Removing Stuck Heads

[Ken/Alabama]

About a year ago a friend called me and said he had a couple flatheads in his shop that had been there for years and were in his way and he would bring them to me if I wanted them so I said absolutely. He brought two 37 21 stud engines and a third was a 59L with offy heads . I could tell that someone in the past had tried to remove them because all the nuts were gone and I could see some marks from failed attempts. So I sat it in the floor and would soak the studs with Kroil oil . I put it on the engine stand yesterday and pulled the oil pan. To my surprise it’s very clean and has a Merc crank in it that still .010/.010. I pulled the crank out and five pistons out from the bottom. It has a set of Jahns four ring 3 3/8” pistons. I put a large block of wood down in the cylinders from the bottom to try to drive the heads off. They never budged. Next I’m thinking about welding nuts on the studs to see it the heat will break them lose. Anyone have any other suggestions. ? Thanks

 

[38 coupe]

I don't have any ideas for head removal without risking breaking the heads. However, I have a question, are those floating rod bearings 1.999" or are they 2.139"? It is unusual to have floating rod bearings on a Mercury crankshaft unless it has been stroked 1/8 inch and uses prewar rods. If you don't have an easy way to tell crankshaft diameter or stroke, what are the rods marked?

 

[Ken/Alabama]

2.139 .010. Has 99A rods in it. I put a micrometer on the crankshaft and it’s dead on .010 under. Rods and mains.

 

[1952henry]

I’ve heard of using a hole saw that will fit over the stud. There are swedge cutters for removing brake drums that might work better.

 

[Lawson Cox]

Bonito.

 

[Vics Stuff]

I would not weld nuts on the studs. I would dig out your rose bud torch on your oxy acetylene torch and heat each stud then quench with ice cold water. I would do every stud at least twice , then try bumping the heads again.
With the torch treatment , you may be able to remove the studs.
Vic

 

[aussie merc]

take your time 2/3 auto trans 1/3 kero or diesel set the engines so this will stay on the studs and soak in heat studs and drip in takes time and patience dont think this will happen overnight [took me 3 weeks to get one head off doing this twice a day] also liberal application of the use of an air hammer the rapid vibration often works where a thump of a dead blow wont but above all BE PATIENCE

 

[Tim Ayers]

I'm a big fan of the induction heat tools. Unlike a torch, they concentrate the heat to only the part inside the electrode. This may help break the bond of the aluminum heads have made to the studs since the stud will get hot, expand and then cool vs. both the head and stud getting hot.

 

[Karl Wolf]

Try putting nuts on the studs, loose. Take a punch to hit them sideways, all directions.
This may break up the corrosion. Use oil. I like your block of wood from the bottom.

Karl

 

[signsup]

I have never had to resort to this method but have seen videos where they feed some 1/4" cotton rope through the spark plug hole an several cylinders and then bump the engine over using the pressure of the pistons to push the head off.

 

[Brendan]

I have never had to resort to this method but have seen videos where they feed some 1/4" cotton rope through the spark plug hole an several cylinders and then bump the engine over using the pressure of the pistons to push the head off.

that is a bad idea, also he pulled the pitons,

 

[jrvariel48]

I welded the threaded part of a spark plug to a piece of 3/8" threaded rod and made a crude slide hammer out of it. You gently slide the weight upwards to a washer and nut at the top end of the threaded rod. You can start in any of the spark plug holes and move the assembly to other holes until it pops loose. Works perfect every time

 

[FlatheadTed]

The one we just did in the car we locked two nuts together on a stud and got the stud out ,then used a concrete stud expanding bolt in the hole with a attached dent puller , Looking at your photos try a 15 "length of hard wood on the head shoulder on the manifold face ,lay into it with a sled hammer ,Ted

 

[Ken/Alabama]

The one we just did in the car we locked two nuts together on a stud and got the stud out ,then used a concrete stud expanding bolt in the hole with a attached dent puller , Looking at your photos try a 15 "length of hard wood on the head shoulder on the manifold face ,lay into it with a sled hammer ,Ted

I gave up trying to remove the studs. I rung two off and they broke flush with the head and not the block so that tells me the studs are seized to the heads.

 

[Tim Ayers]

I gave up trying to remove the studs. I rung two off and they broke flush with the head and not the block so that tells me the studs are seized to the heads.

Are you trying to save the heads if possible? If not, may be time to use a zip wheel and starting making slices 7/8th the way through. Eventually they will crack apart.

 

[Ken/Alabama]

Are you trying to save the heads if possible? If not, may be time to use a zip wheel and starting making slices 7/8th the way through. Eventually they will crack apart.

Yes, trying to save the heads if possible.

 

[Tim Ayers]

Yes, trying to save the heads if possible.

I've heard of guys running a hole saw bit over and down along the studs. I forgot what size it would off hand, but I believe someone makes a thin walled bit for this purpose.

 

[Ken/Alabama]

I've heard of guys running a hole saw bit over and down along the studs. I forgot what size it would off hand, but I believe someone makes a thin walled bit for this purpose.

I’ve heard of them but have never been able to source one. I think a hole saw would be too thick and it would take a deep one . I’m wondering if i could find a hole saw with the correct ID if the OD could be ground to make it thinner.

 

[TomC750]

I welded the threaded part of a spark plug to a piece of 3/8" threaded rod and made a crude slide hammer out of it. You gently slide the weight upwards to a washer and nut at the top end of the threaded rod. You can start in any of the spark plug holes and move the assembly to other holes until it pops loose. Works perfect every time

This idea looks like a winner, not that I have ever been faced with this problem with aluminum heads, just the routine stuck cast heads.

 

[tubman]

Winfield or KDW or somebody used to make a tool just for this. I've only seen pictures, but maybe someone has one you could use. With the cost of aftermarket heads these days, it would be a shame to ruin those if they're in decent shape. Might be easier on the rest of the engine as well.