Can you put any engine in any car?

I have heard of people putting like a Nissan engine in Ford car. Can you do that with basically any car and engine?

In theory, sure… But there are enormous practical problems with doing significant engine swaps in modern cars. Engines used to be something you could lift from one car, find a way to bolt into another and get the exhaust and drive train to mate, and there you go. In the early '70s my brother replaced the 4 cylinder engine in a Vega with a 454 V8.

Today it is vastly more complicated. The old engines just had ignition wiring to worry about and that mostly was mounted to the block. Today the engine has lots of tentacles snaking through the car. The first is the ECU, which is as much a part of the engine operation as the crankshaft is. The engine wiring harness and the ECU wiring harness (often two separate pieces) are part of the deal. Lots of people want to replace a 4 cylinder with a 6 cylinder, or a 6 with an 8, not even thinking about the harness not having injector connectors for the extra cylinders or the ECU having no idea how to deal with two more cylinders. There are many similar complications - if you put an engine with electronically controlled valve timing in a car that never had it the valve timing will stay in mild mode unless the ECU and harnesses are right.

So the answer is yes, and brand is the least of it. The major complication when changing to an engine that was never offered in that car is custom making or modifying a harness that will connect the foreign hardware in the car.

As for the legalities, in California the answer is flatly "no." I don't know which other states follow California standards.

As long as it physically fits, sure.

But it would not be just the engine alone that would need to be swapped. Basically you would need all the wiring and control units for the new engine to be swapped as well at the same time. Then you have the issue of getting the power to the wheels. The original transmission won't work with the new engine so the transmission would need to be swapped as well.

While it can be done, it is not an easy task to do. Major modifications would need to be done throughout the whole process which would add a lot of time and probably money to the whole project.

For the most part yes. However, putting an engine designed for front wheel drive into a rear wheel driven car would be expensive, difficult, and just plain stupid.

Also, in areas where emissions checks are strict, the installed engine must be able to pass inspection and meet that year emissions test.

You can put in other parts to each-other but not the entire engine…

If you can fit an Allison V12 into a BMW Isetta, well anything else is cake.

There are some differences such like front and rear wheel drives, but in theory if you can fit it in you can make it work

Sure you can… If you have enough money.

If you disregard any sort of cost / benefit ratio yes. All it takes is cubic dollars.

Yes. But you are not using correct grammar. "Could any engine fit any car?" is correct. The use of "you" is not appropriate.