[Bill Eveland]

I'd try letting it soak in on pb blaster for a few days. Too bad you couldn't get a 2 jaw puller on the broken head bolt but it's not centered .The head is stuck on the broken bolt not the block that's why the head bolt broke off because it won't turn in the head

Unless your comfortable drilling the bolt I'd let the machine shop handle it before any damage is done if none of the methods will get it loose.

[gtofreek]

After heating the broken bolt/exhaust port nice and hot[not sure you'll get it red hot, I really doubt it], spray it with PB Blaster, then try prying as suggested.

[67cruiser]

9 times out of 10 the head gets hung up on the alainmant pins. there are one on each end.
Mr Vaught is correct, put a breaker bar or pipe thru intake port& yank upwords.

[J.C.you]

if it were mine and the pry bars would not work, I would put two long headbolts in each end, under the valve covers, and make sure to leave them loose. Attach a chain to each end of the head and suspend the assembly in the air with a hoist. Get the rosebud out and heat the area around the seized bolt, and let the weight of the motor/engine stand do the work. A dead blow hammer should help also.

[hurryinhoosier62]

Originally Posted by beemergary

Then jap with cold water-The expansion and sudden cooling(contraction) will break the rust loose.

NEVER do this! The iron in the head WILL CRACK. This is called "shock cooling" and should ALWAYS be avoided.

[hurryinhoosier62]

Originally Posted by gtofreek

After heating the broken bolt/exhaust port nice and hot[not sure you'll get it red hot, I really doubt it], spray it with PB Blaster, then try prying as suggested.

If PB Blaster doesn't work, contact Kano labs in Nashville, TN and order some Kroil. Heat the remainder of the bolt (NOT red hot), apply the Kroil, let sit overnight and remove the head as Tom suggests.

[Pontiac Fool]

Most good machine shops have a tool called ELECTRIC DISCHARGE MACHINE (EDM) that doesn't require drilling & an easy out. It uses electricity to dissolve the bolt without any damage to threads or other parts.
A friend broke a thread tap off in a tooling die & took it to the machine shop to drill it out (couldn't take the chance of damaging the threads with a hand drill).

Heating should work but I would never pry on it wile its really hot if there is a chance that your not prying straight up. Because the soft hot cast iron will distort. Could end up with a oval hole or worse bent or broken head surface. Its easy to over do something you never tried using a generalized post as instructions.


Joe

[NeighborsComplaint]

This may sound like a silly question, but have you tried a black iron pipe pry bar in the intake port and pushing the head towards the outside of the car?

You may have to pry at one end, drive a wedge in and pry the other end, slip a wedge in and walk the head up the broken bolt that way. Keep the head gasket between the wedge and the block deck surface.

[61-63]

Originally Posted by scld1354

Point / aim the flame down the hole so it hits what's left of the bolt. The head will sink a lot of heat, but it ok if the head get hot in the process.

Again what he said. Aim the point of the flame at the end of the bolt down in the hole and get it cherry red. Then let it cool. Then try to remove the head. Do this repeatedly and the head will eventually come off. As someone else seconded DO NOT throw cold water on it while it is hot the head will crack. It may end up cracking anyway before you get it off but chit happens.

[Will]

Ditto the heat suggestions. Get an oxy-acetylene torch, a regular propane torch isn't going to get it hot enough.

Get it as hot as you can, glowing if possible then let it cool completely before trying to pry on it. Might take several heat cycles but it *should* break loose.

Do you trust yourself to hold a drill straight & steady? Try drilling out the center of the bolt. If you drill enough of it out it may weaken enough that it'll break off when you pry on the head.

