rotating the crankshaft would still do the same thing as starting the car. it would could fuck shit up. you have two options one put another timing belt on and then do a compression test or two take the head off and take a look. if your going to rotate the crankshaft the pistons will go up and down and the valves are going to be stationary. you have a interference motor you cant just go cranking your motor when your valves are not moving they will interfere.