Hey, I’m Nelson. Just bought myself a 1991 s13 240sx, DOHC. But i was thinking of getting a rb24 or sr20, but i dont know what i would need to change in the engine in order for one of these engines to fit in there. And which do you think is best to put into the car? :/:
If your hot to trot, SR is direct and an easy swap; to do yourself if you are handy,
If you want to drop $6000++ sure you can pay certain people on this board to do either…
Google search it,
However, might I suggest that suspension, tires/wheels, brakes are a better start as the stock KA makes adequate power.
Take a year to familiarize yourself with the way the car handles etc. before doubling the horsepower
stock turbo RB’s come in RB20, RB25 and RB26 (displacement in litres)
Well put, I have had my 95 s14 for almost two years, and first thing I did was brakes and suspension, the Ka does have some decent balls, I am just now turboing it! Just like s13 said take your time to get used to the car…
Ya i was planning on driving with my KA for a good year since it only has 180 K’s original. I’m only going to start buyin parts after a good year.
then i guess you have a year to do your homework 
your question’s pretty generic and based off of “rb24”, i’m assuming you’re fairly new to 240’s?
i would recommend checking out some of the threads on nico club, ka-t, and even check out wiki for some history on the cars and what kind of parts are transferrable between cars.
but as someone said earlier, don’t worry about swapping out your ka this soon, read up on the footwork first: tires, wheels, brakes, suspension. chances are a lot of your bushings are shot so if you want to have a nice platform for your future swap, start addressing these things first to give you a nice ride when you up the power. hope this helps man, but remember, it’s still your choice of course…just try to google some things ahead of time to get the basic knowledge of things down (or it might be hard to get the advice you’re looking for here)
thanks for the advice, guess the best thing to do first is learn all about the car.