4age head bolts rounded and over tightened, possible siezed, what do I do?

[wiso]

I am taking a head off a 4age bigport engine and ran into a real spot of trouble. 4 of the middle bolts seem to be either seized or over tightened. I notcied the socket when I put it on was a little loose so I had a look at them and the heads are rounded in a clockwise direction.

so I tapped a smaller imperial socket on the head of the bolt and tried with that. put an extension in and my breaker bar. tried to undo it. and ended up twisting the 1/2 drive extension off. the square end where it went into the socket sheared.

Now I am stuck. no idea what to do. i have 3 left that I have not even touched and one has a socket stuck on it that I can't get off with a bit on an extension in it.

And no its not a cheap extension. its a really old sidcrome. had it for years.


So now, do I drill a pilot hole down the head of the bolt and try drilling the head off. or try another extension, when I get the extension bit out of the socket. I was gonna drill into it and thread a tap in an pull it out.


Any ideas would be apprieciated.
thanks

[Rens]

You can buy a special set of sockets that have a tapered spiral inside them that cuts into the nut as you try to loosen them . Made by Irwin tools , i have a set but not at home with me. I used them to remove two bolts out of the starter motor on a 350 Chev out of a boat that had been sittting in water for a while and had eaten half the nut away. Works like a champ.

Here's an example of the kit
Irwin Bolt Grip Remover 5PC Base set 394001: Amazon.co.uk: DIY & Tools

[TERRA Operative]

+eleventy one to the above. Those things are magic, like real Harry Potter magic, they have saved me a few times. They grip harder as you wind the bolt out.

[Sam_Q]

isn't a rattle gun always a better option than a breaker bar?

[thechuckster]

not really, all it does it make the process of rounding off the stuck bolt head an almost instantaneous process - rather than something you do over several seconds despite the voice in your head saying hey, isn't this is a bit too bloody tight?

[oldeskewltoy]

not sure how many 4AGEs are in your area of the world... but in the USA, a 4AGE can be had for a few hundred $. Don't bust your ass, and numerous tools, it might be time to spend an hour searching for another

[Sam_Q]

not really, all it does it make the process of rounding off the stuck bolt head an almost instantaneous process - rather than something you do over several seconds despite the voice in your head saying hey, isn't this is a bit too bloody tight?

I disagree, the whole concept of an impact drive is it undoes the bolts with shock loads, this means it's a sudden even force which is more likely to undo something than just strip it. This applies in particular to anything with an internal hex type head.

[wiso]

shock loads worked, I don't have an impact gun. I got the sheared head of the extension out by drilling into it and grabbing with a tap, then removing. put a new extension in and tried again. put my breaker on it then jerked it a few times and heard a crack.

so all good. issue is I had to fully remove each bolt to get the socket off that I hit on. so I hope I have not warped the head.


this is the 3rd head I have removed from an engine in 3 weeks and I can tell you. these bolts were way too tight.

[convertableTA23]

A trick my old man taught me was to put your breaker bar on the bolt and pull on it a fair bit and then hit the top of the socket/breaker area with a hammer. I think they even make a tool now specially to do this with. This and a piece of water pipe on my big breaker have never failed me, however i have broken 2 heads on my big bar, and they are good tools as well

I can assure you that anyone that is good on the tools can undo a bolt a impact gun can't, and can do up a bolt tighter than a impact gun can, well any 1/2" drive gun normal people will own.

[TERRA Operative]

I use a similar trick to above with screws that are feeling like they will strip out. Get a good screwdriver that's not rounded off, stick it firmly in the screw head and give it a few solid whacks with a hammer. The shock cracks the thread and the screw will come out easy. leave it nipped up and do the same to the rest. Once they are all cracked, then take them out. If you take them all out in sequence, the last one will be stuck in as all the force will be on that last screw as the part skews just a fraction.

Saved me a few times when I had a screw slightly corroded into a cast alloy piece.

[convertableTA23]

Yeah, that tool is called an impact driver