Bad News!

After finally getting my backordered Thorley headers in the mail I was just finishing putting everything together. I was filling the coolant and I heard water dripping underneath. I went to the back of the block and a stream of water was coming out a small hole where the machine shop apparently drilled the exhaust manifold hole through the water jacket and block when I had them remove the broken stud! Do you think that this is going to be salvageable. The hole is about the size of the tip of a pen. Unfortunately I had the work done 2 months ago and did not notice anything then.

 

That BLOWS! I'd definitely go back to the shop and see what they will do for you.

Now, what can you do in the mean time since the engine is already in and you're trying to get it back on the road? Here's one idea: degrease and dry the hole and bolt and use high-temp silicone RTV to seal the bottom of the hole as well as the threads when you install the bolt. But, with headers, you almost always need to snug up the bolts after they have been run for awhile, and doing this may break the seal on the cured RTV. Maybe install a stud such that it won't be rotated once installed?

Another possibility would be to seal the BOTTOM of the hole (and not the threads) with something like JB Weld. Again cleaning and drying hole thoroughly would be critical first. Then dab JB Weld into bottom of the hole and install a (temporary glue-holding) bolt with a bit of light lubrication on the threads and on the end of the bolt (so the epoxy won't glue to the bolt). You will have to determine the proper depth for this temporarily bolt such that the epoxy is thick enough to properly seal, but not so thick as to cause interference with your permanent bolt. Any excess epoxy would be forced though the hole into the water jacket which will help anchor it in place. Then remove the bolt after the epoxy sets up but not fully hardened.

I'm not terribly in love with either of the above ideas due to my long-term concerns about the heat cycling in this area and its effect on the sealant (the high-temp RTV would probably be the better sealant of the two to withstand this), but either of them could work, at least for awhile.

Sorry to hear about your situation, I feel your pain!

 

I'm doing this same thing. Where did you get your stainless hardware?


Thanks, Pete

 

I just bought regular 316 stainless bolts and washers at the local hardware store.
3/8-16x1 3/4" IIRC.

There are three studs on my exhaust.
One to hold the dipstick and two for the warm air shield on the passenger side.
I have some er316 for my Mig welder so I just bought a foot of stainless threaded rod and zapped some nuts on.

Use Loctite PST.
This is an anaerobic pipe sealant.
That is what I've always used on bolts or studs going into water passages.
The cylinder head is not going to get hot enough for it to fail in there.

 

I would run one of them into the hole,thay do have different lengths,find the shortest 1 possible & bottom it out with JB weld just dabed on the end as mentioned. Then clean up the threads with a bottom tap.You should have enuff threads left for the header bolt.

 

Jim has the right idea using PST it works in this case very well.

 

X's 3 on the PST

 

Wanted to thank everyone here that has talked about stud replacement. I spent four days (total of 14 hours) replacing three studs on the drivers side, on the way to replacing my rusted off dip stick tube.

Only mistake I made was going about it half a**. Word of advise, If your going to do the job dig in. Remove all the parts to get in there and make the job successful. I tried working around things for the longest time and just made the job worst. Once I removed the wheel/tire, inner fender, Shock and shock support bracket, all wiring, steering wheel shaft, egr tube, air inlet system, Y pipe and anything else in my way - it wasn't that bad. Also forget the electric drill program and any thoughts of using a easy out (could be because my truck has 285k on it and those studs where committed) and above all remember PB penetrate was the savior in this endeavor. The trick was a right angle air drill and a stubby drill (cobalt). Start with something around .070 in size. Drill to depth and then proceed with tape size drill and tap.

My I also suggest if your there and the dip stick tube looks rough, go for it. Mine was broken off flush. Ended up feeding a wire through it and dropping into the pan and fish it out. Big tip, use a die grinder to remove the top locating ring off the old tube and then hammer through with the use of a ground down ⅜ extension (2 where needed - buy cheap and pitch after) and my cell phone (iPhone 6 - used the video feature) to see what I was doing as the oil feed housing is in the way.

Again if it wasn't for the 20 some pages I read on here I would still be under my truck instead of writing to you all.

Jeff from Byron - F-350 SD V-10 4x4 Crew Cab Long bed Dually with 285,000 miles on original motor.

 

Well I have a '76 460 in a class C that has a broken exhaust manifold bolt that I am going to have to fix this year. Here where the snowball effect comes into play. I'm not even going to try to fix it with the engine in the van front end. Actually I'll spent a couple hours trying. So then motor will be coming out and I'll replace all exhaust manifold bolts and gaskets. Now since I'll have the engine out if I have to end up pulling the heads I may as well do a valve job. If I am going that far I think I'll have the exhaust seats replaced with the hardened seats. If the heads are on the bench I may as well do a little port & polish and exhaust gasket matching. Oh boy here is where I would or will go sideways on myself. I may as well pull the oil pan replace the oil pump with a Melling's. Now I am down to a short block maybe replace rear seal and the timing chain to a pre '71 chain. This motor only has like 73k on it and not having the funds to do a complete over hopefully I can stop myself at that.

It is funny how I am taking something as simple as replacing exhaust manifold bolts and letting it snowball into alot more than needs to be done. But maybe I'll be the 1% who can get all the rest of the bolts out with the engine in and be done. I doubt it everytime I touch something something goes wrong.

So thanks to all for sharing their insight on the subject. I am not looking forward to this project.

 

That's the road I went down also. People kept telling me "well as long as you have it this far, you might as well(insert new part or rebuild here)" I had the far back bolt on the #7 cylinder broken off, but the rest came out just fine. I drilled out the broken one and threw a helicoil in. I used copper anti seize when I installed my new ones, and have had them in and out a few times since then with no issues.

Sent from my iPad using IB AutoGroup

 

When ever I have to drill out a bolt or stud I always use a left handed bit. Many times the bit will spin the busted off bolt/stud right out.

 

I am not sure what others have experienced, but i never use gaskets on iron manifold and heads. Metal to metal with just a smear of Permatex Ultra Copper is a far better solution. Those foil gaskets always fail. I have never had a leak with this repair.

I did my 460 manifolds a few months ago after I first bought it. The PO had had foil gaskets put on at some point. They were blown out and leaking. I removed the manifolds, sanded them with my DA to get them flat and then I tapped every hole in the head and ran a die over every bolt (replaced a few bolts). I smeared a little PUC on the manifolds and re-installed everything. No issues at all.

I was a dealership tech for GM, iron manifolds never had gaskets unless it was an alloy head vehicle. Not sure what Ford did at the dealer.