[Sirrotica]

Without seeing a picture of the location of the head bolt I have no idea if you can use a brass drift on the boss surrounding the broken bolt. Shocking the surrounding casting with a hammer and drift is the easiest way to loosen a rusted shaft/bolt inside of a casting. Even beating on the ends of the stuck bolt is not as efficient as shocking the surrounding material is. Trying to drive on the ends of the stuck shaft actually wedges the rust in tighter than it was originally. If there is rust pockets on the remaining bolt the rust will make a very efficient lock until it's pulverized. More than likely you have that situation now and the rust needs to be broken up so it will no longer hold the 2 parts together.

If your familiar with king pins in older cars and trucks this is a sure way to remove a rusted king pin in a beam style axle and should work as well in your situation. Believe me it works better than heat or any type of penetrating oil. You have to use common sense doing this, but I know for a fact if you can shock the surrounding metal with sharp hammer blows the rust will break up and it will come apart surprisingly easy.

My father who was a mechanic most of his life (He would be 99 today, as it's his birthday, passed 7 years ago now) showed me how to remove king pins using this method when heat and penetrating oil had no effect on the pin stuck in the beam axle. I've used the method on many things over the years in similar situations.

Flathead V8 fords had the same type problems with aluminum heads on a studded block, my father told me you could remove all the head nuts and start the engine and it would run the same as if all the nuts were still on. Running the engines would not loosen the cylinder heads on their studs. He told me that about the only way to remove the heads was to get 2 wide cold chisels and drive them in between the head and the block on each end of the block and they would finally break loose. Of course the heads needed to be replaced because of the soft aluminum gasket surface would be torn up, however if you had to get the head off, this was the only way. I'd use this as a last resort being the cast iron is much harder than aluminum it may not harm anything, no way to know for sure though.

[AZ64GP]

Thank you for all the suggestions. I haven't tried using a large iron pipe in the intake port of the head, but I've really worked a large pry bar in the exhaust ports. I don't have a large iron pipe, but I have a large pry bar (it's got a handle handle on one end and is about 3' long). I've tried lifting up on the bar as quickly and strongly as I could, as well as pushing up on the bar, while another person swings a baby sledge hammer up on the pry bar. None of these have worked to free the head (as of yesterday before I wrote this post). I am able to pull up hard enough on the pry bar in the exhaust port that I lift the engine and engine stand up partially off the ground. I soaked the bolt hole a couple times since yesterday morning with PB Blaster and it seems to be absorbing into the rusted hole where the remainders of the bolt is in the head (unless it is evaporating). I have an easy-out set, but I don't trust my hands at drilling out the bolt with the easy-out and I think this broken bolt is rusted past that point.

I don't have access to an oxy-acetylene torch, but do I'll try it with a propane torch. I'll try that in a cycle (I definitely won't be dousing it with cold water) and letting the bolt hole and head cool down before I try it again. Hopefully that will help. If the PB Blaster doesn't work, I'll try Kroil too.

I don't have access to an engine hoist (I had to drive out of town and borrow one when I pulled the engine) and the engine is out of the car, so using a hoist to lift the engine and let the weight separate the head from the block will be difficult. I may have to try it though if heat or penetrating oil doesn't work.

Thanks again for all the suggestions and I appreciate the help!

[Ed Fitzgerald]

Diesel fuel will dissolve rust as well as just about anything. Put some down the bolt boss and let it sit for a day or so then blow it out with air and repeat, as far as heat goes when you heat the bolt it grows larger in the boss. Conversely when you heat the casting the hole gets smaller as the metal expands into the hole. Ed

[lust4speed]

If you want to insure that the head and the block survive the removal this might be a good time to call in a professional. An EDM bolt removal specialist can remove the bolt with absolutely no damage to the head or the block. You should be able to locate the business either through a local machine shop or probably on the internet. In our area it is a one man operation that has a weekly route covering any shop that has called him. Last time we used him was when a friend broke off an easy-out trying to remove a timing cover bolt broken off flush in the block. The friend managed to drill the bolt and then break off the easy-out flush with the surface. The EDM bolt removal guy charged $75 and the bolt hole and threads looked virgin when he was done. EDM is Electric Discharge Machining.

