24V AWD Swap Knowledge Base

[Nisse Järnet]

Nice work :)

[The Dark Side of Will]

Thanks!
I thought I'd be able to put something simple together from a few easy to cut pieces... no such luck. Thanks, BMW.

[The Dark Side of Will]

I've been thinking about engine mount arms for a while. Of course I've been on this project for a while too, but who's counting?

The crossmember I've showed heretofore is a fit-check prototype. It's designed to support the M20 in the stock location to check for rack clearance to the sumps of 24V pans bolted up to the M20. As such, I've suspected that the engine mount locations are going to have to change for the operational (dare I say "production"?) version.

The iX uses mount points that are several inches further forward from the bellhousing mounting surface than the "conventional" RWD mounts for most RWD BMW's of the era.

The RWD E34 is the only body in which the M6x V8 and the M5x I6 use the same subframe mount points for the engine. However, those are conventional mounts so the arms wouldn't work... or I'd have to develop an elaborate structure to reach back to support them.

The AWD E34 arms actually go *BACK* from the conventional location instead of forward.

The E53 has a weird setup in which the right arm goes forward and the left arm goes back... so maybe I could use the right arm for both I6 and V8 but fab something up for the left for both apps.

I ultimately realized that I'll just have to re-use the M20 iX mount arms, but rotate the mounting surfaces around the crank centerline (lower the right mount and raise the left mount) to put the 24V engine at the right angle. After all, every iX to be swapped will have the M20 iX mount arms, so it makes a 24V swap that much simpler. I'm probably the only weirdo who will do the V8 swap, so I'll just fab the V8 mount arms (or maybe I actually can re-use the E53 right arm so I only have to fab a left?)

I'll do away with BMW's mount towers, as those actually complicate the crossmember design by requiring *THREE* mount locations per side instead of one. The plate the mount bolts to will then be 1/4" steel instead of the 3mm or so that BMW made their mount towers from, so it'll be able to handle powerplants like Nisse's with ease ;-)

[nando]

My plan honestly is to weld brackets right to the frame. For the N5x series engines, theres nothing obvious that works for the ix mount locations (and I have like 4 different sets). Then i can use the leftover space to adapt the E46 ix rack, which the E30 needs desperately...

[The Dark Side of Will]

Well maybe we can figure something out. S/M5x swaps are easy, but BMW isn't building any more M5x engines and the N-series engines are the future.

[AWDBOB]

Does anyone need a spare iX oil pickup tube for modification? I have one on a motor that's going bye bye. PM me.

[nando]

I got the pickup tube, thanks!

Lately, I've been staring at the engine that's been in my garage for the last 4 years, and really considering doing the initial swap without AWD. The RWD 24v pans clear the ix subframe easily without any modification required - and I could have this swap complete with only having to finish the engine, and not a rebuild of the whole AWD system.



I'm curious how it actually drives without the front wheels being powered. I've heard both good and bad but it's not done often. Also I would only do it until such time that I can finally get a AWD pan fabricated and rebuild my front CV shafts (which are in sad, sad shape).

[notanawdix80]

I got the pickup tube, thanks!

Lately, I've been staring at the engine that's been in my garage for the last 4 years, and really considering doing the initial swap without AWD. The RWD 24v pans clear the ix subframe easily without any modification required - and I could have this swap complete with only having to finish the engine, and not a rebuild of the whole AWD system.



I'm curious how it actually drives without the front wheels being powered. I've heard both good and bad but it's not done often. Also I would only do it until such time that I can finally get a AWD pan fabricated and rebuild my front CV shafts (which are in sad, sad shape).

I drive my ix without the front power.

It's not horrible. I've never been to a track though.

I'm ready replacing worn out stuff from the suspension so probably i'm gonna test it on the track some day and i will tell you haha

[The Dark Side of Will]

Finally have the .igs file with the engine mount tower CMM data. I imported into OnShape and did some work. A MUCH cleaner design results.

[Eskie]

If you need any help with measurements or pictures from components from X-drive vehicles let me know. I work in parts at a BMW dealer and have 2 E30 iX's myself. One of which I'd love to swap a 24v into.

[The Dark Side of Will]

Thanks! I may have to take you up on that.

I had a realization...
The engine mount pads are tilted toward each other by 20 degrees from horizontal. The M20 is tilted over at 20 degrees. Thus the angle from the engine block mating surface to the engine mount mating surface on the left mount arm should be right at 90 degrees.

That makes it easy to spot check angles on the RWD left mount arm vs. FWD left mount arm. I guess I know enough to order some mount arms now...

[The Dark Side of Will]

I found an eBay seller with both sides of both RWD and AWD mount arms for sale, so I grabbed all four.

Because of the right angle characteristic I noted above, it'll be SUPER easy to get the lateral and vertical relationship between the RWD and AWD mount locations from that one arm. It'll take a smidge more thought to get the longitudinal relationship, but I think that's readily doable as well.

Also, does anyone know how much the M20 powertrain is tilted front to back?

[Eskie]

I found an eBay seller with both sides of both RWD and AWD mount arms for sale, so I grabbed all four.

Because of the right angle characteristic I noted above, it'll be SUPER easy to get the lateral and vertical relationship between the RWD and AWD mount locations from that one arm. It'll take a smidge more thought to get the longitudinal relationship, but I think that's readily doable as well.

Also, does anyone know how much the M20 powertrain is tilted front to back?

I can measure both of mine. I don't have an angle finder--I could always grab one from harbor freight or amazon. Would there be a way to measure it otherwise?

[Eskie]

Actually..my phone has one built in. Should I measure with the car on a flat surface across the valve cover?

[nando]

it's 15 degrees. that is well known. all 24v engines are 20 degrees.