I had a noisy Heat exchanger so I pulled it and was about to replace it when I noticed exhaust studs are in pretty ruff condition.

When I tried to tighten it back up the nut started to strip on the bolt coming out of the head.
Any suggestions on what to do or how to clean it up.
i DID PICK UP NEW NUTS BUT CONCERNED THE STUDS ARE GOING TO BREAK.

On a side note: I did find a exhaust leak at the header going into the head.

I also did the lifter free play while I was at it.(Captains way,since I was unable to figure out how to do normal way).
Any insite would be awesome.

This is a 1974 1.8L MOTOR.

Go slowly, use good rust penetrant oil, let them soak for at least a day before tryint to remove them. Work them back and forth to remove them. It you break a stud you have an engine pull and tear down in your future. If you strip a stud and can weld, you can weld the nut to the stud to remove it.
Good luck. Not much room to work around there.
Bruce

I managed to get the header back off.
Just looking for suggestions on ways to clean up the exhaust studs coming out the head.Hopefully this is my best coarse of action.

You can tap the hole to +1 oversize stud. Some have done it with out removing the head BUT if you get off to one side you could have a mess on your hands.

use one of these made for type iv headsClick to view attachment

That's drill bit guide? Can you explain how it works/ attaches in the small confines? I get the concept. Free hand drilling and taping for oversized studs is harrowing to say the least.

Going to go work the old threads with new bolts and anti seize.
With any luck the new nuts will work.
If not plan B re-tap out broken studs.
Thanks for the suggestions and advice.
Grant

Don't know if this is an issue with the aluminum heads but on Fiero's (don't ask) the easiest way to remove studs, broken or not, is to put a nut on the stud then mig weld the nut onto the stud. The heat alone usually loosens even the worst ones so that you can remove without tools. Let someone else weigh in on the aluminum heads before attempting.

I tried to do an under the car threaded insert tap and install and this was the end result.... Well actually the end result was me dropping the motor and swapping the head after the car sat for 3 years.

I feel your pain. I had two studs pull out of the head the last time I put my heat exchangers back on. A step stud is probably your best solution. I was in a time crunch, so I used helicoils from my local FLPAS on the two stripped out holes. I'll be ordering 9MM step studs in case the helicoils fail. Either way, be careful on how deep you drill into the head!

For the intact studs, I picked up this kit:

http://www.sears.com/craftsman-48-pc-sae-m...Q&gclsrc=ds

You run the die over the threads to clean them up. Works very well.

I don't know if it works for 914's but Stephens kit sure makes life a lot easier for 911's

this was the first tool made for 914 ex stud repair on car

the set screws center the tool inside the port stock and oversize guides

this tool is over 30 years old out of my tool box used it quite a bitClick to view attachment

I got the new exhaust all tightened up,seems like it will seal up okay,new copper gaskets etc.

Decided to adjust the valves while I was at it.
Used the Captain guide.

Car run likes shit,calling it a day.
Almost ready to sell the car at this point.

So upset dont even know what to do.
Anyway enuff.

Hang in there, it'll get better. If it was easy....

I went through this, when I first got my car. I tried everything until I just pulled the engine a changed the heads. Putting the header back on with the engine out was much easier. Just a suggestion...

I want one of those fixtures!

Does anyone know where to source the fixture shown in posts #5 and #12?

The right way to do this is to change out all of the exhaust studs. If one or two are bad, the rest at not far behind. Source a stud extractor tool from Sears that is used with a rachet to extract studs that are still intact. Use a drill guide to drill down through the center of any deteriorated studs followed by the use of a properly sized EZ Out to back out the stud. Suggest giving a call to Stromski to see if they have a properly indexed drill guide.

With proper tools, changing out exhaust studs is not difficult. Trying to do it without the right tools can be extremely unsuccessful and frustrating. Don't ask me how I know this!

Use a penetrating oil like PB Blaster or Kroil to aid in stud extraction. Don't waste your time with WD-40. Once all studs are removed chase all the threaded holes with a tap.

The studs (2) aren't the problem. They're out of the heads and not cross threaded or galled up. Threads in holes are somewhat compromised and they just don't 'feel' right as I step up the torque values with the wrench. I have new step up studs already to go and the correct tap.

I just want to know if that or similar style of fixture is available. I don't want to pull the heads. The one time I drilled out for a step up (dif car) freehand I got lucky. Both on angle and knew to not over drill the depth.

The narrative I provided was meant for the removal of exhaust studs threaded into the heads with the heads installed on the engine but with the headers removed. Stromski either has a proper drill guide fixture or can point you to one. Nice guys to deal with. Trying to free hand drilling out studs is a crap shoot that you will eventually lose.

I noted the Stromski fixtures at pelican but they seemed to be for 6's. I try the manufacturer directly. Thanks!

