Cylinder head to block studs, seized. Lessons learned…

[Colin Lindsay]

Compressed air in through the spark plug holes?

Failing that, go in from underneath - crank and pistons out from below then a large wooden drift up through the piston chamber? Even two, three four or more wooden blocks of suitable length and diameter, one into each chamber then lower the engine down onto them so that the head takes the weight of the block which might just drop off below?

[Wagger]

As all of the valves are closed, pour diesel mixed with ATF down the plug holes with engine tilted away from the plug side. Replace the plug and leave overnight.

Then use a large wooden block and a club hammer each side. This may even 'Unseize' the pistons.

[Pete Lewis]

the loads applied when the con rod is getting up to tdc is immense and the rope trick will often bend the conrod very easily   dont do it 

Pete

[Stratton Jimmer]

On 15/12/2021 at 15:52, dougbgt6 said:

The odd thing is there was no rust at all, the studs had simply been put in by a gorilla. 

We used to joke in the RAF that you should use "standard" torque for every nut and bolt... Tighten it till it shears then back it off two flats!

[JohnD]

1 hour ago, Pete Lewis said:

the loads applied when the con rod is getting up to tdc is immense and the rope trick will often bend the conrod very easily   dont do it 

Pete

Indeed, as I know to my cost:

 

Roger, If you can 'crank up the voltage' on your welder, then IMHO that will be better than your neighbour's gas axe, as the heat will be concentrated on, and in,  the stud.

Have you tried 'Innox DeBlock' a German penetrating oil, that I have found most effective, although not on seized head studs?

John

[Roger]

52 minutes ago, JohnD said:

Have you tried 'Innox DeBlock' a German penetrating oil

Thanks John, a picture says more than a thousand words! No, I haven't but that penetration oil seems to be very interesting! Never seen it before. It comes in two versions apparently. One version that also cools down the part to minus 45 C. Is that the one you have used?
Deblock Ice

I plan to go to Sweden in March, I will see if I can find it there. I hope that such a low temperature will not make the stud too fragile and snap. But it's worth a try, I have tried everything else. I did replace the phosphoric acid with citrus acid as you suggested earlier in this thread, but the acid don't penetrate all the way down. Shock-freeze to minus 45 might help. At least it sounds very effective in theory!

/Roger

[JohnD]

Not tried that brand, but I have tried 'shock-freeze' sprays before, with no success.   The effect of strong heating by welding, followed by some of the Deblock Ice, to expand then contract the stud might be interesting!   But as you say, allow it to get back to room (or Åland!) temperature before applying the breaker bar again!   I'd also strike the stud, hard, with a heavy hammer, to apply some physical shock as well.  This could be done hot.

In my experience it is always that the stud is seized to the head, not to the block, by corrosion.    If rust dissolving liquids will not get into the stud hole, then some putty, or another mouldable compound that will stick to the head, can be shaped into a cup around the stud, leaving a space which may be filled with small volume of penetrant.  This will allow it time to soak in, and then topped up until no more goes in, ensuring that the hole receives as much as possible.

John

[Roger]

1 hour ago, JohnD said:

I'd also strike the stud, hard, with a heavy hammer, to apply some physical shock as well

You can rest assured that this corrective action has been implemented. Properly. With passion and precision. I know perfectly well that talking to dead things won't help. But I have to admit that I have had long conversations with these studs as "physical shock" was given. I hope that my neighbours haven't seen or heard me. In fact, these studs gets a proper whack with a 1,5 kg hammer almost on a daily basis, every time I go to my garage.

[PeteH]

One of the "suggestions" that was passed to us "sprog" apprentices, when faced with recalcitrant fasteners, was to tighten the fastener first, the theory being that, in further stretching the Bolt/Stud you broke the "binding".

pete

[JohnD]

33 minutes ago, PeteH said:

One of the "suggestions" that was passed to us "sprog" apprentices, when faced with recalcitrant fasteners, was to tighten the fastener first, the theory being that, in further stretching the Bolt/Stud you broke the "binding".

pete

Absolutetly, Pete!    And, in 'easing' a seized fastener out, work it to and fro.    Another tip is to listen to it!    If it starts to squeal, then it is about to break!    Screw back in a bit, apply more penetrant, wait, try again!

[ahebron]

Electric induction heater on the remaining stud.
I do not know what you have available on Aland or what is possible to buy from Ebay, Amazon or Aliexpress but they are pretty good at localised red hot heat.

Even the 12 volt kit ones will get a head stud glowing.