this is a stupid question but i just want to make sure everything is ok. i put both my heads on today and headers, spark plugs are in and no rockers are installed yet. i can crank over the engine by hand but slowly obviously because of compression. should it turn over at all if valves are closed and spark plugs in though. you can hear a hissing noise from air escaping as you try and turn over.

 

normal, you do get some compressin loss past the rings