Head Removal

[Jim Becker]

How any penetrant is expected to work on a thread that "supposedly" sealed to prevent antifreeze from leaking out is beyond me! . . .

If a sealer had been used, the bolt is much less likely to be stuck. Rephrasing, stuck bolts are less likely to have been assembled with sealer in the first place.

[goxu1]

The only 2 bolts to come out were on the manifold side.
I don't think these go into the water jacket , right ?
If that's the case , it might be safe to assume the rest are stuck due to rust on the bottom of the bolt

I cut the heads off all the bolts sticking up. I'd been using an impact on them for weeks and getting nowhere
Next step is to weld a nut on a couple and see what happens.
The 4 or 5 that broke off close to the block have about 1/8' still sticking up which is better than below the deck I guess.
If welding a nut doesn't work , then I'll make up a drill guide that drops into the hole in the head and go from there.

[indy61]

Looks like you could thread the longer ones and double nut if you have a tap and die set. The short ones that stick a little above the deck will need a nut welded on them.

[Stoffregen Motorsports]

I mentioned before that welding a nut onto it can case harden the bolt, so if the nut breaks off, you may have a hell of a time trying to drill it. If you do weld a nut on, let it cool, naturally and completely before trying to remove it. Don't quench it.

On the longer ones, I would quench them and try immediately after quenching to remove them. If the nut breaks off, then try again and let them cool naturally.

[goxu1]

Looks like you could thread the longer ones and double nut if you have a tap and die set. The short ones that stick a little above the deck will need a nut welded on them.

If they are rusted in like the ones that snapped off at block level , won’t “double nutting” them do the same ?

[indy61]

If they are rusted in like the ones that snapped off at block level , won’t “double nutting” them do the same ?

You can try to move them in both directions now. If you get any movement at all they should come out.

[SamsFarm]

If they are rusted in like the ones that snapped off at block level , won’t “double nutting” them do the same ?

Good chance of that. Trying to thread them to double nut seems counter productive when there are tools like pipe wrenches, stud removers, vice grips, and the weld the nut trick available!

I think in past posts, that you don't have a acetylene torch. ???

Not saying you should run out and buy one, but maybe borrow one.

I would heat the screws up till they glowed, let them cool, then try a pipe wrench on them.

If I did not have the torch, I would probably still try the pipe wrench. Seems there is not much to loose at this point.

At this point if you have to drill them out, well you have to drill them out, and might as well get it over with.

However the weld the nut trick might put enough heat into it to break the rust bond

[Matt Kirsch]

If the bolt heads did actually break and weren’t cut, then I agree with Gary. May not be a problem. Welding a nut to the ones that won’t come out would be the next thing to do. But I will offer my opinion that penetrant does nothing in a case like this. It won’t get to the threads.

The ones that are long, had the heads cut off.

The ones that are short, twisted off.

I agree that penetrant is a waste of penetrant at this point. I would be making a trip to Tractor Supply to get a pound of cheap 5/8 nuts, and getting out the welder. After I learned that weld-a-nut trick and first used it to get the broke off bolts out of the final drives on my old Cub Loboy, I have been hooked. IF there's any stub sticking out at all, sometimes even if there's a bolt head still there, I quit wasting time and weld on a nut.

Now you might be able to use a Jimmy Diresta trick if you lack a welder or an oxygen-acetylene torch. He uses multiple Bernz-o-matic propane torches focused on the same spot to get the BTUs to heat metal to red hot. In lieu of a welder, I would concentrate 2-3 propane torches on each bolt at the block surface, get the bolt red hot, then let it cool. Then latch on with a pair of vise grips and give it a try.

[tnestell]

I don't know if burning them out with an oxy/acetylene cutting torch would work here. I have burned out broken bolts out of cast iron and chased the threads with a tap. The thread were always left intact in the few that I did.

[Gary S.]

Load her up and take her into town. Someone in Sydney must have a EDM machine

[Crimson Tim]

Don’t mess with vice grips.
If it’s time to apply some brute force, use a pipe wrench. As long as it’s facing the right direction, it’ll bite right in and won’t slip. The bolts are already toast, so it won’t matter that they get chewed up in the process.
I would use heat first, though, to weaken the bond.

[SamsFarm]

Load her up and take her into town. Someone in Sydney must have a EDM machine

Thats funny!

Have you ever run a EDM?

[Gary S.]

No I had heard they are used to remove broken taps and bolts though-

Metal disintegration machining
Several manufacturers produce EDM machines for the specific purpose of removing broken cutting tools and fasteners from work pieces. In this application, the process is termed "metal disintegration machining" or MDM. The metal disintegration process removes only the center of the broken tool or fastener, leaving the hole intact and allowing a part to be reclaimed.

[52DAVE]

To remove a broken bolt on the intake of my 67 Buick I was told to heat the casting up good and hot then take a candle and melt some of the wax on the bolt. As the casting cools the wax will be puled down into the threads. Once cool weld a weld nut on top of the bolt. It worked like a charm.

[SamsFarm]

No I had heard they are used to remove broken taps and bolts though-

Metal disintegration machining
Several manufacturers produce EDM machines for the specific purpose of removing broken cutting tools and fasteners from work pieces. In this application, the process is termed "metal disintegration machining" or MDM. The metal disintegration process removes only the center of the broken tool or fastener, leaving the hole intact and allowing a part to be reclaimed.

Most of your basic edm machines found in a tool & die / injection mold shop has a magnetic chuck in a tank on the machine. Most common use is for complex shapes not easily made in other forms of machining

The tank is needed to keep the workpiece submerged in a special oil.

Generally a electrode of carbon (sometimes copper and carbide) is used.

The oil is needed to flush away the particles and also to keep the spark contained in the oil.

If the gas produced by the arc mixes with the sparks in the open air, it makes a fire.

Finding a edm big enough to work the block of a Cub engine while probably not impossible, but probably prove really hard to find. $$$ per hour would probably prohibitive!

That said there are some portables made, could be rigged up to on a cub. Whether there is one close by???

Second thing to consider is a edm is not the fastest way to go, but probably the most expensive. The process can be really slow!

Now if Mr goxu1 had broken taps in his block, then that might be his only option. But with his broken head screws, drilling would be much easier if it comes to that.