[Mart]

No timing chain, just gears.

I had a french motor that was lightly seized on one cylinder. I pulled both heads and the oil pan. I was able to identify which cylinder was sticking by moving the crank back and forth and feeling for movement on the pistons. I loosened the big end on the rod on the stuck piston and was able to rotate the crank away from it, just a bit. I was then able to knock the piston down because it now had somewhere to go, and was able to move on it's own.
I kept moving the crank away and knocking the piston and rod down to meet it. With plenty of lube applied I was then able to rotate it and push that piston up.

What I'm saying is that you have a better chance of moving a piston if it can be moved in isolation rather than trying to move the crank and all the other pistons at the same time.

It isn't actually easy to take out the crank if you can't rotate it. Some of the nuts are hard to get to.

Mart.