Engine swap for '84 318i

[Hunchybird]

I recently acquired an '84 318i for free but it doesn't have an engine. I don't want to put in another M10. I am thinking about either an M20 or an M42 from an E36. I'm not trying to build a racer, just a strong running car worth the effort to put back together.

What is involved in putting one of these engines into my stock '84 318i?

Would I have to replace the transmission? And if so, what mods would a newer tranny require to my car's drive train, mounts, electricals, etc.

The car has a 5 speed manual box now (either a Getrag 240 or a ZF S5-16, not sure, probably a ZF).

I have read that I would need the wiring harness, computer, and probably a beefier front end suspension. Other than that is it pretty much a bolt on thing?

Thanks from a rookie!

 

[E30m42cab]

Welcome aboard! I hear ya about the M10. The only way I would go about this is if you can score an E30 with the M20 in it. You're going to need a lot of parts. Drive shaft should work with the old tranny, but exhaust, computer, mounts, radiator (probably more, like fuel pump, MAF sensor, O2 sensor) will be needed. If you find a M20, the harness should still be with it. Tranny should be okay on it's own, but a 325i's clutch assembly is slightly larger. Might want to go with some disc brakes at the back as I assume it has drums.
An M42 from a E30 or M42/44 from an E36 will be the same deal. Of course it can be done, and not without a price (like the car itself), but you'd be better off finding another E30 with all the goods and just drive it. Seriously. Unless this 24 year old car shell is in magnificent shape, I don't think I'd spend the time.
On the other hand, I've spent lots of time on old 325e's to know that the learning experience can be great.
Check out all the part differences here:
http://www.realoem.com/bmw/select.do?vin=&kind=P&series=E30&arch=0
Don't mean to burst your bubble.

 

[Doughnut]

You will need to swap out the front subframe as I'm quite sure they are different, the best bet would be finding an m20 from the same year with wiring loom and ecu, and see how you go from there, or purchacing a good whole doner car for the swap.
If your quite mechanicly inclined it will be a great learning experience as Scott said, and will leave you very happy in the end.
Good luck and welcome to bmwboard!!