318 or 325 for M30 Swap

[QBANG]

Well I have found a 91 318 with a bad motor that I can pick up for a few $100 bucks. The body on the is in really good shape, the paint is fadeing but other then that it looks good. No rust from what I can see.

Here is the deal, I have a 87 325 sitting in the driveway but the car has some issue, a little rust and lots of dents. Is it any more work to swap into a 318?

[E30SPDFRK]

Easier in the 318, but just barely. The 325 you will have to change the c101 plug on the m30 harness whereas it will plug right into the 318. Really the same in the end so just go for whichever one you like more.

[Jean]

Pick the cleanest body/paint, rest are small changes.

[Jonsku]

But now you're forgetting all the important issues like brakes and suspension!

You need to swap at least E30 325 brakes and suspension bits to that 318, preferably recondition them at the same time.

[Danny]

But now you're forgetting all the important issues like brakes and suspension!

You need to swap at least E30 325 brakes and suspension bits to that 318, preferably recondition them at the same time.

Its the same stuff.

[msinger]

Its the same stuff.

Last I heard the 318's and the 325's did not share the same suspension. different springs and struts at least, despite the brakes being the same.

[Brian D]

It's a 1991 318, suspension and brakes are the same. Early('84-'85) 318's have smaller strut tubes.

[QBANG]

Brian D,
What about the rear end? Are 318's small case 4.25's?

[wildstoats]

Brian D,
What about the rear end? Are 318's small case 4.25's?

318's are small case but the axles are the same as the medium case cars. Just get a medium case diff with the e30 back plate and you're in business. That's what I did on my m30 swapped 318. You're going to want a different diff anyway unless you have a vendetta against tires. :p

[Brian D]

Brian D,
What about the rear end? Are 318's small case 4.25's?

As mentioned, small case, which you'll want to swap. My buddy's 91 has a 4.10.

[E30SPDFRK]

The small case is still plenty strong for the m30. Mine has been humming since I bought the car. I beat the hell out of it trying to break it so I'd have an excuse to replace it but it's still holding up fine. I'm hoping the new engine will finally be it's death lol.

[Jonsku]

Its the same stuff.

Last I heard the 318's and the 325's did not share the same suspension. different springs and struts at least, despite the brakes being the same.

It's a 1991 318, suspension and brakes are the same. Early('84-'85) 318's have smaller strut tubes.

Ummm.. are there again special-models in USA? 318iS (with M42 engine) does have the big stuff, but not the 318i (with M40 engine). At least that's the thing here in Europe.

Anyways, you can check which parts are on which car at www.bmwfans.info or www.realoem.com

[Danny]

Ummm.. are there again special-models in USA? 318iS (with M42 engine) does have the big stuff, but not the 318i (with M40 engine). At least that's the thing here in Europe.

Anyways, you can check which parts are on which car at www.bmwfans.info or www.realoem.com

The US only got the 91 318is. There was no m40 imported over here.

[Brian D]

edit-faulty memory.

[QBANG]

Well I picked up a 1991 318is this past weekend. Is there anyone that has done a M30b34 into late 318, is there anything to watch out for? Im scared of the wireing :)