I got a 1990 e350 with a 460 in it. Its pretty loud and after looking from where the noise was coming from I discovered the last bolt that holds the exhaust manifold to the block was loose because..well..apparently someone tried to tighten it too much and TORE OFF THE CORNER OF THE BLOCK. So basically there is a 1/4 ( maybe less ) gap between the exhaust manifold and the block at this point on the one end ( its seated 'ok' elsewhere). Really there isnt alot of play in it, it doesnt wiggle much. Do you guys think I could just use a bunch of gasket sealer to plug this up? Or should I try to have a shop weld a threaded chunk onto the block so I can seat it properly?

Those are the only ideas I have..thanks

 

Are you sure the chunk isn't missing from the manifold? Would be a lot easier to fix, just replace it.
Actually, the exhaust manifold useually bolts to the head.
If it is the head (or block?), I don,t think welding or sealer will work for long, if at all.
They didn't put any "extra" bolts or studs to hold the manifold on, so you kinda need all the ones it should of come with.

 

Replace the head is probably the only long term repair. Not what you want to hear.

 

Ah I suppose its the head then, whatever the exhaust manifold bolts to is what has a chunk missing. The noise isnt as bad as you would imagine, I can ( and will ) drown it out with the stereo I suppose. Thanks guys

 

Gotta love these engines that you can "lose" a chunk of metal and not erupt a water jacket or oil passage lol...
As has been stated, sealer will just "blow out". Matching a chunk to the head is near impossible. BUT, you MIGHT be able to have a SMALLER, Tapped (and stud ALREADY IN PLACE) piece welded in by someone who REALLY KNOWS what they are doing, but there is one more thing to consider there as well; If that manifold has warped, it may CRACK when you eventually get that end tightened down. "Living with it", I'm afraid is not an option. That dog-house and your heat & air system both are not impervious to air from the engine compartment getting into the vehicle interior. Carbon monoxide is a killer. plus THE HOT GASES are also doing a number on whatever wiring is about.
If you cannot afford to do the head at this time, consider installing a glass-pack muffler to mimimize restriction, but I would seriously get that taken care of, for your health and the health of your passengers.

 

I recently went thru this problem.A customer brought his F800 with a 429 in for an exhaust leak.Found out the gasket between the head and the manifold had split.I removed the manifold to find the last guy who "fixed" it had cut slots in the bolt bosses in an effort to remove broken bolts.Further inspection revealed the mental midget had done the same thing to both heads.The failed gasket quickly escalated into replacing both heads.I had 2 very qualified welders look at the heads.Both told me the heads could be repaired but the cost would likely exceed the value of the heads.Cast iron must be preheated prior to welding then allowed to cool very slowly.If the temperature is not controlled the cast iron will crack.The missing chunk could be replaced by building up the area with welding rod then machining the manifold surface flat and redrilling the bolt hole.The head would have to be removed to do it.Hope this helps.

 

Would I be able to spot weld the manifold to the head? yes I understand its redneck engineering and most likely a bad idea but I figure if its good enough to just help hold that one end tight its all good. The truck ( supposedly ) just had an engine rebuild 11k ago so I highly doubt I would ever have to remove the heads.. but if I did I could quickly grind off the little booger welds. This is just something I came up with.. I dont know if it would work.... tomorrow I will get a picture of the problem on here

Thanks guys

 

if it was mine i would weld it clean it put it in the oven heat it up slow (going to take a while ) you also need the correct electrode for cast iron welding heat to like 225 in the oven ( have welder ready) ttake it out leave oven going once you get it to the welder you can heat the weld area with a torch to get it to around 400F weld it then go put it back in the oven and slowly turn the oven down a little at a time or it will crack once it is cool you can carfully file the weld down to make a good gasket sealing surface

 

Just get another head, it'll not be worth the head ache, you'll spend quite a bit of time trying to make repairs, when the answer is much simpler. To get it ready to heat for welding, it has to be removed and stripped, afterall, you don't want all the steel internals in the oven, not to forget the valve seals. I've welded cast iron before, the backyard approach will result in a deeper break, you damage the structural integrity of the iron by the weld.

 

Wow we spent alot of time discussing this. Was there ever any doubt about it? The head should be replaced. I have some experience with welding cast and agree that the time and energy would be wasted in the end. I would also replace the exhauast manifold just to replace it now, before it cracks as most do at some point. Either way it is alot of work, but once the right way, beats 4 times the wrong way. More money, sure but money wel spent. Think about both heads for that matter. Not what you wanted to hear I know, but do it right, Once.

 

I'd find a set of rebuilt head and use them. That way you know you're not going to have a miss at idle.