for all questions pertaining to baseless, general and vaguely worded questions please use the SEARCH button. I doubt youll get much with "fast 4 door 91 civic" but type this in...

B18C1 swap
H22 swap
B16a swap

thats just a few, or integra type r motor swap, civic type r motor swap, prelude motor swap, integra gsr swap, honda civic si swap

you wont learn if you dont make an attempt.

and please word questions better and of course your budget (cant swap a motor in for free, always an expense)