I drive a 2015 Civic EX Coupe and I wanna swap the engine to something more powerful (have a 1.8L SOHC). Been doing some digging on my own but haven’t found anything that would fit my car. Any suggestions?

 

I would suspect the K20Z3 motor would bolt in without issue. It's the Si of that generation (chassis).

 

Do they make a single overhead cam of that? My engine bay is really small and I’m not sure a double would fit

 

Yes, get a complete drop out from a 2012-15 Civic Si (including knuckles, brakes, cradle, radiator, axles, shift cables/shifter, engine, ECU and tranny, etc.) and that will be a great start.

That is actually the previous generation DOHC engine... what the OP needs is the K24Z7 from the 9th Gen Civic Si.