e21 swaps?

[Gadea]

I don´t know of any E21-specific sites, so I´m posting this here, and knowing there´s some serious BMW heads here, I´m sure someone already explored this option. There´s this gorgeous E21 in really good shape (paint-wise, no rust, interior is really good) for sale locally and it has a bad motor (that´s why it´s for sale) and transmission is pretty much worthless without that motor. So, I´m thinking this is a perfect candidate for a swap, and the question is basically, what options are viable without going into extensive modification. I´m basically thinking M42 is an obvious choice, M20 probably too. How about M50/S50 or M30? I have no idea what fits in the E21 engine bay, or what are possible clearance issues, so if anybody does, please throw it out here or point somewhere else:hitler:. Thanks

[EN318isPDX]

M20 is the most straight forward because it came in that car stock. Id build an M20 and drop it in, or

http://motorswaps.myfreeforum.org/about3.html

[svn2002s]

If its a 4 cylinder,you can fit any M10, S14 or M20 + 323i front cross member + tranny. If its a 6cyl (323i), get an eta bottom end with 325i con rods + an 885 head or super eta head. There's a ton of possibilities it all depends on your wallet.

[bmwstephen]

id vote m20. reliable and abundant

[Teaguer]

Any engine that can fit into an e30 can also fit into an e21.
At least all the popular ones, m30, m20, s50, LS1, SBC, Ford v8, Buick v6.
Yeah pretty much all of them have been done.

M42 is a popular swap and pretty much goes right in size wise.
M20's also fit of course as 323's and 320/6's had them as original.
The m20 swap will need the 323 or 320/6 front subframe to make it a bolt in affair.

I would imagine the m/s50's would also need the 323 & 320/6 subframe to keep it sipmle and bolt in.

For more options or even build threads you should check out the bfc e21 section : http://forums.bimmerforums.com/forum...prune=30&f=143

[greg1333]

323i e-21

with the proper front cross member, and driveshaft an M20/tranny will drop into an e21. Be aware that if you use an e30 tranny does not have a speedo output. The e30 normally takes its input off the rear diff and the e21 takes it off the tranny.

Another thing to consider, powersteering units for e21 are rare as hens teeth...i only mention it because parrellel parking with a m20 under the hood is harder than with an m10 or s14.

best of luck.

[Gadea]

Another thing to consider, powersteering units for e21 are rare as hens teeth...i only mention it because parrellel parking with a m20 under the hood is harder than with an m10 or s14.

best of luck.

Greg, thanks a lot for mentioning that, I did not know. I'll see how is the steering on it this thursday. By the way, being so similar to the E30, swapping a steering rack into the E21 should be pretty straightforward, .....right?


Thanks a lot for ALL the input so far. R3V delivered again!! I always loved E21s. The euros look even better. Like, a lot better. The difference (between euro and US models) is much less accentuated in the E30 IMO.

[Gadea]

I'm inclined towards the M20 or M30. Cheaper in comparison, plenty of power for such a nimble car (I had an euro 316 and it had enough), and abundant enough.

[LJ851]

E21 rear steer, E30 front steer so no easy swap unless you dont mind steering left and turning right !

[Gadea]

I don't mind it at all, I drive forklifts all day at work. But seriously, I hope you're being sarcastic or something, or I don't know what you're talking about.

[LJ851]

im serious about what would happen if you put an E30 rack in an E21. The steering arms come off the rear of the strut housings on E21 so the rack pushes to the right to make the wheels go left. E30 has steering arms on the front of strut housings so its rack pushes to the left to turn left. If you swap racks your steering will be reversed, make sense?

[Gadea]

ah, Ok, I see....
didn't know that :P

[Gadea]

what about swapping the whole thing? struts, spindles and everything. Well I guess I have other things to worry about and stop messing with this idea altogether and keep the original steering

[LJ851]

you dont need to sweat it though, the steering will be fine with whatever engine you put in. BMW thought it was ok with manual steering and an M20, and ALPINA thought it was ok with an M30 ! You cant steer with one finger in a parking lot but thankfully most of us driving out there also have arms and they work great for the low speed turns. I have a couple 323 5speed gearboxes if you decide to go the M20 route, i might be persuaded to sell one.

[Eecen]

http://www.bmwe21.net/forum/
-bimmerforms e21 section.

Lots of good information on those sites.
Do a lot of reading before jumping into the car.



Unless you can get a 323 front subframe you will be making engine arms for any swap you do. M30 you'll have to make mounts or buy them no matter what.

The differential is small. Can't take more than 200hp, depending on its ratio (according to Metric Mechanic).

Rear drum brakes, unless the car is a 323.

etc etc