Originally Posted by ludeboom
the cams and crank are keyed and will rotate correctly without their retaining bolts installed (not at high rpm)
the belt is obviously broken or the crank timing driven gear is stripped off. rotating the engine is probably mashing any valves that are stuck open from the first stall. fact remains the belt is broken, u probably have internal head damage and either way the motor needs to come out or at least pop the lower timing cover and face the inevitable... and then remove your head and get the valves and guides changed
~boom
I totally forgot about the keys.
h: I posted really late at night and I was really tired, never will I do that again.
But yeah what you said is totally possible.
Do the b20b pistons have the cut out for the valves? If it does then you maybe in luck. If you have a hand vaccum pump with a gauge, you can use it to see if the head is leaking with the valves closed on the intake and exhaust port side.
I can't think of a Honda engine that isn't interference, maybe the older ones like from the 70's or something.