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Spitfire Help! Spitfire 1500 exhaust flange studs broken.

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guzzul

guzzul

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I am trying to replace the drive shaft u-joints on my 78 Spitfire, which means dropping the exhaust pipe. Of course the exhaust flange nuts were seriously rusted onto the studs, and all three have now sheared, leaving various amounts of stud remaining in the exhaust header flange. It looks like one of these was already broken, beause there was a bolt in it instead of a stud and nut. Its broken now too.

Any ideas on how to deal with this? I am hoping to be able to avoid taking the exhaust manifold off to get at these.

Thnx all.
 
Unfortunately, the only way to deal with this correctly is to remove the manifold. If there is enough of the stud protruding to grab with a pair of vise grips, you can heat the manifold cherry red around the stud, and turn it out.
If there isn't enough to hold, it will have to be drilled out and re-tapped.
I hate to be the bearer of bad news, but in the long run, this will be easier and faster than trying to deal with it in the car.
When you get around to re-assembling everything, use brass nuts on the studs. This will prevent them corroding onto the new studs.
Jeff
 
Thanks Jeff. There may be enough stud on all three to grab with vise grips. Are these studs threaded into the exhaust flange or just pressed in?

I was thinking (providing I can get them out) of just drilling the holes clean, and using a bolt and nut to re-fasten them. It would seem in the future if this happens again it would be way simpler to just twist off the nuts and push the bolt out. With studs you have to rely on anti-seize to keep the threads workable.

Ross
 
Ross, the studs thread into the flange. With the proper brass nuts, it isn't a problem to use the studs. But, a nut and bolt will probably work. However, I have seen this method used, and it seems that the nut usually loosens up, causing an exhaust leak. It also may be a fiddle to get a wrench on the bolt towards the engine block.
If you are going to try to heat the manifold while it's still installed, be careful around the fuel line, and have a fire extinguisher at hand.
Jeff
 
Thanks Jeff. I assume the technique is to heat the flange and not the stud. And try and get some expansion going.

I'm a little nevous about the fuel line, but its pretty far removed, and I don't see any leaks. I will try and sheild it somehow though, just to be safe.

I am presently trying to get some liquid wrench penetrating into the studs, and I will let that do whatever magic it can over the next day or so, then try to move them with vice grips. Worst case, I suppose, is pulling the manifold.

Thanks again.
Ross
 
Ross,first let me welcome you to our litlle corner of the nuthouse. I didn't realize it until now that you were new here. My apologies.
As far as pulling the manifold goes, it's no big deal at all. You can leave the carb and throttle cable attached, and just swing the intake out of the way. I suppose you still have the water lines running to the intake though.
Hmm. Hadn't thought about that. My Spit motors have all been race engines, with none of the extra stuff attached.
Maybe you'll get lucky with the penetrating oil.
Jeff
 
Yep - I just joined. I have been looking for this kind of forum, so delighted to be here.

Yes, I need to partially drain the coolant, disconnect the water hoses to the intake manifold, etc. Truthfully, my biggest concern about removing the manifold(s) is that I will wind up shearing off yet another stud (this time in the head).

I'm going to try with the liquid wrench. I'll post an update in a few days as to how successful (think positive) I was.

Cheers,
Ross
 
Re: Help! Spitfire 1500 exhaust flange studs broke

welcome aboard guzzul, this is a great place.

Good luck with your manifold troubles, bout the only thing i can add is, as Jeff said, in the end you will probably wish you just pulled the manifold off. much easier to deal with.


mark
 
Re: Help! Spitfire 1500 exhaust flange studs broke

/ubbthreads/images/graemlins/tongue.gifIf I were you, I'd remove the manifold. Pretty easy job. I don't think I'd be that concerned about snapping off the manifold bolts. They're not exposed to nearly as much crud as later on in the system. If it makes you feel any better, this is what happend to me a couple weeks ago. I'm swapping a 472 Cadillac motor into a friends hearse. Junkyard motor, just to get it up and running. Well, I notice that the rear most exhaust manifold bolt is broken. I check the otherside, same thing. So I figure, if I put it in the car this way, it will 100% undoubtably leak. So I opt to fix it, since the motor is already out. Well, being nice and gentle, using a torch, etc. I wind up breaking 7 of the 16 bolts off. Out of that, I managed to remove 3 of the 7 with heat and v-grips. Wound up having to drill and tap 4! Arrggghh! /ubbthreads/images/graemlins/nonod.gif
 
Re: Help! Spitfire 1500 exhaust flange studs broke

I had the same problem with my 67MKIII manifold. In my case the broken stud was so malable from heat and cool cycles that it wasn't strong enough to actually remove the stud from the exhaust flange. I used a MIG welder with SS wire to weld a large nut to the remaining stud to increase the torque to remove the stud. [The ss wire will not weld to the cast iron flange.] I used penetrating oil and heat also. I believe most exhaust shops have the capability to do this in case you don't have a welder.

Good luck
 
Re: Help! Spitfire 1500 exhaust flange studs broke

Ross,
Been there too. It's much easier with the manifold off. And PB Blaster is much better than Liquid Wrench. I'd build a little dam around the studs and soak em ffor a couple/few days then try the heat and vise grips. Worked for me. Good luck.
Steve
 
Re: Help! Spitfire 1500 exhaust flange studs broke

Welcome to the forum. Hate to start on a negative note but if you get those studs (stubs!) out with pentrating oil, moderate heat and vise grips you should run out and buy a lottery ticket 'cause you are one lucky guy.

Much easier to work on it out of the car -- I took mine to a local machine shop where they could get it way hot (almost flowing) to get 'em out. Just a few bucks and worth it to me.

No one has mentioned EZ-Out and that's good -- I would not be tempted to try anything like that on them because if one of tose gadgets breaks in there it is a real problem.
 
Re: Help! Spitfire 1500 exhaust flange studs broke

Thanks all. I think the jury is pretty clear on this...looks like I'm pulling the manifold.

I have been checking out the BL repair ops manual, and getting it apart seems ok, provided none of the manifold bolts shear I guess. As frankenstang notes, maybe these will be ok.

I have been dutifully soaking the studs (stubs) with Liquid Wrench, I'll give that at least one shot. If the manifold is coming off, I'm drilling these suckers out and using a bolt/nut for future.

Meanwhile, I started all this because I needed to drop the prop shaft and do my u-joints....
 
Re: Help! Spitfire 1500 exhaust flange studs broke

/ubbthreads/images/graemlins/tongue.gifHehe, happy thoughs, happy thoughts... /ubbthreads/images/graemlins/grin.gif
 
Re: Help! Spitfire 1500 exhaust flange studs broke

Welcome Guzzul....
Forum members get a discount on case lots of liquid wrench /ubbthreads/images/graemlins/crazy.gif
Wherabouts in "Canada"?
 
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