansion that being built up

I bolted up my new 2" S.S Head Pipe to Cast Sprint Manifold torqued to required 15 Foot lbs etc...
Using New Stainless Steel Hex Bolts and washers

Then first trip to Carlisle with new exhaust... all but one manifold bolts had loosen and came out.. while driving the GT.. Fell out drop out missing. Boy O Boy Was that LOUD....That really sucked that day trying find Metric bolt to rebolt exhaust... while on the road in Pennsylvania .. I was So Lucky to find a small VW shop on a Sunday that was open... ( owner working on his own VW) and was a Hero. in letting me use his Shop ..his half size car lift outside..on side of road. "" The Guy Even gave me the metric bolts too,,, wouldn't take a dime either.. Nicest Biker/ VW Dude, was just happy to get back on the road.. Happen with Jeff,,and his GoldGT Photo's Attach...LOL Am crawling on dirt after Carlisle LOL Gotta it fix :veryhappy

So Here This location "" No Stainless Steel Bolts,, They don't heat sink properly"" use Black-oxide Bolts
Also if you snap a Stainless steel bolt you my as well toss it out.. very, very hard to remove




...Black-oxide bolts and to Use Allen key type.....SocketCap Head Machine Screws,, and flex socket.. 18' 3/8 extenision
plug the machine screws in to socket w/extension... and thread by hand etc,etc ... make for easy work.. setup

I think if you use a Torque Wrench on the 6 head pipe bolts with "" Every time"" you'll never snap ahead pipe bolt
most people "" Over tighten them"" and I think that's mostly why they snap Just My Honest opinion

I recommend Re-Torque the header..head pipe bolts(6) after the first Teat ride,, make sure bolts have not loosen from heat
Use anti-sieze with stainless, or at least some loctite, or you may never be able to remove those bolts. Stainless is stainless because the oxide that forms on it is very thin. When you bolt stainless together much of that oxide is rubbed off and does not reform at the mating surfaces, so they basically weld themselves together. You may have had that experience with plastic pipe. Unless you use sealing tape or paste you often can't tighten them sufficiently that they don't leak.
 

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RunOpel
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That is certainly a huge pain in the royal butt :yup: Very tight space to work in. I had the same issue and I just used a reciprocating saw and cut the pipe below the bolts. Easy then to pull out from the top. In my case, I was going to replace the entire exhaust. But it was way easier then trying to remove in place. Once I got it on the bench, way easier to remove the bolts :yup:
 
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Just Some Dude in Jersey
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It sounds like you bought the new shorty header and are trying to get the old headpipe off of the old manifold and reuse it on the new shorty header.

I suggest replacing the headpipe also. Start off new, leave the 50 year old stuff behind. Now the problem is much easier. Chop, saw, nuke that old stuff out of there any ole way you can. Then put your spiffy new stuff in with ease.

The cast iron of our manifolds is actually pretty easy to cut, if need be. If you decide to junk the old manifold and headpipe, then you only need to slice off the headpipe somewhere below the coupling and you can jiggle all that junk outta there.

As said, check with OGTS for availability of a new headpipe before slicing and dicing.

:veryhappy
 

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https://www.opelgt.com/forums/opel-gt-source/109745-big-shorty-back.html#post1421831
Now, what Opel GT Owners need is two (2) piece enhanced, exhaust head pipe.
Two piece design would allow cost effective shipping. Hope that they are working on it?

https://opelgtsource.com/search/2975/details
Car type: OPEL GT Category: Exhaust Head Pipe, Opel GT 1.9L
Part: 10004 Price: $149.00 Description:
Head pipe, is original-style exhaust pipe that connects from the bottom of the exhaust manifold to the front muffler.
Installs using part #10009 gasket and set of part #10011 bolts.


Heard random complaints regarding stainless steel muffler/ resonator exhaust kit.
Picture suggest that maybe newer design might be improved?
https://opelgtsource.com/search/3284/details
 

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If trying to save the head pipe, usually all I have been able to do is get 6 point sockets on and break the heads. PB Blaster helps if you are trying to save the manifold.

The 2 middle ones are the issue, and require 3/8" 6 point sockets and a short swivel extension, or 3" extension and universal joint, to get to the back-middle one.
 

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Detritus Maximus
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If you don't mind breaking the bolt heads off, but they are rusty, crusty, slightly rounded, you can try a combination of 1/2" or 13mm short sockets in 6 and 12 point styles to see what will seat snug on the bolt. If everything all those sockets are a loose fit, you might have luck with a 12mm. Also, if the socket seems snug, but still slips off, try tightening rather than loosening. The flats will start to round off in the direction you are trying to turn the bolt, but the socket may grab better going the other way. I have often broken bolts loose by tightening just enough to feel movement, then loosen them.

I got tired of drilling out broken bolts so I replace them with studs and use brass nuts (beware! strip a brass nut and it just turns on the stud, you will have to cut it off with a dremel, but at least you can cut it). The steel hardware will seize in the manifold. The center bolts are blind, but the outer four go all the way thru the flange and are exposed on top so water and stuff gets in causing corrosion on the end of the bolt. The blue loctite idea is good, but make sure the exposed ends are covered as well.
 
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Use anti-sieze with stainless, or at least some loctite, or you may never be able to remove those bolts. Stainless is stainless because the oxide that forms on it is very thin. When you bolt stainless together much of that oxide is rubbed off and does not reform at the mating surfaces, so they basically weld themselves together. You may have had that experience with plastic pipe. Unless you use sealing tape or paste you often can't tighten them sufficiently that they don't leak.
Good advice Mike on the anti-seize when using stainless bolts or nuts. Most folks don't know this. I have replaced over 120 (one hundred and twenty!) various Opel bolts with a stainless bolt kit I bought, plus a bunch of nuts & bolts that I bought (another hundred or two) separately. Whenever possible, i coated the threads with either anti-seize or Lok-Tite. For different reasons, of course, and either help coat the threads to prevent "galling", which is the mechanism that stainless fasteners can suffer when connected to ferrous threads. I don't know that stainless-to-stainless is a similar problem, but using a thread coating can't hurt.

As for the exhaust manifold-to-down-comer bolts, I almost always drill out the 6 lower manifold flange bolt holes and Heli-Coil them w/ stainless thread repair coils. I contemplated using stainless studs with copper nuts (almost totally eliminates any future issue with seized bolts or nuts, and is a common technique for exhaust fasteners). But I decided on stainless bolts (to match the stainless Heli-Coils) with Kopper-Kote anti-seize. It is much easier to start a bolt than a nut on a stud that is tucked up in that tight space, and the inside down-comer holes are slotted to allow the down-comer to hang off while the other bolts are started. Possible with studs, but trickier.

The REALLY tricky part is to get that little support bracket that attaches to the rear outside flange bolt and to the block at the front M10 bolt on the transmission bracket. One lesson learned (I just did this yesterday) was to start ALL the flange bolts, and then to tighten the rear inside bolt fully BEFORE the M10 bolt on the bracket is even installed into the block. The bracket-to-block bolt head (not to mention the bracket) prevents access to the rear inside bolt. THEN the bracket is bolted to the flange, and the remaining bolts tightened up.

HTH
 
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