there are LOADS of things different on the 1.8/2l than he 1.4/1.6.

intake and exhausts are on different sides for a start. sensors and management are different so will need engine loom and ecu, then you'll have to sort the immobiliser out and possibly keys.

not worth it unless the car is a good base and you want to drop a big bhp motor in.

incidentally any 1.6 zetec se will do, early or late gen (aluminium cam cover and plastic), they'll swap no problem.