1991 Dodge Spirit, 2.5L, NON-turbo, automatic transmision

I have a broken timing belt. I verified that by checking that I have no
rotation of the distibutor rotor while cranking the engine. Before I start
replacing the belt, I would like to find out whether the engine is damaged
otherwise. Is there destructive interference between the valves and pistons
when the camshaft does not turn? Thanks for the help.