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So I'm pulling off my 5k head to do some stuff, however, I got all but 1 off. (because I'm smart and rounded it) After about an hour of working. My dad welded a ring spanner onto it and finally got it off, but it snapped inside. After getting everything else off. the Head is free from all the block but that one corner, could the bolt possibly broken threaded between the two? Cheers.

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Hi James,

                 Let me get this straight.  You are removing the 5K head, & got all head bolts out, except one,  in the corner of the head, which wouldn't budge.

So you dad welds on a spanner, because the bolt head had rounded corners.  The bolt came out, but in the process broke off.  So the bolt head is off, but the head still won't come free of the block.  If the head bolt had broken off in the block, or at the surface of the top of the block, then the head would come away easily.  If it is still stuck, then the bolt must have broken inside the head, & must be twisted or distorted, such that the head won't come free.

If the bolt head with welded spanner has come away, then you should be able to look down the hole in the head & see the remaining mangled/twisted bolt shaft.  Be very careful levering away the head, as the head is aluminium.

You will also need the remaining part of the bolt shaft, to be able to unscrew t from the block, once you've put some penetrating oil down the thread.  Might take a day or so to free it.

Cheers Banjo 

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9 hours ago, Banjo said:

Hi James,

                 Let me get this straight.  You are removing the 5K head, & got all head bolts out, except one,  in the corner of the head, which wouldn't budge.

So you dad welds on a spanner, because the bolt head had rounded corners.  The bolt came out, but in the process broke off.  So the bolt head is off, but the head still won't come free of the block.  If the head bolt had broken off in the block, or at the surface of the top of the block, then the head would come away easily.  If it is still stuck, then the bolt must have broken inside the head, & must be twisted or distorted, such that the head won't come free.

If the bolt head with welded spanner has come away, then you should be able to look down the hole in the head & see the remaining mangled/twisted bolt shaft.  Be very careful levering away the head, as the head is aluminium.

You will also need the remaining part of the bolt shaft, to be able to unscrew t from the block, once you've put some penetrating oil down the thread.  Might take a day or so to free it.

Cheers Banjo 

Hey Banjo, yeah that's exactly what happened, it snapped off leaving 3/4 of the bolt in there. if I put lubricant down then use an Easy out or tool of the like would that also release it?

 

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Hi James,

                  The head bolts on the K series engine are a substantial bolt.  There are probably harder aftermarket ones available, but I have never heard of a standard head bolt snapping off like that.   From what you describe it sounds like it snapped off just below the hex head of the bolt.  It sounds like the bolt is so rusted in at the thread, that the bolt thread has not moved at all.

You really have no option, other than to lever the head & block apart. In doing so, you may score the inside of the head bolt hole in the head, but it is soft, so should not do too much damage.

What are the condition of the other head bolts you removed OK ?   Was this bolt on the back or front corner of the head ?  My guess is it was a rear corner, as the back of the engine runs hotter than the front as the engines get older, & the cooling water circulation at the rear of the block deteriorates, as gunk builds up in the water jacket.

Were there big thick hardened washers under the head of each head bolt ?   If the washer is omitted, then the bolt can bottom in the threaded hole in the block, causing all sorts of grief.

From memory, not all K series head bolts are exactly the same length.  There is always a possibility that the bolts are too long.  This problem can be exacerbated, if the head has been excessively skimmed at some time.

I would suggest that once you get the head levered off, that you take the block to a machine shop where they can professionally remove it, although it might take a few days.

I'd hate to see you lose a good 5K block, if you have a go, & it doesn't work out.

A machine shop has several options.  If they can't get it to move after a day or so of penetrating oil, they can cut the head bolt off flush with the block top, they then can clamp the block & drill/machine out the centre of the bolt, right to the bottom. More penetrating oil, & a large easy out, might then prove to be your salvation.

Let's know how it goes.

Cheers Banjo

 

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1 hour ago, Banjo said:

Hi James,

                  The head bolts on the K series engine are a substantial bolt.  There are probably harder aftermarket ones available, but I have never heard of a standard head bolt snapping off like that.   From what you describe it sounds like it snapped off just below the hex head of the bolt.  It sounds like the bolt is so rusted in at the thread, that the bolt thread has not moved at all.

You really have no option, other than to lever the head & block apart. In doing so, you may score the inside of the head bolt hole in the head, but it is soft, so should not do too much damage.

