Broken head bolt, in the block, with the head on.

[Brad S.]

Slowly run that flute bit down and get it centered and LOCK the mag drill...then mill off the top of broken bolt

Next with a FLAT broken bolt in hole, the KEY is its FLAT you can now take your LH drill bit and run it down the hole and begin to work out that bolt by drilling dead centre.

If you have to you can use an easy out however it could invariably break to

Al

I do have some easy outs but read some threads about those breaking. Thats kinda why I went with left hand drill bits, they might be easier to get out if they break.
Plan for the worst, hope for the best.

 

[laserjock]

The easy out in my experience is a very questionable proposition. If they work, they are great. If they don't work (i.e. break) then you are in a real pickle.

My $0.02.

 

[riotwarrior]

The easy out in my experience is a very questionable proposition. If they work, they are great. If they don't work (i.e. break) then you are in a real pickle.

My $0.02.

This stems from a fundamental lack of proper use for the most part IMO

Basically most easy outs are smaller than they should be, and drilled off center..

Thus by using the four flute mill bit you clean off that broken top to a smooth surface, then you can center your drill accordingly, and use the largest possible drill and easy out! This significantly reduces the breaking problem.

Another method and this is one I have successfully used. Sharpen a regular drill bit with near 0 degree just a slight angle and back cut on it and very very slowly use it to mill top of broken bolt...problem is hand drill move about and a mag base drill setup won't move like a hand drill will. This would significantly reduce chance of ovaling or going into block threads etc.

JM2CW

 

[jaluhn83]

Make friends with someone who has an edm machine....

 

[Knuckledragger]

Take the head off. You will be able to reuse the head gasket since you have not finished your torque sequence and have not run the engine. You also do not say where the bolt broke? If it is at the end of the threads as we might expect, you may be able to get hold of enough to unscrew it with pliers.

On chasing and cleaning threads: after chasing the threads, it is best to flood the hole with WD40, PB Blaster or equivalent liquid then blow out all of the debris. If you suspect there is still stuff in the hole, dig around with a tooth pick or ice pick at the bottom of the hole and repeat the fill and blast routine. Cast iron, and especially this high nickle content iron used on the IDIs, machines easily, but leaves trace chips and dust that is nothing but trouble. Once the dust is created, you need to flush it out as completely as possible. Chasing threads creates this dust and will come back to haunt you in one or more ways: altered torque readings because of interference from dust and chips, galling (mechanical welding or rolling) threads, broken bolts, ruined female threads in the block necessitating helicoils. Not all of these things will happen at once, but any one is a royal pain that can be avoided by taking the time to clean out the threaded holes.

 

[franklin2]

and use the largest possible drill and easy out! This significantly reduces the breaking problem.

You have to judge what size will work best. Drill the hole too big and use a easy -out that is too large, it will tend to swell the broken bolt in the hole and wedge it even tighter. There is no exact science to getting out broken and stripped bolts. The more experience you get under your belt, the more successful you can be. I agree with the others though, I believe for the best success you need to get the head off and out of the way.

 

[jaluhn83]

Take the head off. You will be able to reuse the head gasket since you have not finished your torque sequence and have not run the engine.

Not sure what the book answer is, but it seems to me that the gasket would be crushed as soon you started torquing bolts and more likely than not is going to get somewhat torn up pulling it back off so I'd plan on replacing the gasket.

Cheap insurance to me.

 

[Brad S.]

You must be registered for see images attach

Ok, finally I get the pic uploaded. The top bolt is the subject in question. Bottom bolt is to compare.
Before I put the heads on I ran a tap down through each hole, then ran a bolt in & out, IIRC the threads on the bolts were completely in the block.
So being able to grab any part of the broken bolt, probably won't work.
But I can understand having the head off would help greatly.
If I can raise the head up far enough to slide the gasket out, without tearing or destroying it, would it work again???
I'll probably replace it, just curious what others have run into.

 

[idiabuse]

Good style bolt, Bad break.
Did you use washers and did you coat the washer and bolt head with oil as well as the threads?, No you cant slide the gasket out, it tears apart when lifting the head 90% of the time, What brand Gasket you used?

Javier

 

[Brad S.]

Good style bolt, Bad break.
Did you use washers and did you coat the washer and bolt head with oil as well as the threads?, No you cant slide the gasket out, it tears apart when lifting the head 90% of the time, What brand Gasket you used?

Javier

No washers, none on this motor anyway.
Dipped the bolts all the way up the threads with oil.
The gasket is a Victor Renz.

 

[idiabuse]

I am not positive but the IDIs I pulled apart all had washers.
When torqueing these bolts to 110lbs you need to oil the head
flange because that is a source of alot of friction and that may
of been why the bolt broke. Use Washers and oil them well.

Or buy studs.

Try a small magnet and see if the broke piece in the block is loose
and or wiggles. If it does it just may unscrew out easily.

Javier

 

[bbjordan]

Just a though...what kind of torque wrench are you using? The click type are notorious for going out of spec.

 

[G. Mann]

I did this ONE time and it worked..
Broke a head bolt on a Volvo engine. Nearly impossible place to get a drill. Thought on it for a while. Cleaned the hole with brake cleaner, blew everything out extra good with compressed air. Coated the threads of the broken bolt with clear shoe polish wax, several coats [as a release agent, I use it when bedding barrels in rifles so thought it would work, it did]

Mixed up a bit of J B Weld and put a fat dot on the very center end of the broken bolt and screwed it back in the hole by hand till I felt contact, walked away...

Came back 12 hrs later, put a wrench on the broken bolt and carefully spun out the whole thing...

The bolt hung over my toolbox for about 10 years as a reminder to use new head bolts...

Might work for you,,,, might not... Just thought I would share.


NSA ... The only government agency that actually listens ...

 

[Brad S.]

Just a though...what kind of torque wrench are you using? The click type are notorious for going out of spec.

I bought it some years ago, don't know right now. I think some standard parts place kind??

How can a person verify it???

 

[Brad S.]

I did this ONE time and it worked..
Broke a head bolt on a Volvo engine. Nearly impossible place to get a drill. Thought on it for a while. Cleaned the hole with brake cleaner, blew everything out extra good with compressed air. Coated the threads of the broken bolt with clear shoe polish wax, several coats [as a release agent, I use it when bedding barrels in rifles so thought it would work, it did]

Mixed up a bit of J B Weld and put a fat dot on the very center end of the broken bolt and screwed it back in the hole by hand till I felt contact, walked away...

Came back 12 hrs later, put a wrench on the broken bolt and carefully spun out the whole thing...

The bolt hung over my toolbox for about 10 years as a reminder to use new head bolts...

Might work for you,,,, might not... Just thought I would share.


NSA ... The only government agency that actually listens ...

Thats really good, think I might try that