I currently have a 2007 mini cooper s r56 with a busted n14 engine and I don't want to see the car go. I am currently looking into putting a new engine in the car, but the n14 engines are too unreliable and expensive in my area. I have found a k20z3 engine from an old 2008 civic si with 180k km (110k miles) for $1800CAD ($1450 USD). I know enough about car repair to do the easier jobs, but I could not do perform an engine swap myself. I think it will probably cost at least $5000 for my mechanic to do this job. Do you think this is a realistic idea for a car that needs to be my daily driver?

 

Find a rebuildable N14 and spend your $5K on it --- forged rods and pistons. Or lose the car completely and get something else. If you replace the N14 with a different engine, you'll have something only you and your mechanic can work on. Not worth the challenge. And resale value will be lousy.

 

There was a guy that swapped a k24 into a R53 a while ago. https://www.northamericanmotoring.co...-into-r53.html
As for keeping it simple, I would lean towards doing what oldbrokenwind said.
What do you mean when your motor is busted? Did it burn an exhaust valve? Timing chain let go? Throw a rod? These motors aren't that bad if you take care of them. Here's a site to find a long block or even a short block if your head is still good. Car-Part.com--Used Auto Parts Market

 

I got the car from a "mechanic" who had bought it from the original owner. all I was able to get out of him was that "The head blew up" there was no head when i bought the car, and it looks like one of the pistons may have made contact with a valve, but its been so long i don't really remember. For me the value of the car was as a rolling chassis. well spec'd and in excellent condition, so the state of the engine didn't really matter to me.