What are the condition of the other head bolts you removed OK ?   Was this bolt on the back or front corner of the head ?  My guess is it was a rear corner, as the back of the engine runs hotter than the front as the engines get older, & the cooling water circulation at the rear of the block deteriorates, as gunk builds up in the water jacket.

Were there big thick hardened washers under the head of each head bolt ?   If the washer is omitted, then the bolt can bottom in the threaded hole in the block, causing all sorts of grief.

From memory, not all K series head bolts are exactly the same length.  There is always a possibility that the bolts are too long.  This problem can be exacerbated, if the head has been excessively skimmed at some time.

I would suggest that once you get the head levered off, that you take the block to a machine shop where they can professionally remove it, although it might take a few days.

I'd hate to see you lose a good 5K block, if you have a go, & it doesn't work out.

A machine shop has several options.  If they can't get it to move after a day or so of penetrating oil, they can cut the head bolt off flush with the block top, they then can clamp the block & drill/machine out the centre of the bolt, right to the bottom. More penetrating oil, & a large easy out, might then prove to be your salvation.

Let's know how it goes.

Cheers Banjo

 

Thanks for the info Banjo, it is actually one of the front ones that was stuck, all the others were quite easy and had a nice "craack" as I undid them, however, we this this one was destined to snap as it didn't have any give. all the bolts have good looking washers, and I agree the head bolts are different lengths. and as soon as I get it off it'll go to the machining place, I don't wanna dance with death. I'm swapping the head with someone for a worked one so I want to keep it alright. 

Cheers again :)

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Hi James,

                 I wish you luck at the machine shop.  I think head bolts are a very overlooked item, but can cause issues, if not installed correctly.  When our K Series engines are 40 odd years old, you never quite know what has been done to them by others, in the past.  Theoretically, the head bolts stretch when they are pulled down, & should be replaced at some stage, but it doesn't happen very often.

The first thing to check when putting a head back on a block, is to ensure the threaded holes in the block, for the head bolts are perfectly clean. Some spray degreaser & a air nozzle, can usually fix this, but you must wear goggles. Use a bit of stiff wire to unblock any rubbish at the bottom of the holes. It is a good idea to run a die down the thread in the hole, but if not available, then a head bolt, with a perfectly clean thread, and a bit of light oil on the thread, will usually suffice.  You should be able to wind the head bolts down by hand, without any binding. 

Next ensure all the head bolts are the exact same length. Take one head bolt, & fit the thick hardened washer, & screw it into a hole until it touches the bottom.  Pull the washer to the top, & with a steel ruler, measure the distance between the top face of the head, & the underside edge of the washer.  Note this measurement "A" to the nearest mm.

Now measure the thickest of the head from the bottom face of the head, to the top of the head bolt boss.  Add to this the thickness of the head gasket, which compressed, will normally be about 2-3mm.  This total measurement should be approx. 10mm greater than measurement "A", previously measured.  If not, then you might have the wrong length head bolts.

This is very important, when swapping heads.  You do not want the head bolts ever bottoming out in the bottom of the block threaded holes.

I personally have always put some sewing machine oil on the head bolt threads, before fitting & tightening them up, in sequence as per the manual. A drop of oil on the top of the thick washers does not go astray either.  Never tighten head bolts down on aluminium heads without using the thick hardened washers !

Oh, and use a tension wrench.   If you haven't got one, then borrow one.

Cheers Banjo

 

Edited by Banjo

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49 minutes ago, Banjo said:

Hi James,

                 I wish you luck at the machine shop.  I think head bolts are a very overlooked item, but can cause issues, if not installed correctly.  When our K Series engines are 40 odd years old, you never quite know what has been done to them by others, in the past.  Theoretically, the head bolts stretch when they are pulled down, & should be replaced at some stage, but it doesn't happen very often.

The first thing to check when putting a head back on a block, is to ensure the threaded holes in the block, for the head bolts are perfectly clean. Some spray degreaser & a air nozzle, can usually fix this, but you must wear goggles. Use a bit of stiff wire to unblock any rubbish at the bottom of the holes. It is a good idea to run a die down the thread in the hole, but if not available, then a head bolt, with a perfectly clean thread, and a bit of light oil on the thread, will usually suffice.  You should be able to wind the head bolts down by hand, without any binding. 

