Stuck piston and neck bearing question

Thank you all for your help, got the engine unstuck using compressed air as suggested. Had to put the head back on but didn't bother with the push rods then put more Marvel Mystery oil in and using a modified sparkplug put air to it. When she hit 80 psi that did the trick. Now I can inspect the bore and the rest of the parts.
Again, thanks.

N0rt0nelectr@ said:

Thank you all for your help, got the engine unstuck using compressed air as suggested. Had to put the head back on but didn't bother with the push rods then put more Marvel Mystery oil in and using a modified sparkplug put air to it. When she hit 80 psi that did the trick. Now I can inspect the bore and the rest of the parts.
Again, thanks.

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Thats great to hear.
Good luck on your rebuild.
Cheers,
Thomas
CNN

N0rt0nelectr@ said:

Thank you all for your help, got the engine unstuck using compressed air as suggested. Had to put the head back on but didn't bother with the push rods then put more Marvel Mystery oil in and using a modified sparkplug put air to it. When she hit 80 psi that did the trick. Now I can inspect the bore and the rest of the parts.
Again, thanks.

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If it came loose with only 80PSI on it I doubt you'll find too much damage. I got an airplane piston loose with over 500 PSI of nitrogen on it and it cleaned up with just a glaze breaker. Put new rings and it was good to go. Borescope on the other cylinders looked good after we ran it.

We had to get the piston loose by pressure as the head and barrel are all one piece so there's no way to smack it with a block of wood.

I just read my posting and it's not clear. The engine in question had been in storage and wasn't mounted. It had desiccant plugs in all the cylinders but one, that one had the top one missing. The others had changed color but not quite to fail. Lacking a propeller we tried to turn the crank but it wouldn't budge, hence the effort to get the suspect piston free.

Anyway, it all worked, we mounted it and it flew away.

N0rt0nelectr@ said:

Thank you all for your thoughts and insight as to how I will remove this stuck piston. I do plan on striping in all the way down and inspecting each and every part before putting it back together.
The head is off of it and I was able to remove the other spank plug. I think that was a good thing in that at least that side doesn't have a stuck piston. My wife wasn't happy that I had the head in the oven to heat it and help me get the plug out. I might just put the head back on and try the air and penetrating oil route. All that will cost me is time and I have lots of that.
Again, thanks

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I put the head back on less the push rods. Put more Mm oil in. Built an adapter for the spark plug hole and added air, at about 120 psi there was a bang and the stuck piston was free. I have stripped the engine, cleaned out the crank, polished the rods installed new rod bearings, new super blend main bearings and away we go!
Thank everyone for their input.

The cylinder is the important part to salvage as it can be re bored once the piston is removed

try applying heat and bath in hot oil , if the piston will not let go do not force it , i have seen pistons driven out with blocks of wood and cylinder bottoms pulled clean off as a result

drill a row of holes around the crown and break it up good chance it will be the rings rusted to the bore once you break them loose the skirt will normally let go with some heat and lube and gentle persuasion

Go easy and sacrifice the pistons as New pistons and a rebore will be required and cost less than new cylinders