Broken exhaust bolt on 460 ci Ford engine. Help?

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Wallnut

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Several of you were kind enough to give me your opinion on the 460 Ford engine, and mentioned that a common problem was a broken bolt on the back right side of the exhaust manifold.  I checked mine out and discovered it was broken.  There is no evidence of external exhaust gas leaking - yet.

My question is what are my options?  Several mentioned installing headers - is that because the problem would happen again if the stock manifold was installed again?  If I do nothing, will it cause the head to warp, if not already warped?  Should I wait until I hear or see evidence of exhaust gas leaking?

The engine has 37,000 miles on it and is installed in a '98 Coachmen Catalina 301WB class A.  I just recently bought it and it runs great - got almost 10 mpg with it the first few times I have used it.  Engine runs cool.  Wish I had know about this before I bought the motorhome but I got a good deal on it so investing some more $ into it is an option I would consider.

As common as this is to Ford 460's, you would think that the mechs at Camping World would have caught it. "Buyer be ware!"

Thanks for your thoughts.

JR.
 
I have "heard" that's an expensive fix because the head must be removed to make room to drill out the old bolt.  If it's not leaking or making a bunch of noise, I'd leave it alone.  Mine also has the same issue, but you can only hear the "click" from the exhaust when you first start up.  Once the manifold warms, I suspect it tightens up and is fine.  Mine has been like this since 2003 and I've put over 50,000 miles on the rig since.
 
This is common problem with Class A motor homes and the F-53 chassis with the 460 engine. The manifold  warps at cylinders #4 & #8. The bolt breakage is caused by the warping of manifold itself, not the bolts. Not only that, but the cylinder head(s) have been known to crack at the above mentioned exhaust ports as well. I would recommend you have this repaired as soon as you can. Most of the time the mechanic only has to remove the exhaust manifold and work the bolt out. Usually it is just the head of the bolt that breaks off leaving enough of the bolt exposed, thus making it much easier to remove.


Jay T
 
I would reply, but it would take me hours!  Read through my saga on another RV forum...!

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24821700/srt/pa/pging/1/page/1

ryan
 
i had an 89 allegro and had 4 broken off, a good torch and i got a long drill bit and easy outted them out, just make sure you get them hot and they should come out, mine did
 
Many thanks - especially Ryan - that link was very informative.  The broken bolt on mine looks to me as if only the head of the bolt sheared off.  I can see the remainder of the bolt within the hole of the manifold so I may get lucky and be able to wrench it out after the manifold is removed.  I don't really know how to handle it from there as there are so many different opinions.  Resurface the head?  Resurface the manifold and the head?  Use a manifold gasket?  Mount the manifold without a gasket?  I guess I'll look for a shop here in Georgia where I live that is familiar with this.  It may not be as bad as I think if enough of the bolt is available to grab.  I have done similar repairs years ago to aircraft engines by filing a flat on the end of the stud and backing it out with a wrench.  Maybe I'll get lucky.

Thanks again everyone.

JR.
 
JR, Once you get the manifold off, hit the end of the stud, on the end, with a hammer a few times. That will help shake the stud loose from the rust. Then get out your favorite pair of vice grips and unscrew it. Make sure and use a Ford stud. Expensive but the best fastener for the job. I have a few dozen in a box from installing headers, how many do you want? The head will be straight enough. The manifold will be warped. Have it machined flat. The machinist will hate you. That hunk of cast iron is harder than you MIL's heart. Make sure and clean the head surface real good. I use a small wet stone, dipped in cleaning solvent. Ford did not use a gasket on the manifold. If you insist on a gasket, use a copper gasket from a high performance supplier, like Summit. The tighter you torque those manifold studs, the more tension is on them and the quicker they will break. Start with 15 ft. lbs. I suggest no more than 20 ft. lbs.

Richard
 
Richard - thanks for the info.  As far as I can see, looking at both sides of the engine, I can see that only the aft bolt (passenger side) is broken.  If you have the correct bolt, I will gladly send you a check for the cost of it.  Let me know how much and how to contact you, and I will get it to you.  I would like to get this done before I take it out for two weeks in July so I plan to start on it soon.  My email is below.  Thanks again for the advice.

JR.

[email protected]
 
On my 460 ford v10 the passenger side had all but 2 broken off. It appears that the previous owner tried to tighten them and broke them off, maybe the just broke I don?t know but the heads were not warped. I replaced the studs myself; I got a short angle drill and drilled them out then removed the manifold. I cleaned the manifold and engine head with a wire brush disk on my drill getting it as clean as possible. I then re-tapped the holes and put new studs in that I purchased from the local ford dealer much better quality than original. I went to napa and bought the ?high temperature? manifold gasket sealant, it comes in a tube? a friend of mine runs drag cars and this is all they use to make their exhaust manifold gaskets. I put a large bead around the exhaust manifold and let it get almost cured than put it back on, tighten down one snug then move to the other side, must of taken me 1 hour to get them tight. I repaired this last spring and have put maybe 5000 miles on and it is completely silent with no leaks. This is not an easy job, but much easier than taking the top end of the motor off. If it is not leaking I would leave it alone??Good luck.


PS... if you can not get the stud out and you have enough room on the top end you can have a stainless steel nut welded to the end then simply back it out with a wrench.
 
Interesting concept about replacing these bolts on a regular basis if you're a handy kinda guy.  Would this be a good idea on a diesel too?

Similar to replacing spark plugs every few or four years just to ensure they will come out of the head on a regular basis. 
 
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