I have tried to search for the answer in the threads. But I didn't get the answer I was looking for. I have an 88 N/A Vert. I wanna put a TII engine in it. I was wondering what is the difference in putting in a S5II engine than putting in an S4. I can't think of any , but I am also new to rotories.

 

Its not plug and play if that's what you are thinking. The engine harnesses are different. You can make it work but how much time and money do you have to invest. Search a little harder cause there is a lot of info available. I dropped an 88 TII swap into my S5 and bought more than half the stuff needed before I said the hell with it. I just pulled the motor and sold my S5 shell last weekend. Luckly I was able to find a running n/a S4 that I'm using as a donor.

 

Try searching harder, been covered many times before.

Pretty much, putting an s5 engine in an s4 is pain, especially if you're new to the rotary world.
Spark timing is different, OMP is electrical, not mechanical, ECU plugs are different.... etc.
I think you'll be much better off sticking with an s4 TII engine. Of course there are those who will say go for it. This is but one man's opinion.