Next ensure all the head bolts are the exact same length. Take one head bolt, & fit the thick hardened washer, & screw it into a hole until it touches the bottom.  Pull the washer to the top, & with a steel ruler, measure the distance between the top face of the head, & the underside edge of the washer.  Note this measurement "A" to the nearest mm.

Now measure the thickest of the head from the bottom face of the head, to the top of the head bolt boss.  Add to this the thickness of the head gasket, which compressed, will normally be about 2-3mm.  This total measurement should be approx. 10mm greater than measurement "A", previously measured.  If not, then you might have the wrong length head bolts.

This is very important, when swapping heads.  You do not want the head bolts ever bottoming out in the bottom of the block threaded holes.

I personally have always put some sewing machine oil on the head bolt threads, before fitting & tightening them up, in sequence as per the manual. A drop of oil on the top of the thick washers does not go astray either.  Never tighten head bolts down on aluminium heads without using the thick hardened washers !

Oh, and use a tension wrench.   If you haven't got one, then borrow one.

Cheers Banjo

 

Cheers Banjo, I can't thank you enough. I'll use that guide when putting it back on!! I kept letting it sit in Wd-40 then flushing it and doing it again. After about 6 hours, my dad and I gently tapped one end of the head as we chocked the other end (making sure not to scare it) amazing how that little bit of metal can make me go insane :^)

15150456675922108419879.jpg

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Hi James,

                  As it has broken off so far up, under the hex head of the bolt, you could possibly get a piece of steel bar,  a metre long, & drill a hole in it, in the middle, so it just clears the bolt.   As you have a welder, you could weld the bar to the broken bolt, & then use it like a "T" bar, to put some force into it.   Weld it, as low as possible. (take the water pump off)

If it doesn't move at all, or the bolt shaft starts to twist, then it will have to be off to the machinist, as you don't want it breaking off again. Being up front, it might have got some water into it, and is rusted in proper.   You don't want it breaking off just below the surface of the block, so the machinist doesn't have a flat surface to get an exact centre point for drilling it out.

Good luck, & let us know how you go.

Cheers Banjo

 

Edited by Banjo

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31 minutes ago, Banjo said:

Hi James,

                  As it has broken off so far up, under the hex head of the bolt, you could possibly get a piece of steel bar,  a metre long, & drill a hole in it, in the middle, so it just clears the bolt.   As you have a welder, you could weld the bar to the broken bolt, & then use it like a "T" bar, to put some force into it.   Weld it, as low as possible. (take the water pump off)

If it doesn't move at all, or the bolt shaft starts to twist, then it will have to be off to the machinist, as you don't want it breaking off again. Being up front, it might have got some water into it, and is rusted in proper.   You don't want it breaking off just below the surface of the block, so the machinist doesn't have a flat surface to get an exact centre point for drilling it out.

Good luck, & let us know how you go.

Cheers Banjo

 

Hey again banjo! Thanks for the reply once again I thought of welding a few nuts onto it and using a socket, but as you said. I don't want to risk it snapping into the block, as it seems pretty damn stuck. Cheers man!

 

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shitballs. id be heating up that corner of the block and dry icing the bolt thread because that always works for me on other parts of the car. in ur case ud have to lock two nuts on first and probably weld them to the thread before doing that.

i think if u fail using brute force on that much exposed bolt, an easy out will have no chance.

Edited by rebuilder86

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Hi James,

                  Interested to know whether you were able to get that "pesky" broken front head bolt out, & how you did it.

Cheers Banjo

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12 minutes ago, Banjo said:

Hi James,

                  Interested to know whether you were able to get that "pesky" broken front head bolt out, & how you did it.

Cheers Banjo

Hey there Banjo, unfortunately I haven't had time to get the bolt out as of yet, but. I think i'm going to heat the bottom of the block a little then weld a nut or 2 on the top and hopefully be able to crack it that way 

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On 1/20/2018 at 9:01 AM, Banjo said:

Hi James,

                  Interested to know whether you were able to get that "pesky" broken front head bolt out, & how you did it.

Cheers Banjo

Hey Banjo, and everyone.

 

I finally got it out. It was my turn at welding so don't mind the horrendous welds, but I was strong enough to crack it.

IMAG0235.jpg

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Good One !  Did the threads indicate whether any of the penetration oil got through, or was it complete rusted on ?

Cheers Banjo

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