Stuck headstuds in aluminum block

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Caprimaniac
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Stuck headstuds in aluminum block

Post by Caprimaniac »

Got this SBF alu Block. 1/2" studs won't come out. Outer studs, maybe water seeped in, or? Middle Three worst.

Tried two nuts counterbound, no Luck. Going to try heat. Any other suggestions?
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Re: Stuck headstuds in aluminum block

Post by mag2555 »

Sounds like there in there with red loctite so the only way to get them out without damage is with darn good amount of heat.
I dought a Aluminum Block has Head bolt holes that pass into the water jacket, but you never know?
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Re: Stuck headstuds in aluminum block

Post by KnightEngines »

Trans fluid mixed with 75% thinners, soak em good & belt the end of the studs good & hard with a bfh.
Leave overnight, belt again then out with the pipe wrench.
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Re: Stuck headstuds in aluminum block

Post by Roy »

I second what knight said, but I would also try a couple heat cycles. I have had success getting corroded in bolts out of 1" aluminum plate using straight ATF and as many heat cycles as it took for it to finally come free. You could also try Kroil by Kano http://www.kanolabs.com/ I've used it on several occasions getting broken exhaust manifold bolts out of cast iron heads. It was the only thing I found which when I got the piece out I could see actually penetrated. Even then they were a pain in the butt to remove so good luck.
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Re: Stuck headstuds in aluminum block

Post by Dave Koehler »

IF there is no loctite involved and you are doing the soak with whatever, tap the end of the stud with a brass hammer.
This can shake/move the stud in the opposite direction breaking the bond and help capillary action move the fluid down the threads.

Edit: Rather than tapping on the end of the stud, use the double nut deal and beat on the nuts.
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Re: Stuck headstuds in aluminum block

Post by plovett »

Heat sounds like a good first step. If they are red Loctite-ed in then acetone may help.

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Re: Stuck headstuds in aluminum block

Post by Dave Koehler »

Concerning heat.
Consider the studs as collateral damage.
It's easy to get carried away heating aluminum so Heat the stud to melt the loctite.

Normally if you look close you can see the loctite.
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Re: Stuck headstuds in aluminum block

Post by 4vpc »

Heat and lots of it every time. I have never once had any luck with any magic potions on studs which are solid. I'm of the opinion they are largely useless for this as the liquid can't get in anyhow.
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Re: Stuck headstuds in aluminum block

Post by Nefario »

If you get scared with heat and beat, there's always alum, warmth, and time...

https://hackaday.com/2015/08/03/dissolv ... e-grocery/

https://www.practicalmachinist.com/vb/g ... um-158766/
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Re: Stuck headstuds in aluminum block

Post by Caprimaniac »

Thanks all for advice. I, try one round of heat and see where that leads. Bit of mixed results on grtting any dissolving fluid into threads, though. Heat, Tap- unbolt...Hopefully

Absolutely no threadlick. Anti- seize only.... Inner holes are blind and studs still covered by rhe stuff. I cannot remember if outers are blind or not- hopefully will discover soon.
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Re: Stuck headstuds in aluminum block

Post by rebelrouser »

Like several said heat would be my first line of attack as well. They are kind of expensive but these induction type heaters really work good. Several of the newer engines have head bolts that go way into the block, if you get one stuck the inductive style heaters seem to always get them loose. I linked to on, several companies make them.

http://www.theinductor.com/induction-he ... lt-removal
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Re: Stuck headstuds in aluminum block

Post by MadBill »

Once you've done what you can with penetrant and heat, I'd weld a nut onto the stud and use an impact gun on it. If the stud's long enough, you might even get away with grinding off the weld afterwards and reusing it.
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Re: Stuck headstuds in aluminum block

Post by Leftcoaster »

Firmly connect a ~300amp arc welder's leads to block and stud respectively, switch on for 10s then check leads, clamps, and stud temperatures

Try tightening then loosening the stud - - repeat 10s applications if the stud doesn't move and heat isn't excessive

The more corrosion around the thread the greater the resistance and the hotter that area becomes

An old time ZA mechanic swore this method was the only cure for Alfa 4cyl engines run without antifreeze

Head studs on those all ali engines pass through a common coolant jacket and into the block
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Re: Stuck headstuds in aluminum block

Post by hoodeng »

If they are locked in good and the fact you have had a crack at them with traditional methods it might be prudent to put the heavy tools away before the mess gets big.You have galvanic corrosion which also leaves a residue that seems to work better than loctite.

look up a local tooling machine shop that has an EDM and get them to burn the studs out, this method will leave the threaded bores in as good a condition as is possible.Large jobs now no longer need to be immersed and can be done with a good stream of coolant. A lot of places will burn a hex into a broken bolt and get onto it with a Allen key if that is all that is required for removal, yours does not look this simple.

Take the block to the machine shop that is going to do the job and run past them what you need,they may have some tips that will facilitate your position. With yours they will probably get you to cut the stud off as close to the surface and burnt the full minor ø out,then pull the coil of thread that remains out, a Helicoil dart works pretty well for this.Obviously you would only proceed in steps as the job develops. Tooling shops are always burning broken stuff out of dies.

I have used this many times on Harley crankcases where screws as small as #10 have been burnt out, also on BSA/Triumph triple crankshaft oil gallery drilling blanking screws.

Cheers.
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Re: Stuck headstuds in aluminum block

Post by Baprace »

Caprimaniac wrote: Tue Nov 26, 2019 6:20 am Got this SBF alu Block. 1/2" studs won't come out. Outer studs, maybe water seeped in, or? Middle Three worst.

Tried two nuts counterbound, no Luck. Going to try heat. Any other suggestions?
Mayby just leaving the studs alone would be the best decision, once you fu%k it up you have alot bigger problem , JMO
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