Will a 1998 civic motor fit a 1993 Honda civic?

Yes and No. The motor itself will fit as long as it is the same series of motor. Any D series motor is interchangeable. The Problem you will run into with a 98-93 swap is the computer system interchange. A 93 civic is running Obd1 and a 98 civic is Obd2. If u are changing the type of motor from say D series to B series i would refer to a forum that has a walk through to swap, or at least a list of parts you will need to buy for the swap. a good resource is Honda-tech.com

the motor itself is interchangeable, and most of the sensors... if you have old motor swap everything over so it will just bolt right in..