[dmac]

Instead of lifting the head with the pry bar, try to 'unscrew' the whole head using a long extension on your prybar. If it just that one bolt. it will either unscrew out of the block, or snap off. In other words, twist the head instead of lifting.

If pistons and crank are still in, I would attach a starter/flexplate and try to pop it off with spark plugs in on that side only.

[gtofreek]

Originally Posted by Ed Fitzgerald

Diesel fuel will dissolve rust as well as just about anything. Put some down the bolt boss and let it sit for a day or so then blow it out with air and repeat, as far as heat goes when you heat the bolt it grows larger in the boss. Conversely when you heat the casting the hole gets smaller as the metal expands into the hole. Ed

Actually, holes get bigger when they heat up. Just like about anything else. It shrinks in diameter when cold.

Measure any cylinder bore when cold, then heat it up and remeasure. It will be bigger. When I hone blocks, just a 10° drop in temp will shrink the cylinder up .0005" or so.

[lust4speed]

try to 'unscrew' the whole head

Don't forget that the two dowel pins will prevent any attempt at unscrewing the head from the block.

[61-63]

Propane won't do it you need oxy/acetylene. Sounds like you need to take it to a machine shop they shouldn't charge you much to get it off.

[AZgoatguy]

I don't think anyone has suggested using Muratic Acid (swimming pool acid) but it may be worth a try. Here in Tucson a long-time GTO drag racer and speed shop owner told me that he uses muratic acid to cleanup and loosen rusted engine blocks and heads. He would create a tub using cinder blocks and then line it with 6mil black plastic sheeting and immerse the block/heads in a diluted solution of the acid. He said it really did a good job of freeing stuck pistons, etc. Since you've got a recess above the broken bolt that would hold a quantity of the acid solution you could let it soak down and maybe do some good in dissolving the binding rust. Because this is a small, confined space I think a solution of at least 50/50 would be okay, maybe even go a bit stronger. But before you try the acid I would tip the engine to the side and use a strong blast of Brake Clean to flush out all residual petroleum lubes you've put in there so as to have it as clean as possible. Good luck. We're all rooting for you!!!
Gary in Tucson

[AZ64GP]

Originally Posted by AZgoatguy

I don't think anyone has suggested using Muratic Acid (swimming pool acid) but it may be worth a try. Here in Tucson a long-time GTO drag racer and speed shop owner told me that he uses muratic acid to cleanup and loosen rusted engine blocks and heads. He would create a tub using cinder blocks and then line it with 6mil black plastic sheeting and immerse the block/heads in a diluted solution of the acid. He said it really did a good job of freeing stuck pistons, etc. Since you've got a recess above the broken bolt that would hold a quantity of the acid solution you could let it soak down and maybe do some good in dissolving the binding rust. Because this is a small, confined space I think a solution of at least 50/50 would be okay, maybe even go a bit stronger. But before you try the acid I would tip the engine to the side and use a strong blast of Brake Clean to flush out all residual petroleum lubes you've put in there so as to have it as clean as possible. Good luck. We're all rooting for you!!!
Gary in Tucson

Thank you Gary, and to everyone else for the replies! This is my first car I've ever restored, so everything I'm doing, I'm doing for the first time. I've gotten a lot of help from friends, books, and this forum.

I've been spraying PB Blaster down the hole for the past few nights, but I haven't had a chance to pull up on the head yet to see if that has helped. I've researched EDM, but I have only found one place in the Phoenix area that looks like they can help. Most of the places I have found are engineering and design labs that the aeronautical industries use. I don't have an oxy-acetylene torch, and from what I have read, a propane torch isn't going to do it. I'll continue to give the PB Blaster a try, and if not, I'll clean out the bolt hole and try the muriatic acid. If that doesn't work, I think I'm going to have to send the block with the head attached to a machine shop and have them figure it out. I'll update this thread when I have a chance to work on the engine again this week and let you know what happens. Thanks again!

Chris