Project 320ish - 1979 M50B25NV E21

[Somjuan]

The last thread got jumbled and hard to read even by my standards, so I figured I'd start fresh!

The end goal of this project is to have a fully functioning M50NV in the front of my car that still leaves the car comfortable and properly handles. Oh, and it has to pass California BAR standards. Turns out that a lot of things have to change to make that happen safely, up to and including a complete redesign of the drivetrain and a whole bunch of Frankenstein-ed parts being thrown together. The last few weeks I've been calling in favors, horse-trading parts, perusing Craigslist ads, and hitting up sales to collect pieces. It's all been a wonderful learning experience.

Here's a quick overview of what's on the table as of the moment:

• Suspension System
• Engine Refresh
• Drivetrain Changes
• Braking System
• Exhaust fabrication
• Rebuilding and fabrication of all of the above

Coming in at dead last is bodywork, which at this point is not great but passable. So, uh, basically the whole car needs to change...at least the front suspension gets to stay?

So let's start with the motor!

The big 24 valve lump going up front weighs in at 500 or so pounds after shaving off the parts that the e21 doesn't need, like that pesky power steering system. I sourced one locally that had two flaws. It was an automatic, and it was an e36. For those of us that haven't read up on this swap, one of the most necessary parts of the swap is an e34 oil pan, which doesn't come cheaply off the car unless you pull it yourself from a donor. So after waiting patiently (ish) for an e34 with a front facing sump to pop up in the yard, I got lucky.








2 by John Cahalan, on Flickr




With all of that out of the car, I got really lucky and found out that the car had been junked for a reason. On removing the transmission drain bolt, large chunks of gear the size of my thumbnail rained out. So bullet dodged there. Since it was already out, removal of the drain pan was easy and required no sawzall. Cleaned it up a bit and here we are! I also grabbed the necessary bits left from the engine, the drainpan pickup and the dipstick tube


4 by John Cahalan, on Flickr


Really that's been most of the project so far. I've been having a lot of fun with compatibility of various parts from the seventies up through the mid 2000s. Through trading around and junkyards I've scrounged up most of the pieces from a combination of cars. Here's a quick parts listing and a photo of how it's all sitting for mockup in my garage.


7 by John Cahalan, on Flickr

Engine Assembly

• 1992 E36 M50B25 with good compression and all the accessories
• 1994 E34 M50 Drainpan and pickup

Driveline/Suspension Assembly

• 1986 E28 rear subframe
• 1994 E32 740i Semi-trailing arms with slide bearings
• 1985 E28 halfshafts
• 1985 E28 3.25 LSD
• E12/E23 front non-ABS hubs
• E34 rear Bilstein damper and spring setup with e21 tophats

Braking Assembly

• E21 Brake booster
• E12 Master Cylinder
• Proportioning valve (still looking for a recommendation on a good one here)
• E36M3 front calipers (315mm rotor)
• E32 rear calipers (300mm rotor)

Miscellaneous

• 1990 VW VDO gauges (Voltage, Oil temp, Oil Pressure)

And that's how it sits right now. Still figuring out the front suspension will go, but the fully laden m20 and the m50 are actually within a few pounds of each other. With any luck I'll be able to find something compatible with the early strut tubes, but I haven't gotten there yet. I'm also at a loss as to where to put the VDO gauges. All three are just barely too big for the ashtray location on the air conditioning console, and I don't want to block the air vent at the front with the Zender setup.

Opinions and suggestions are welcome!

[Retoropak]

Oh its going to be a great build.

Swap that heavy iron block with aluminum one from a TU motor (z3? I believe) and stroke it to 3.0 with m54b30 rotating assembly.

That is actually one of my dream setups.


here is the swap i started.


Here is the gauge idea. I used standard 52mm autometers.




And the afr instead of the stock coolant temp.


There is my thread somewhere with working pictures.

Let me know if you need any additional pictures or measurements.


Proportioning valve. Use tilton or wilwood both are nice units.

Actually i want to drop the booster and go with dual master setup with the balancing bar between masters to set the bias.



Sent from my iPhone using Tapatalk

[Somjuan]

Wow! The amount of parts that interchange never ceases to amaze me. I think I can get away with swapping the lower end to an aluminum block, but the rotating assembly would be pushing it in terms of being able to smog it legally. It'd probably pass. Probably. That Wilwood setup looks nice to me for the proportioning valve.

Shame I can't put the dials there, because that looks like the perfect spot. Air conditioning is very necessary in this part of the Central Valley. It hits 112 in the summer regularly.

[hotdish]

Shame I can't put the dials there, because that looks like the perfect spot. Air conditioning is very necessary in this part of the Central Valley. It hits 112 in the summer regularly.

