Fellers - I've got a heat soak issue and have ordered a phenolic spacer to use between the 1 barrel carb & the manifold. Naturally the old studs are too short for a 1/2" spacer and I've got to replace them. I tried a shot of Kroil overnight then a vice grip (that about gave me a hernia getting it on) but they are really in there tight. It's a '58 Studebaker L-head six, BTW. I'm not crazy about using my mapp gas torch, but if I have to, I'll remove the manifold and do it on the bench. Has anyone found a successful way to perform a stud-ectomy without stripping them or breaking them off? Thanks! (Wish I could post a pic but don't have it at a web address)
Use two nuts tightened to each other and turn the lower one. I really suspect you will have to use heat, but I doubt mapp gas will be hot enough. At work, we will heat the surface to red hot and then quench it with water, then turn out the stud.
Patience really helps with penetrating oils. Had to remove the manifold studs same as you, except on the Y-Block. They were reefed in there good. Or bad, I guess. I used Liquid Wrench, sprayed them every day or two, or whenever the spirit moved me, when out in the garage. Tapped on them with a hammer pretty hard, to shock the rust bonds. This helps the product "wick" farther in, or faster. I was skeptical, but after a few days, danged if a couple of them weren't finger tight! They just unscrewed easy-peasey.
He's already used vice grips. Much stronger than two nuts ! NOT enough surface area to use dry ice. The stud's pretty small ! Mapp gas, maybe, maybe not. Not sure that it's hot enough. I'd say the old acetylene torch is your way out. Heat the manifold...only (as much as possible) then your Kroil may help, a lot of people seem to like wax (candle) and drip it into the joint. Put your vice grips back on an rip away. Maybe some tapping with a hammer on the top of the stud(s). And by the way...I'm betting that your current studs, will be throwaway's, too short or not. Mike
The reason old factory studs were hard to remove is most of them were installed at the factory with interference threads...Mopar V8 exhuast studs are the worse....
If all else fails, you could cut them off, & drill them out to just about where the threads show, then use a pick to get the rest of the threads. Finish w/a tap. I'd try this after the weld a large nut on super hot let it cool deal & w/lots of lube, candle wax like Mike mentioned. Last resort is EDM. If you can find a shop w/one, shouldn't be much, if guys aren't asses. Long time to wait, but if you're going to the Stude nats in South Bend, ~ May 4-6th, I can bring some spl stud removers & try it. Doubt there's any torches there, though. ViceGrip makes it a little harder, depending on damage to the threads. Good luck, always good to see another Stude saved/fixed. Marcus...
Second the acetylene torch method. Just heat each stud red hot, let them cool, and they'll probably come right out. Phil
An old time mechanic told me to heat and let cool. Repeat, maybe 5 -6 times. The expansion breaks down the rust, and eventually it lets go. Using a good penetrating oil helps. It works, especially on horizontal bolts where getting the oil in is difficult. Never ceases to amaze me how those old guys, like my Dad, got so much smarter as I got older.
Mike VV is on the right track here. If you heat the stud it will expand and bind things up even tighter. As much as possible, try to mainly heat just the manifold around the stud. What you're hoping to do is make just the manifold expand away from the stud and break the grip between the threads. Probably a job for an acetylene torch, as already mentioned.
Mapp gas usually works for me. Concentrate the heat on the manifold mainly. I go with a few heat cycles too, use a penetrating oil in between cycles. I like MMO the best, my dad turned me onto it for old rusty bike chains. I have a small plastic bottle of it with an invitro plastic wand on it.
I just removed the studs that connect the head pipes from both exhaust manifolds while on the engine. Heated the manifold area around the studs to red with oxy/acetylene and then backed the studs right out. Worked great.
Tom, I have something similar to this https://www.weldingforless.com/prod...anty-fuel-gas-kit?_pos=6&_sid=5ec5d29fd&_ss=r About $110. You do have to find a little bottle and get it filled too. Not as convenient as MAPP, they are hot and fast. I have torches, but this is my go to for studs. I got a cheap stud extractor from Amazon It works well. Way bigger around than the nice roller extractors though. I'm also a proponent of wax in the hot joint. If this fails, I weld a nut on. MAPP vs Air-Acetylene (Google) Air-acetylene produces a flame temperature of around 4000° F (2200° C). This is hot enough to solder aluminum, work glass, repair radiators and braze plumbing fixtures. It is not hot enough to weld steel. When acetylene is burned in pure oxygen, the flame temperature may be as high as 5730° F (3166° C). Although acetylene has a higher flame temperature (3160 °C, 5720 °F), MAPP has the advantage that it requires neither dilution nor special container fillers during transport, allowing a greater volume of fuel gas to be transported at the same given weight, and it is much safer in use. With studs, luck doesn't hurt either Mike
Heat is usually what ends up working but as others said, put the vice grips or double nuts on, put the Kroil on again and tap on the top of the stud while trying to turn it. How hard you tap or turn is an acquired skill, usually learned the hard way..
I don’t have much to add here that hasn’t been said, but I wonder if using the double nut method, maybe an impact hammer could be used to prevent twisting the stud off. Patience is not my strong point and I often reef too hard without waiting for the penetrating oil to do it’s magic.
With all due respect, heating the manifold with a torch risks cracking it and other damage. The heat in this case is not to promote differential expansion, but simply to break the rust bond. Heat the studs to red, let them cool, take them out.
50/50 mix of atf and ketone. After learning that here, I put that shit on everything amazing how good it works.
I have had good results heating nuts, bolts and or studs. I find that a 0 or 00 tip or a bit larger on a brazing torch allows precise concentration of the heat applied. This limits the heat more to the desired component and helps prevent ancillary heating where not desired. The ox- acetylene flame can really be adjusted to very intense and controlled heat. Just a suggestion, works for me.
OK here’s the physics of heat on steel !!! When you heat steel ,, in this case the studs they expand . Let them cool completely , do this 3 times ,when steel cools it shrinks 3 times more than it expanded ,so the studs will be slightly smaller .. grip ‘‘em tight , move back and forth a little more each time, we’ll you the idea .
All, well most, good ideas! I also use a impact hammer and a blunt bit, to vibrate the stud. Do this very easy, usually in a downward motion. Use the many hits of the pneumatic hammer to set vibrations in the stud. This with heat and your special oil and patience should get the stud out. Bones
I have used the ATF and Acetone to break loose a seized up 4cyl flathead in another jeep I had works great.
Intake manifold studs generally don't get rusted in like exhaust manifold studs. Maybe the Vise Grips weren't biting in enough. I'd use Truckdoctor Andy's double nut technique, it's always worked for me on cast iron intakes.
Heat the stud cherry red and then g have a coffee,I f cool when you get back then give it a try. Repeat if necessary.
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