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headpipe to manifold

getting ready to change out an engine and one place i can see that may be a problem is getting loose the headpipe to mainfold bolts without breaking them off. What are the odds I'll get them to loosen up vs. breaking off. If they do break off how huge a job is it to get them out?

Also, if I decide to just unbolt the manifolds at the engine and NOT take apart at the headpipe does this make the engine removal and replacement more of a headache? and if so how much???

Any help appreciated.

1973 GT
 

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Bosco, One type of "liquid wrench" I've found to be very useful is called "Rust Eater", I've used it almost exculsively for removing rusted nuts, bolts, and even the brake lines on the wheel cylinders. I would suggest you use it or a similar product on the exhaust nuts before attempting to loosen them. I had great luck with the above product when I disconnected the head pipe from the manifold when I pulled my engine, and on other parts that have been on the car since new. If you do break a stud off in the manifold, the choices are use vice grips if there is enough stud to grab onto it, drill the stud and use an easy-out, carefully, if you break the easy-out, it will be a bear to get out, or last option, take the manifold to an automotive machine shop. As for taking out the engine with the manifold removed and left in place, I don't know if there is enough room to drop the engine/tranny down without hanging up on the headpipe, but there might be enough room, I don't know. HTH.

Ron
 

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eh? 6 of 1, ...

I've removed the motor by leaving the manifolds in place a time or two, it really isn't that bad. It might require removing the distributer for clearance, but no big deal.

My favorite rust-eater is wintergreen oil. Works better than anything else I've ever tried, and leaves the motor minty fresh.

Once you get the head pipe apart, and I can't stress this too much, replace the nuts on the Opel with brass ones so you won't have this problem ever again. Even Autodrone has them on hand in the HELP section, but the ones you can order from BugStuff are better. Not only are the VW ones thicker for more contact, they are a much easier to get a wrench on 11mm instead of the 13 or 14mm of the stock and parts store replacements.
 

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Detritus Maximus
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I think you can drop the engine after separating the mainfolds from the head. The clearance needed for the transmission may be gained as the manifolds and head pipe will also drop down a bit.

My recommendation is to install studs in place of the head pipe to manifold bolts. Just make sure to use brass nuts (they won't seize on the studs, so you can remove them with no hassles).777
 

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Regardless of which hardware you use to put it all back together, I cannot over-emphasize getting and using some anti-sieze compound for all the nuts and bolts, except the internal engine bolts, including head bolts. They have to be torqued with clean threads. Another area for anti-sieze compound is the water pump bolts and the external engine hardware. Nothing is so maddening as to have a bolt snap almost flush with the surface, been there, done that, more than once, but on other folks cars, lesson learned a long time ago. Before a bolt or nut goes for the last time, it's coated.
Ron
 

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I'm sending this thread (if I can figure out how) to my son. I've got his Opel GT now (bought from the insurance company under salvage title) and he's got an 86 RX7.

He overheats the thing, and busts a hose. 30 minute fix at the most. But decides while he's at it to replace the thermostate that he just replaced six months ago.

Busted the thermostate hosing bolt. Busted the easy out bit. That was four weeks ago. Still using my mini-van.
 

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manifolds

I just pulled a motor and left the exhaust in place, wire the manifolds up out of the way and it shouldn't be a problem, then, if you want, take those bolts out. It will be much easier with the engine out of the way. Good luck.
 

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West Coast GT, About the only way to get the easy-out removed, actually there are two ways, is 1, get the broken easy-out tool from your friendly machinist, 2, get a very small carbide rotary file and a Dremel moto-tool. I've used both and neither one is easy. The carbide file and Dremel, worked the best for me, a busted water pump bolt on a 289 Ford. It took about 2 hours to grind the easy out and then drill and retap the hole, after I ground out most of the old bolt. HTH.

Ron
 
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