I picked up an '81 320i for a parts car (it also runs, I drove it all winter last year) for $400, and I'm wondering what exactly is required to swap the motor over. Do I keep the EFI from the 320? Or do I keep the carbed setup from the 02? And is there anything else I can swap over to the 02 besides the motor? I've never worked on an older motor before, so I'm somewhat of a newbie. Thanks in advance.

It's a pretty easy swap. Nice and reliable. Great mileage and good performance. I have a Metric Mechanic 2.2l with the 80-83 e21 cis injection set up.

You can keep it carb'd. We actually just put an e21 motor in an 02 we just sold. The only thing you have to do if carbing, is get an electric fuel pump, and block off the injector holes. Its not that hard to do.

Edit: if the e21 has a 5 speed, you can use that too, most likely.

Thanks for the quick replies. Wow that is a clean engine bay fjord. Good to know its nice and straight forward. Although I actually sort of like the 4 speed (more the amusement of driving a 4 speed vs a regular 5 speed), I plan on swapping over the 5 speed too. Is it more beneficial to run it carbed or EFI?

EFI is almost always better for mileage and driveability, cold weather/altitude, etc. Running it on a carb wouldn't require any real changes, meaning a simple swap. EFI would require a lot more work, but certainly be worth it more the longer you keep the car.

If you strip the 320- I would be interested in the LSD rear end.

what exactly is required to convert to EFI? And is there anything else I can take off the car (suspension, brakes)? I'm not sure if it does have a LSD, but I can verify and get back to you. I didn't think it did, but I'm not 100% sure.

Carbed vs. CIS vs. EFI.

CIS is a step up from carbs (in terms of altitude/cold weather/economy-wise running) and EFI is another step up from there.

All the USA 320i and 320is models came with CIS. Adapting to that if you have a donor car would be difficult, but not bad. For the work involved, EFI woudl be better.

EFI requires a few pieces to be fabbed and/or pieces from the E30 318 M10 engine. People have done it with the factory E30 injection, Megasquirt, SDS, etc etc.

A controller (ECU), intake manifold, fuel injectors, rail, supply pump, hoses, sensors, and some wiring. Sounds simple.

Most 80-83 320i models were actually sport models with Recaros, 5 spds, and LSDs. Just jack up the rear end and spin a tire - if the other goes the same way, its an LSD.

Thanks.

ok, I'll probably end up keeping it carbed for now.
Does anyone know if any of the suspension components are interchangable? I drove the 320 this past winter and replaced the tie rod ends and a couple of other minor things and I'm wondering if I can just swap them over if they are the same. I'd rather not waste those parts since I'm going to try to take as much as I can off the 320. Anyone know what else I can take off the car?

If you strip the 320- I would be interested in the LSD rear end.
the run of the mill 320i doesn't have an LSD, only 320iS's and 320i's that had it added as an option.
Jake