Really really frozen motor!

[OaklandF4i]

I have no more suggestions for freeing the piston than already mentioned.

My gut instinct is you may very well find the lower end in as bad a shape as the top. Acquired a YZ250 single lower end such poor shape from being left outside, that the growing corrosion inside between the crank and case actually put some tiny cracks in the cases (much like a growing tree under concrete.) In addition, if the crank is really frozen AND corrosion has built up around it between the case, whacking the piston hard and freeing it may only damage the crank, rod, and or case too as the force is transmitted to them.

I don't have a ton of experience with really old and frozen stuff. Just my limited experience. Based on that, I think i'd likely proceed with collapsing the piston if none of the above suggestions work in relatively short order.

Confident it could be done is such a way as to not destroy the crank and or rod as well. Really no reason in my mind not to proceed that way.

Just my opinion.

 

[seadog]

If you have a torch I'd go with the heat. On the outside of the cylinder. Aluminum has about twice the coefficient of thermal expansion for linear applications than does steel. Penetrant-time-heat-force, repeat.

 

[Dogfeathers]

Just thought I would give an update on the progress getting this very stuck engine unstuck.....NONE! Nada, zilch, zero!
I continue to go bang on the piston every three days with a mini sledge and piece of hardwood and still no movement at all.
I have taken some of the suggestions above. I have put muriatic acid in the cylinder and all I got was a bit of bubbling, probably from a chemical reaction to the aluminum, but it still did not seem to loosen up any of the rust or corrosion enough to get some movement. I then proceeded to use a oxy acetylene torch to get the cylinder/fins good and hot and did the hardwood and sledge routine again...Nothing!
I have since removed the muriatic acid and replaced it with vinegar and let it sit a few days and repeat with hardwood and sledge and still nothing. That baby is stuck!
I am coming to the conclusion that I may have to start drilling/sawing on the piston to get it to collapse and go from there. Trying to avoid such barbarism but am up against a wall.

 

[GottaRollWithIt]

Haven't read everything, but noodling on this a bit... This is a bike motor, meaning it's relatively small and light. Is there a reason you can't fill the crankcase up with penetrating catalyst? Even if the head is off, that'd submerge the crank/rods/underside of the piston.
If you're filling the cylinders with atf/acetone and none is ever displaced, then you're obviously not making any progress. Perhaps lubing from the bottom up will help..... and use of an Astro Big Nasty/air hammer...(which very well might thrash your rotating assembly)

 

[Maddevill]

How about some C4 ?

Mad

 

[ST Guy]

Possibly, if the engine is frozen that bad, it might not be worth fixing.

 

[Tom G]

I was also wondering, if you have to go to these measures to get the piston off and it still stuck, what is the quality of the engine/gearbox overall? Is it even worth any effort?

 

[Dogfeathers]

I did get the head off already,(but with a fight) and the combustion chamber was funky but easily salvageable. I pulled off the valve covers and all was well inside. Not set up and still oily with no corrosion or rust inside. That particular head brings $800-1000 on EBay so I am way ahead already.
The crank is already loose but may be junk, but transmission components and cases may be okay so I am going to forge forward. It was free so it is all gravy from here on. Will keep you posted.

 

[buellistic]

Pictures!,,,,

 

[seadog]

Wow! You are more patient than I am. I probably would have gone the; "I had to destroy the engine to save it" route.
Most of the stuff I work on is steel so it's gets up to Ducati Red temp to take it apart. You wouldn't have much left of the aluminum cylinder if you did that.
Maybe some type of shade tree electrolysis process?
Keep us posted. This is interesting.

 

[bpw]

Oven, then freezer, repeat a bunch of times and sometimes the expansion/shrink cycle will brake things loose.

I'm not sure a propane torch can get enough heat into a cylinder to make much difference.

 

[Dogfeathers]

Pictures!,,,,

I have a dreaded “pacbell” email account (at&t related) and there is some kind of cat fight going on between BARF and them so I cannot post pictures or do a lot of other stuff on Barf. Just a rusty corroded engine, you have seen them before and this one looks just like them.
And I don’t care to open up another email account just to post a few pictures. Post one picture, get 1000 spams, ....nah.:ride

 

[Dogfeathers]

Oven, then freezer, repeat a bunch of times and sometimes the expansion/shrink cycle will brake things loose.

I'm not sure a propane torch can get enough heat into a cylinder to make much difference.

I don’t think the whole engine will fit in the oven. It is a big single so it is a tall engine, beside, with all the oil residue on the engine the stink of fried oil in the kitchen would not make the wife happy. I have a 1000 degree industrial heat gun and a oxy acetylene torch so I have access to plenty of heat. Tried both and no luck so far.

 

[stangmx13]

Id probably be at the stage where I take a chisel & hammer to the piston. 1/2" from the rings is probably a good place to start chiseling.

 

[Dogfeathers]

Well actually instead of using a hammer and chisel, I was thinking of drilling about a 1/2” hole at 90 degrees off the wrist pin axis at 11 and 1 o’clock and at 5 and 7 o’clock and then using a hack saw and cutting the piston to the cylinder wall as far as I could probably having to stop when I got to the underside of the rings. Then use a drift and BFH to knock out the wedge created and hopefully the reduction in surface area would work things loose.........I hope!

 

[buellistic]

I have a dreaded “pacbell” email account (at&t related) and there is some kind of cat fight going on between BARF and them so I cannot post pictures or do a lot of other stuff on Barf. Just a rusty corroded engine, you have seen them before and this one looks just like them.
And I don’t care to open up another email account just to post a few pictures. Post one picture, get 1000 spams, ....nah.:ride

I just take a screenshot of my pic.
And it works....

I just un froze this after 10 years under water...

 

[buellistic]

Put it in a bucket and try reverse electrolysis..

 

[Dogfeathers]

Buellistic said:

I just take a screenshot of my pic.
And it works....
*********
I am not sure what to do with that information. When I click on a icon to post a picture it asks for a url. I do not have a picture posted on a image hosting service, I cannot post one I have on this computer as it has to address me thru my email address and it stops doing anything as soon as it sees “pacbell”

Just to -get- a place on this website some administrator has to do some trick to get me on BARF at all. If you know some trick, let me know.

 

[elemetal]

Adapt a harmonic balancer puller (or other handy gear puller) to the head bolts/studs and use something like a plate or block to distribute the force across the top of the piston. Apply pressure and continue to let sit in oil. Use a torch to heat until the oil starts to smoke then let cool. Apply more pressure with the puller. Repeat process. You'll get there....

The slow, continuous pressure works better than single, hammer impact. Try to apply the pressure evenly so the piston isn't side loading in the bore. You could also try to drill in one spot on the edge of the piston, into the first and second ring land. If there are two rings and the top one is sealed shut you won't get any penetrant into the land between the two or down to the second ring (maybe why it is being so stubborn).

 

[scootergmc]

porta power.