Drilled hole in block

K

ksousa

Junior Member
I had that sickening feeling of seeing water run out of the hole that I was drilling in the side of my block.
One of the studs that holds the exhaust and intake manifolds on had broken off of our '29 RPU. It was flush with the side of the block.
I stripped the side of the motor. Made one attempt at welding a nut on the end of the broken stud with no luck. Because of the size of the bolt and the heat that I'd need, I decided to try and drill out the stud.
I was careful enough with the drill but when I put an "easy out" in the hole and starting trying to work it backwards, the easy out pushed through and into the water jacket and she poured water out of the stud hole.
Not being an expert on the construction of these blocks, is there a repair for this?
 
some studs go into water jackets . check with a rebuilder before you panic ...... steve
 
Prepare the hole for the installation of a "Heli-coil" the when installing the heli coil apply the "red" lock tite on the helicoil and thead it in let it set well the install the proper sized stud and the repair will be a good as new and no leak.
Gord. B by the Bay
 
It's best to weld a flat washer to the broken stud FIRST, then weld a nut to the flat washer. This makes the welding easier and the 2 seperate heat cycles helps to free the broken stud.

Anyway, it's not the end of the world, nor your block! Just finish rethreading like you were going to do and be sure to put sealer on the block threads of the new manifold stud. As long as the stud holds and no coolant seeps out, you're good to go. If you're careful you can uncover the origianl threads in the block.

Start by center punching the exact center of the broken stud, then use a 1/8" bit and carefully drill to the end of the stud, then keep redrilling the hole using larger and larger bits until you can just start to see the threads. Now take a dental pick and try pulling the threads out. Hopefully you can get at least a few rows down, then when you try to run the tap in it will probably grab the remaining threads and turn them. Now try removing the tap and hopefully the remaining threads will come with it. If not, at least they are loose so you can work them out.

If you can't uncover the original threads, then cutting new threads may make them so weak that a heli-coil may be needed. It's been many years since I've had to use a heli-coil.
 
Depending on how your stress is at this moment:D, --or what tools you have access to, it may also be worthwhile for you to consider contacting a local machine shop that has a wire EDM to remove it safely. You could either find someone locally that has a car trailer you can borrow, --or have a rollback wrecker move it for you to the machine shop. Most machine shops would only charge a minimum charge for this (likely $20-$30) and they can usually do it without any damage to the threads on the block. Most machine shops will also have many specialty Loc-tite products on-hand so he could use his tap to clean the threads and if you hand him the new stud, he can likely install it where it would not leak saving you the cost of purchasing a whole tube of Loc-tite.

Just a thought.............

.
 
alternative to Helicoil......

when we first got Our Town Sedan, the engine was blowing bubbles in the radiator.

when I re-torqued the head, it pulled out a Helicoil from stud #13.

I got a threaded insert, drilled out the hole oversize, tapped it and sealed the insert in with black Permatex form-a-gasket. then I could use a standard sized stud.

this solution seemed MUCH more substantial than the Helicoil and 5,000 miles later it is still hanging in there.

if you take it to a machine shop to get the broken stud out, they can do this fix for you.
 
You can use Nickel welding rod if your careful or you can braise it closed. Both methods have to be done correctly. I have used both methods on a couple of tractors that I have to seal hydraulic leaks in the cast iron and they have held for over ten years each. For a temporary fix you could get some high temperature silicone and fill in the hole along with applying gasoline teflon tape to the threads. Who know may by applying the silicone and tape it might prevent any water from leaking and be fine for a good long time.
 
Studs are in water jackets quite often, if you have salvaged the threads or have put a helicoil in, use a teflon sealer, its in a small tube a little bigger than a crazy glue tube, I believe it says high heat teflon, I use this on all head studs that are in water jackets and no problems.
 
As already referenced by a few above it may be of interest to you to know that many more modern engines are made with stud holes that are open to the water jacket and it is not a problem. For example, all the Dodge/Plymouth V8 models of the muscle car era have exhaust manifold stud holes exposed to the water. The use of a sealing compound on the threads was the standard if one of the studs backed out when removing the manifold.

