Would freezing a stuck pre-chamber make it easier to pull out?
 

Unfortunately I have little experience with freezing parts to remove them. However, I have noticed with stuck Bolts and so on that heating them beyond a heat they would normally be subjected to even if you let everything cool back to room temp seems to have a good chance to loosen them. Whatever expansion and contraction goes (movement) seems to help.

With the pre-chambers in a Cylinder Head it would be tough to heat them beyond a heat that is normal for them but I think you could dump some Dry Ice inside the pre-chamber or use that freezing spray.

One would think that shrinking the O.D. away from the carbon build up between the head and outside walls of the pre-chamber by freezing it would loosen it some even if you let it warm back up.

Please comment.

It might upset any bond to some degree. On the other hand this part is a force or interference fit so you probably need to do some calculations with the co efficients of expansion and contraction of steel.

My thought is you may not get enough retraction with out going to something like liquid nitrogen. At the same time it would not hurt anything to try dry ice for example.

Using thermal upset as an aid in getting things apart or together is well established. I am just not knowledgeable enough about it.

For example it is a well established local practice to turn the area around a brake bleeder screw red hot. Quench it with a wet rag. or water. Do it two more times and that bleeder screw will move. Doing it only once is very risky. Twice less so perhaps . As the saying goes three times seems to be the charm. A part of life in the rustbelt.

It ain't going to work and is expensive. The temperature delta is small to make the coefficients of expansion, in this case, contraction, to work in your favor. I can heat any part to 1000C easily and very localized. Try it with liquid nitrogen, very expensive, and you only get to -273C.

Yes, where you can heat something and keep the surrounding area from heating.. it crushes the corrosion and makes room for penetrating fluid to get down in there...

What method or tools are you using right now which are not working ?

Do you have access to a tank of Nitrogen or Argon ?

^ this. freezing is silly. its cheaper and easier to heat parts to achieve a temperature delta. even more so these days with nifty tools like the "mini ductor" induction heater.

I am not having the stuck pre-chamber issue. However, another member is.

I was thinking Freezeout or Dry Ice. I don't think either are expensive.

The member has the Aluminum Cylinder Head off of the Engine.

I don't believe the pre-cambers could be sufficiently heated with a propane torch.

Welding/cutting torch would be rather generate enough heat but using it is questionable and it is not something the average person has in has garage.

I am too fumbley to use Liquid Nitrogen as I would likely end up with it on myself.

I am not having the stuck pre-chamber issue. However, another member is.

I was thinking Freezeout or Dry Ice. I don't think either are expensive.

The member has the Aluminum Cylinder Head off of the Engine.

I don't believe the pre-cambers could be sufficiently heated with a propane torch.

Welding/cutting torch would be rather generate enough heat but using it is questionable and it is not something the average person has in has garage.

I am too fumbley to use Liquid Nitrogen as I would likely end up with it on myself.

If one wanted some Dry Ice what type of place would sell it?

What type of puller is not working at this time ?

Here is the thread.
http://www.peachparts.com/shopforum/diesel-discussion/391789-fighting-wvo-residue-prechambers.html

The person is using a Bicycle Hub Puller attached to a Slide Hammer with a 5 pound weight. The Cylinder Head is not on the Engine.

When I faced the above problem in a parking lot with just the Cylinder head one of us stood on the Cylinder Head while the other worked the Slide Hammer and the Pre-chambers came out. However, the member in the thread is not having the same luck.

My local Nob Hill grocery store sells dry ice.

relatively, they are. spending dollars to drop the temp by tens of degrees, vs. spending pennies to raise the temp by many hundreds of degrees.

not propane, use mapp. mapp burns *much* hotter and is perfect for those times when propane isn't enough. engine blocks, cylinder heads, and other large heat sinks respond better to mapp.

Yes, if.
 

If you chilled it with dry ice then applied heat the radical change would stress the bonding between the individual parts.

Um... liquid nitrogen is nowhere close to -273C... that would be absolute zero... maybe .273F is what you meant?
Your point is still valid though... heat is much larger differential possible.

Nitrogen THREE times as cold as DRY ICE
 

But heat applied to the precombustion chamber pushes outward....which is fine for threads needing the corrosion to be crushed.. but once that does not work...
hopefully chilling will pull it away from the head....
but I am for the nitrogen because with the head off the engine since it can be applied for an extended period of time.. and is three times as cold as dry ice...(minus 320 compared to minus 109....)nitrogen might require some kind of gas routing ' fixture' ....to get it into and back out of the closed loop efficiently.
Whereas the dry ice will be a process of reinstalling the ice...


From WIKI...
'''''(-346°F and -320.44°F). Below 63 K, nitrogen freezes and becomes a solid. Above 77.2 K, nitrogen boils and becomes a gas. Since it is obtained from the atmosphere, liquid nitrogen is inexpensive and is rarely refrigerated.'''''
'''''Dry ice is frozen carbon dioxide. A block of dry ice has a surface temperature of -109.3 degrees Fahrenheit (-78.5 degrees C). Dry ice also has the very nice feature of sublimation -- as it breaks down, it turns directly into carbon dioxide gas rather than a liquid.''''''

YES. Freezing will work, depending on where you are...
 

IF you are located in Mars as the temperature delta will be bigger than heating. Liquid nitrogen will chill down to -210C. Absolute zero will be -273C. It is all a fool's errand.