Exhaust manifold bolt ... advice needed!

[johnmark]

I recently purchased a 1997 Ford Class A with a 460 engine. The exhaust manifold issues have been well documented and so I decided to put Banks headers and exhaust on it. All my manifold bolts seemed intact and so I started. The first one came out fairly easy but the infamous rear passenger bolt broke off. Only the head of the bolt broke so it is now flush with the manifold. Reading the horror stories of seized bolts and extraction nightmares and an upcoming trip in 3 weeks, I am thinking of just replacing my exhaust system but not the manifold at this point (which should lower the manifold temps). Since the bolt is flush and accessible I am wondering if it is possible to just weld a washer and nut on there and take it on my 3,000 mile trip. I have not had any leaks and the manifold looks good. I have attached a photo and would like to get some input on whether this is doable.



Another option I thought of was to just weld the hole shut since I will be replacing the manifold with headers after I get back from my trip anyway.

Any thoughts would be greatly appreciated! Thanks!

[indyzmike]

"Reply to update" That might work if the shank of the bolt is the right diameter and is soft enough steel to thread. If it is hard or too small, it won't work. If the bolt is soft but too small in diameter, you can find a smaller size, SAE or metric, that will result in full threads. I would still try heat to get the stud out. A propane torch is not hot enough. If you do heat the stud, don't try to turn it when it is real hot. The heat weakens the steel and you will break it off. Heat it hot, and let it cool for a while. Then you can put some force on it.

[Yankee_Clipper]

I found that an easy-out grabbed the stud and backed it out with a 3/8-drive socket. BTW - you cannot re-use the head bolts, and they are expensive as sin. Good luck! Be careful of your back-out torque, as the head is famous for cracking.
My experience changing the head is still archived here, I think.

[johnmark]

Update: The 8 bolts on the driver's side all came out clean. After almost 2 weeks of spraying 2-3 times a day (ATF/Acetone and PB Blaster) and hammering on the bolt that is stuck, it still won't come out. I am wondering if I should just leave it in and thread the stud and use it to secure the header with a washer and nut? Anyone ever done this? I think the Banks header flange is only 5/8" and I got plenty of stud left to get a washer and nut on it. Any thoughts would be appreciated. Thanks!

[RayChez]

hooligan wrote:
With enough bolt to grab, (welded nut or vicegrips) apply firm pressure and repeatedly hit the bolt straight on the end with a hammer. The shock helps break the threads loose. You may have to work back and forth before it comes out. (^^^^ Raychez)
FWIW I chased all the threads with a tap before putting new bolts/studs in...

That is the way to extract broken studs or cap screws. Good info and like you posted it does not hurt to run a tap down and clean out any foreign objects on the threads.

[hooligan]

With enough bolt to grab, (welded nut or vicegrips) apply firm pressure and repeatedly hit the bolt straight on the end with a hammer. The shock helps break the threads loose. You may have to work back and forth before it comes out. (^^^^ Raychez)
FWIW I chased all the threads with a tap before putting new bolts/studs in...

[RayChez]

Do not apply too much heat on the head to where it will melt anything. Why don't you try using the penetrating oil first and try to work it lose. If that does not work I would weld a nut to the stud and with a wrench work it back and forth. I am sure it will come out, but this thing of applying direct heat to the head, you got to know what you are doing. Too much heat can be damaging.

[Geocritter]

Also if you heat the stud you'll expand it, you want to expand the head around the stud. The head is a huge heat sink so you'll want to use an oxyacetylene torch to generate enough heat. Don't worry about flaming the residual ATF and PB blaster, what little is left that hasn't evaporated will promptly burn off. Still it's always good to have a fire extinguisher handy in case you catch something else on fire.

BTW if you don't have an oxyacetylene torch, Bernzomatic makes a relatively inexpensive hobbyist's torch that uses oxygen/Mapp gas that'll give you enough heat.

Steve

[cwit]

You should heat the head not the stud. If you heat the stud it may become to soft to turn out.

[Fleetwood99]

Great topic and thanks for your time to update the quest.

DJ

[johnmark]

Quick update: Thankfully the remaining seven bolts on the passenger side all came out clean. Used ATF/Acetone mix and also PB blaster. Couldn't find the AeroKroil locally. Thanks for all the tips!

I am thinking about heating the stud that broke off with a torch and then try to get it out with a pair of vise grip. Should I be concerned using the torch with so much ATF and PB blaster used? All I am trying to do is heat the stud. Wondering how flammable that stuff is?

[hooligan]

My 1990 Mh had the 460. Manifolds warped and sheared 3 bolts right at the head and eventually had a small exhaust leak. Had to use a RT angle drill and then a tap.
I replaced the manifolds, and Ford's "improved" manifold had slots for the bolt holes to allow the manifold to expand and contract without shearing the bolts. Did not use a gasket..
FWIW I vote for PB Blaster to soak the bolts..

[Bird_Freak]

I do this a couple of times a week in my business. Best I have found is AreoKroil sprayed a couple of times a day for 2 or 3 days. Weld a nut that will slip over the stud and back out with wrench while still hot.

[ThorResidencyNe]

This is EXACTLY what I feared would happen to me if I tackled my own Banks installation on my 460. So, just to be safe, I dropped my MH of at Banks and had them do it. The tech didn't say that any bolts broke off, but he did say it was alot of work.

Be sure to check the backside of the stock manifolds. My original ones looked fine on the outside but had 2" to 3" cracks on the backside between the exhaust ports. I didn't see these until the tech removed them from the engine. He said it was only a matter of time before they cracked completely though and melted my spark plug wires. Good luck!!

[johnmark]

Thanks everyone. I will tackle it sometime this week and will post an update soon.