I bought a used d16y8 off of fb marketplace about 2 weeks ago. When I got the engine I made sure the engine rotated when I would turn the crank by hand. Everything else looked good too. Mounted up the transmission and then tried turning the crank again and it wouldn’t turn at all no matter how much pressure I would put on it. The crank pulley bolt even busted loose. So I put it in the car thinking maybe it has something to do with the autonomic transmission. When I would try to start it , it wouldn’t crank or anything. Sounded like a starter. Bought a new starter and still no crank or anything at all. Switched out transmission’s again . And the same thing the engine won’t rotate when I try to turn it by hand. But put it in the car and now it cranks and cranks but won’t start. I’m lost of why I can’t turn the engine by hand. I wanna make sure the timing is right but I can’t turn the engine. It has spark and fuel. It’s in a 2000 civic ex. Any idea’s? I would truly appreciate it. Thank you I’m advance.