The Model A water pump has an exposed stud hole (on some heads) exposed to the water. In addition, the bottom of the boss of the stud holes in the Model A block often break off nowadays on many a Model A and expose the holes to the water.

Nothing to panic about.

Moreover, a threaded insert is nice but there's also nothing wrong with the use of a Heli-coil. A Heli-coil is stronger than the cast iron and the ones that fail are usually due to improper installation.

Last but not least it's a good repair in many cases but I'd steer clear of a nickel weld or braze.



.
 
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OK so I calmed down and listened to you guys and methodically fixed the threads, sealed it, and put the side of the motor back together.
I filled her up with anti freeze and saw no leaks.
Fingers crossed, I started her up and no leaks.
HOWEVER, I'm now pushing LOADS of white smoke through the exhaust. She didn't smoke imediately, but after 1 to 2 minutes I had smoke starting to come out and it got heavier as she warmed up.
So now I'm nervous that somehow drilling through the exhaust manifold stud into the water jacket has somehow caused a water leak into the piston or combustion chamber?
Is that possible or is it possible that I have a temporary overflow of water situation or something that might just go away or ??????
thanks for any input.
 
ksousa said:
OK so I calmed down and listened to you guys and methodically fixed the threads, sealed it, and put the side of the motor back together.
I filled her up with anti freeze and saw no leaks.
Fingers crossed, I started her up and no leaks.
HOWEVER, I'm now pushing LOADS of white smoke through the exhaust. She didn't smoke imediately, but after 1 to 2 minutes I had smoke starting to come out and it got heavier as she warmed up.
So now I'm nervous that somehow drilling through the exhaust manifold stud into the water jacket has somehow caused a water leak into the piston or combustion chamber?
Is that possible or is it possible that I have a temporary overflow of water situation or something that might just go away or ??????
thanks for any input.
Click to expand...

Unless you ran that drill bit in about 3" :eek:, you certainly didn't hit the piston or bore. What concerns me is the easy-out you used, They expand into the drilled hole, and worse-case, you may have opened a crack into an exhaust port. Remove the intake/exhaust manifolds, top off the rad, and apply 2-3 psi. Look for any water into the exhaust ports. Even if you do have a crack, it is fixable. I'm thinking more than likely you have a head gasket leak. Try air pressure to each bore and look for an uplift in the water level.
 
Thanks Mike,
I'll do some more testing. I know that I did not drill or tap anywhere close to three inches deep, so I feel better.
The truck belongs to my son and he had driven it around town a number of times without the smoking.
One thing that I did notice that was different was that when I drained the water out of my newly "created" hole, I only drained about a gallon or so.
However after sealing and replacing the stud, I put in just shy of three gallons of antifreeze and water.
Think it's possible that a previous low water level was hiding a head gasket problem or some other problem?

thanks
Kenny
 
Paul,
I had just changed the oil two weeks ago. I ran the motor for maybe a half hour before I caused the water hole leakage.
I've run the motor for a total of 5 minutes since repairing the water leak and having this smoking issue.
I just checked the oil wondering if it would be milky and overfull but it's exactly where it should be and perfectly normal looking in color and appearance.
 
ksousa said:
Paul,
I had just changed the oil two weeks ago. I ran the motor for maybe a half hour before I caused the water hole leakage.
I've run the motor for a total of 5 minutes since repairing the water leak and having this smoking issue.
I just checked the oil wondering if it would be milky and overfull but it's exactly where it should be and perfectly normal looking in color and appearance.
Click to expand...

I don't think maybe 5 Min. is long enough to clean the cylinders out, some time it takes 1/2 hour to get rid of Mystery oil smoke. Blue smoke oil, Black smoke gas, White smoke antifreeze. Water vapor will very. Herm.
 
Weak Helicoil experience: Someone hand-drilled out a head stud off-center on a car that I bought. I redrilled for a Helicoil at the correct location, but the previous off-center drill did not give the Helicoil a full 360 degree support. It pulled out at about 55 foot-pounds of torque on the head nut. (I was using a high compression head). Re-installation with J-B Weld did not help. I then tightened it to only 45 foot-pounds and it has held for 5 years.
 
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