Rounded out Head Bolt extraction help

[jimmythesaint]

Ive searched and searched but this seems to be the first question about a head bolt.

Im trying to pull the head of my car and got all but one of the head bolts cracked loose. The last one I get to is already rounded out, and I have no hope of removing it with the 10mm star/allen socket.

Its the bolt to the far left exhaust side.

I went to sears this morning and bought a set of rounded bolt removers, and they seem like they will grip the round outside edge of the head bolt. Only problem is its too big to fit in the tight space. The extracters are pretty big and Ive even removed the camshaft to free up some space but the side of the head and the valve spring are in the way. Maybe if I removed the valve spring I could squeeze the extractor in there but I dont think it would have enough room to get back out and I have no way of removing the valve spring.

Does anyone have any other ideas on how to remove this rounded out head bolt? I think if I could weld a bolt ontop of the head bolt I could get it but there is the space issue. The bolts arent threaded into the head so it COULD be drilled but that is risky and this is a good head and I really dont want to mess it up.

Just wondering if anyone else has dealt with a rounded out head bolt and how they got it removed.

 

[gstryyder]

If you cannot find a rounded bolt extractor socket to fit it... You could try doin your welding thing... But if i was in your situation i would drill the head of the bolt off. (if you could do it with a reversed drill bit (like i would) it moght grab and back it out. otherwise... off with its head. They are not threaded into the head so once you drill the top off it should move on up...lift off the head, then continue on with the removal of the bolt shaft.

 

[jimmythesaint]

Yeah drilling the top off may be a good option. Its just tricky ### I certainly dont want to damage the head and Im reserving it for a last resort. Can anyone offer any advice on how to do this? Ive never had to before. I wouldnt think getting the bolt shaft out of the block would be a problem a pair of vice grips couldnt handle.

I dont think a reverse drill bit or "easy out" will work for this. The head bolts are torqued down quite a bit and they are pretty tough bolts. The reverse bit would likely break off before the bolt came loose and then Id have a new problem.

 

[gstryyder]

this is just how i look at it. my reverse bits do the same as the forward bits. except its the same direction as the bolt comes out... not like it would come out. its a "if ya get lucky"... but worth using the different bit...as far as getting the bolt out when the head is off... if a good set of vise grips and some elbow grease doesnt work you can protect the block, and weld something on at that point. a nut that would slide over very tight welded top n bottom should be able to hold enough for you to then impact the rest of it out..

by the way it is not too hard drilling the head of a bolt off. you just need to be careful and take your time using several bits going up in size... ever drilled a rivet? i've done this with several bolts on different vehicles... works well if you do it right.

hope ya get that sucker man. =P let us know how it goes.

 

[snakeyes711]

I would drill the head off the bolt too, and your not goind to be damaging anything except the bolt.

G/L

 

[Rob10_99]

You could weld a nut on the top of the whole bolt, something 6point, fill the inside with weld.
Weld your stripped out allen socket drive into it, most of the time this happens is because the socket has a rounded end on it, try to take your old one to a grinder and make it flat at the tip, that should help quite a bit in the future.
Other than welding the allen or nut, there's not much else you can do, drill the head of the bolt off, thats about it.

 

[jimmythesaint]

You could weld a nut on the top of the whole bolt, something 6point, fill the inside with weld.
Weld your stripped out allen socket drive into it, most of the time this happens is because the socket has a rounded end on it, try to take your old one to a grinder and make it flat at the tip, that should help quite a bit in the future.
Other than welding the allen or nut, there's not much else you can do, drill the head of the bolt off, thats about it.

Its not the tool thats rounded, its the bolt and it was like that before I even touched it. Whomever did the head job on the car before I bought it really did a number on that one bolt.

Thats not a bad idea though, I have a cheap harbor freight allen socket somewhere I could try welding to the bolt and that just might do the trick.

 

[snakeyes711]

How about beat a one size bigger hex into it. Whats the MM size? Get one size bigger file a bit off the edges , and pound it in there. I had to do that with one of my bikes foot peg bolts. Just a suggestion, it seems you want to drill it off at the last resort, so try that first.

 

[jimmythesaint]

Well this can be marked resolved now as I got the bolt out.

I had forgotten that there are washers between the bolt head and cylinder head so drilling it wasnt as scarry as I thought.

However, those bolts are harder than any drill bit I could find. Basicly they laughed at my drill bits. I was able to get shavings off the bolts but thats about it.

I did manage to finally get the bolt out though. I used a 1/2 inch titanium nitride coated drill bit and drilled into the bolt head at an angle. After several minutes of drilling from different angles I made enough of a groove in the bolt that a socket was able to grab the bolt and break it free.

Thanks for everyones help.

 

[95blackGsTurbo]

For future reference these are your ticket to easy removal. Sears has them.
IRWIN Hanson Hex Head Multi-Spline Screw Extractors - 522/532 Series