Zero compression - seized piston rings?

[DocForker]

In my 68 75hp Chrysler even though everything is turning over nice and smooth with the new head gasket I have compression of 0-60-30. There is no damage or groove in piston or head. I took Reed valves off and everything looks ok (but crank is rusty) on the intake side. This engine sat outside without sparkplugs for at least a year with prior owner. I'm thinking the rings must be rusted in place. Does that sound plausible? Can I use a propane torch on the piston head and maybe loosen them up?

I shot this video: https://youtu.be/_6JfK8JgOVI

 

[DocForker]

No Title

Photos of the piston head and cylinder walls. Walls smooth to the fingernail. When I first opened head they were rusty. I cleaned them from the rust.

 

[gm280]

I don't think a stuck ring is your only problem. I think you need to totally rebuild the engine if you plan on keeping it. Circular movement with the piston points to either wrist pin problem or connecting rod issues in the bearing areas. The only plus I can see (not being there) is that you can have the engine re-bored with new pistons and rings and bring it back to factory specs. But I would certainly look at the rods and bearings and hopefully the crank is good. But that is merely a wild guess not being there and testing things myself. JMHO

 

[Scott Danforth]

If the crank is rusty, the bearings are rusty. Time for a complete teardown and rebuild

 

[ondarvr]

And on that motor I wouldn't recommend a rebuild, just get a different motor.

 

[tpenfield]

And on that motor I wouldn't recommend a rebuild, just get a different motor.

​+1 ^^^ might not be able to get all the right parts for a rebuild.

 

[kbh121956]

If the crank wasn't rusty I would have just tried new rings with a hone job. Do you have inside mics too check for cylinder wear? If the crank is rusty chances are the bearings are also as Scott Danforth stated. Once the bearing are rusty they have been compromised.

 

[jerryjerry05]

Did you just change the head gasket with one that was somewhat different?
​That's probably the problem.

Still have the old?
Place it over the new and see if the inner rings align?????