A stuck engine head

[boatminion68]

A stuck exhaust valve has forced me to take off the head. I've tapped the valve from the outside, put much MMO into the offending cylinder, and finally conferred with MM and I'm working on getting the head off. I removed the exhaust manifold easily and the head nuts came off without much difficulty. Here is my problem. I can not get the head off. I've tapped it, I've used a putty knife to get between the block and the head.

Is there a trick that I don't know about? How hard can I wack on this this. One thing to note is there is a stud that holds the thermostat housing that looks to be stuck. The other stud came out as I "tried" to unscrew the nut. See pictures. All the other studs look to be free. I just cant seem to get the head and block to separate.

Any and all help is appreciated,

Thanks
Boatminion

[ArtJ]

According to all the other posts I've seen regarding head removal, you are
doing it correctly. Just continue with the putty knife and hammmer all around the edges. Perhaps you need to use more than one putty knife
to work a couple of spots simultaneously.
and be persistenly patient. Do not force the head off any other way so as not
to damage the head..

There are some experts on this site who will give you additional advice,
but it amounts to persistence. Double check that you haven't missed
any bolts.

Best Regards

art

[ArtJ]

Have you tried freeing the stuck valve pushing with a allen wrench and mystery oil
thru the spark plug hole before attempting to remove the head? This
often frees up a stuck valve.

[hanleyclifford]

The stud at the thermostat is probably the sticky part now. If you can get that stud out the block the head will be easier to remove.

[boatminion68]

Head removal

All,

I've tried to push the valve down with an allen wrench and a home made tool to get a better angle on the valve. No luck.

The stud that is "stuck" concerns me. How do I get the head freed from the stud? I've tried balster but it does not seem to be doing anything... what are some ideas to unseat the engine stud?

When I'm getting into the seam between the head and block, should the old gasket be brittle? my gasket is hard.

[ArtJ]

You can put two head nuts on the stud and counter lock them on each other
with wrenches. Then you could put PB Blaster liberally around the threads
and gently tap on the stud. Repeat this for up to several days. Eventually
the stud will gradually come free. Otherwise it will have to be drilled out.

Check with others such as Hanley or Jerry to know how deep to drill
and make sure to centertap the stud and drill on center with a piece of
wood or possibly a socket as a depth gauge to prevent going too deep.

For now, I would use PB Blaster, or at least mystery oil or penetrating oil.
Some people have suggested using Automatic transmission fluid as
penetrating oil

Good Luck

Art

[ArtJ]

I would keep working with the putty knifes while coaxing the stud.
You could get lucky and get past the stud in the process of lifting
with putty knives.
Do a seach on head removal on this site for other suggestions on
coaxing the head free. I think once it get started you will need something
more than putty knives, but be careful if you use wedges or screwdrivers.
Definitely do not use them in the early stages so as to not mar the surfaces.

[roadnsky]

Here's a particular thread that seems relative to your situation.

http://www.moyermarine.com/forums/showthread.php?t=4022&highlight=head+removal

I agree with Art and Hanley's advice. It's likely the stud is holding you back.
I will say that if you can muster the patience, it is MUCH preferred to not have to go down the dark path of drilling studs () IMHO.

Here's a quote from our favorite Northern Brother about the "virtues" required for head removal...

"I think the stuckness is from the studs. There is a close clearance here, and little rust and goo sets up between the studs and the stud hole.
The guys are right, Don't use lots of force. you should worry at it like a puppy with a big bone.
Soak it with your favorite penetrating oil. I use WD40 for everything.
Just tap(not beat) a little here and there on non critical surfaces to loosen the rust a little, and pry with the putty knife.
Polish off the sharp edges on the putty knife first. The cast iron is soft and you can gouge it easily.

The head will still be stuck on the studs even when its up off the block.
Just take it slow and slide it up off the studs.
This is where we prove to the wife how patient we've become at our age.

Finesse,
Russ"

Hang in there and please do keep us posted...

[hanleyclifford]

Also try clamping the stud with vice grips and turning it out, not too hard unless we are ready to go the drill and retap route.

[lat 64]

I was going to chime in here, but it looks like I allready did. Ha!
Time is on your side.

Finesse,
Russ

[2dogsfishin]

Head puller device

Many Moons ago, someone much wiser than I told me about his secret A4 Head Puller. I made one and have been using it successfully since.

Get a piece of wide "U" beam steel, about the width and length of an A4 head, measure carefully and drill two holes at #1 & #4 spark plug holes, 3/8".

Then get some 3/8" all thread, drill out two old spark plugs for tapping the size of the all thread.

Break the porcilien (?sp), and drill and tap for the all thread. Screw a nut on the all thread, then screw the all thread into the tapped spark plugs

.Asuming you have removed the studs, replace at least 4 of them to the same depth so they extend the same length above the head and are located to hold the "U" beam evenly.

Place the "U" beam on the studs and screw the tapped spark plugs into # 1 & 4 spark plug holes.

Thread a 3/8" nut onto each of the all threads, spray a little torquing oil and pull them down gently, a little on each until the head lifts up.

So easy!

I have stripped out the threads in some real old rusty heads, but no problemo, move the puller and/or drill more holes over the # 2 & #4 spark plug holes and continue. Later you can install a spark plug threaded insert.

I will post pix of my head puller if requested. Also, since I have pulled my last A4 head, I will sell my head puller to some hardy lad for a reasonable sum + shipping from 32507.

Hope this helps.

Tom

[roadnsky]

I was going to chime in here, but it looks like I allready did. Ha!
Time is on your side.

Finesse,
Russ

Sorry Russ to steal your uh, thunder...
Certainly feel free to impart more *nuggets of wisdom though.
(*get it? Alaska... nuggets?)

[ArtJ]

I have seen posted numerous times,
warnings of any technique that may destroy spark plug threads

[lat 64]

Jerry,
No prob, I am flattered to be quoted.

2dogs, I 'm lost here concerning the studs. If they are all removed first, won't the head just fall off?
I always thought the problem with removing an A-4 head was the studs holding it down with rust?

Russ

[2dogsfishin]

Frozen north & humid south

In order to not damage the head or block by hammering stuff between them, I use this technique. Since 1967 I have pulled a few A4 heads and rarely have all the studs surrendered and even if they do the heads down here in the hot, salty south gain affection for the block. Like they are in love and don't wanna lego.

I do not allow my young, strong helpers to use the Snap-On Stud Puller as they are too strong and break the studs. I apply gobs of Aero Kroil for days, tap gently, then try to ease them out, but occasionally a 72YO can snap a stud.

Driving stuff between the head and block is not what I was taught to do.

Tom in Pensacola, FL Lat. 30 24.329N. GOM water temp is 90 degrees.