If White1975 doesn't mind, i can make a few of them.

don't mind a bit

[quote name='earossi' date='Sep 16 2016, 08:47 AM' post='2398856']
The right way to do this is to change out all of the exhaust studs. If one or two are bad, the rest at not far behind. Source a stud extractor tool from Sears that is used with a rachet to extract studs that are still intact. Use a drill guide to drill down through the center of any deteriorated studs followed by the use of a properly sized EZ Out to back out the stud. Suggest giving a call to Stromski to see if they have a properly indexed drill guide.

With proper tools, changing out exhaust studs is not difficult. Trying to do it without the right tools can be extremely unsuccessful and frustrating. Don't ask me how I know this!

Would you get a stud extractor in the there...not a lot of room.
Insitu repairs a real gamble IMO,the stud bosses are very weak in this area and are often cracked to start with, the old studs frequently snap off @ the shank were they are mostly rusted away.
One big issue is getting the new stud retapped so that it is square to the hole,really a job with the engine out.
Be very careful chasing the threads with a tap,it tends to make then slightly larger and cause the stud to tear out when you do the exhaust up.
Only mentioning the above because I have seen it many times in the past.

[quote name='porschetub' date='Sep 16 2016, 05:28 PM' post='2399371']
[quote name='earossi' date='Sep 16 2016, 08:47 AM' post='2398856']
The right way to do this is to change out all of the exhaust studs. If one or two are bad, the rest at not far behind. Source a stud extractor tool from Sears that is used with a rachet to extract studs that are still intact. Use a drill guide to drill down through the center of any deteriorated studs followed by the use of a properly sized EZ Out to back out the stud. Suggest giving a call to Stromski to see if they have a properly indexed drill guide.

With proper tools, changing out exhaust studs is not difficult. Trying to do it without the right tools can be extremely unsuccessful and frustrating. Don't ask me how I know this!

Would you get a stud extractor in the there...not a lot of room.
Insitu repairs a real gamble IMO,the stud bosses are very weak in this area and are often cracked to start with, the old studs frequently snap off @ the shank were they are mostly rusted away.
One big issue is getting the new stud retapped so that it is square to the hole,really a job with the engine out.
Be very careful chasing the threads with a tap,it tends to make then slightly larger and cause the stud to tear out when you do the exhaust up.
Only mentioning the above because I have seen it many times in the past.
[/quote]


Everything gets easier with the engine out of the car; but, the OP wants to replace studs with the engine installed. The stud extractor that you can get at Sears is a round and about 1.5" in diameter; so, there should be ample room to use it with the headers removed from the car.

The OP is using "stepped studs" which I assume are standard studs with an increased diameter over the threaded area that screws into the heads. Not sure how plentiful these are or what they cost; but, a more common practice if the threads in the head are damaged is to use a Helicoil or TimeCert. Readily available, inexpensive, and easy to install. Of the two, the better is the TimeCert. Install one and you can then use a standard exhaust stud to complete the repair.

Once the old stud has been removed from the head, you will use a series of progressively larger drills to open the hole. By starting small and gradually increasing drill sizes, the existing hole acts as a guide for the drilling operation until you end up with the drill size required for the proper tap for the stud (whether it be for a Time Cert or a "stepped stud"). The hole will be correctly positioned and plumb with the old stud hole.

Be certain to use a stop collar on each drill to control the depth of the threaded holes.

For me, the tough part of this whole job is the extraction of the old stud, whether it be with a stud extractor or the need to drill out the old stud. Once the old stud is removed, you can chase the old threaded hole and attempt to install a new stud. If the installation of the stud is unsatisfactory (because of damage to the tapped hole), then you can go back and install a Time Cert.

I don't want to hijack the thread, but i have had a leaky exhaust at the head recently.

On investigation it turns out the stud has been helicoiled twice already and now is pulling straight out when i try and tighten it.

There's not metal left for another attempt at helicoiling - is it possible for a professional to weld and redrill / retap the hole?

The engine is a 2056cc and the heads have had work on them so a straight head swap isn't an option.

The aluminum head can be weld repaired; however, the head would have to be removed from the engine to affect such a repair.

In my posting above, I noted that TimeCerts were preferred over a Helicoil. My reasoning was due to the issue you have experienced.

A TimeCert requires a larger hole than a Helicoil; so, I suggest that you look into having the failed Helicoil replaced with a TimeCert. This repair could be done with the engine installed in the car. And, since the TimeCert is stronger than a Helicoil, your issue of a pulled stud may be permanently resolved. If the TimeCert pulls, then a weld repair could always be done.

Also note that the aluminum will tend to move around when it is welded, so there is a good chance the head will need a valve job afterward so that the valve guides and valve seats are concentric. To keep the valves seated correctly when they are closed.

--DD