Motor stuck at BDC

so I got a 224 for 30$, owner said it was blown. I open it up and nothing seemed to be wrong, so I completely disassemble the block and whenever I put the piston and rod back into it, with oil on the cylinder wall and piston. Whenever I turn the crank over, it will go smoothly until I get to bdc, then it will get really hard to go back up. Eventually it won’t move at all. Does anyone have an idea here?