Do the 80s-style top of the dash triple pod. The e21 dash shape is practically set up for it.

[m60b30530i]

http://www.iemotorsport.com/bmw/item/wwvalve.html

I am running this valve in my e21.

[Somjuan]

Just a small update with some more parts, a quick engineering lesson, and a proof of concept courtesy of a friend. A 2001 Z3 3.0 Roadster popped up in one of the yards. For those of us that don't keep up with the newer bimmers, it runs off of the m54 platform, which is an aluminum block six cylinder engine with roughly the same bottom end as an m50. This one was paired with a ZF 5-speed transmission, and something special - a medium case 3.07 torsen differential.



So what is a torsen differential?

A TORque SENsing differential operates similarly to a limited slip differential in that it allows lock to occur when one wheel travels much faster than the other or when enough torque is applied to the pinion shaft. It does this by taking advantage of different sets of gears, worms and spurs, and allowing the rear to act as one solid axle when needed. A much better explanation can be found here : https://www.youtube.com/watch?v=JEiS...ctZopJ&index=1

In a nutshell if you can't watch it, a worm wheel cannot turn a worm gear, but a worm gear can turn a worm wheel. It really helps to have visual reference though. Through text I don't have any good way of explaining it further, but what you should take from this is that unless you have wheel lift, the assembly acts exactly as an LSD does, but smoother, and with more heat generated. It also doesn't wear as quickly as a clutch does. Here's a crappy photo of me confirming the internals that vaguely shows what I'm talking about.



So why this one? Well, it's a medium case. Adding to that, in order to properly hang the differential with the spare tire well underneath our car one needs the rear cover off of this car. As it turns out, the output shaft flanges are interchangeable between just about any BMW medium case differential. So while I just got the 3.25 LSD, that one needed a rebuild and this one is in pristine shape. One franken-diff later, and we have all the fun of a limited slip with less maintenance and quicker, quieter operation. On top of all of that, this car also came with a ZF transmission, Z3 shifter, and a driveshaft that should lend itself to modification fairly well to hold it all together.



So with all that said, will it fit? Absolutely.

As I said before, there was also a matter of proof of concept. In going with the E32 rear trailing arms, the offset of the wheels is brought in from et46 to et38 or so. I've already confirmed that the e28 halfshafts fit together with the drive flanges on the e32. The big difference between the two is the number of teeth on the wheels for the ABS system. Happily, that won't be a problem. Here's the photo from the thread my friend sent me that confirms the dimensions are similar enough to work together. If this were an e28 it'd be a different story. As near as I can tell from a few hours of searching, no one has tried this combo in an e21 yet. Hopefully I'll be successful. Cheers!

[tlapham]

Wow, great to see new ideas thrown out here. good luck, looking forward to seeing the results!

[Retoropak]

Excelent find.

Abs? Hmmm you can use these tone rings with ms3 for the traction control
Not sure but you should be able to set the potentiometer to adjust how aggressive the traction control is. I would call it drift adjustment knob.


Did you take the aluminum block?


Sent from my iPhone using Tapatalk

[Somjuan]

Hah! I wish I could use MS3, but again, California. The block was super dead, but it's always nice to see why a car is in the yard. The head got pulled and then it became evident that coolant sat in the cylinders for a loooong time. That and presumably the overheating that caused it dissuaded me from grabbing the short block. Down the line it'd be a nice upgrade though.

[amarino]

Hah! I wish I could use MS3, but again, California. The block was super dead, but it's always nice to see why a car is in the yard. The head got pulled and then it became evident that coolant sat in the cylinders for a loooong time. That and presumably the overheating that caused it dissuaded me from grabbing the short block. Down the line it'd be a nice upgrade though.

The M50 you are using is non-OBD, right? Just hide the MS3 controller inside a stock ECU box to pass the visual

[Somjuan]

Today was a lot of cleaning, followed by some mild success

by

Everything bolts up! Sadly the brakes on the right hand side trailing arm I picked up yesterday were the smaller non-vented variety, presumably because someone cheaped out on the proper replacement at some point. So I still need the rear right brake. The flanges between the E28 LSD and the Z3 LSD do, in fact, mate up perfectly. And to top it off, the half shafts from the e28 are the proper distance from the differential.

Now I get to clean and rebuild everything. Yay?

[320iAman]

Looks like you got hands full in mods. Interesting build

Randy

[Somjuan]

Thanks!

So again with the small victories and ideas moving forward, but finally got the motor on the stand and pulled/labelled the harness to start modifying it to be a manual harness. In terms of rewrapping the harness, what do people normally use that looks fairly OEM? Open to ideas.



I only got so far as removing the power steering components, harness, and valve cover last night before I had to stop to clean up the mess of coolant I made. Sorry about the photo quality, something's going on with my phone that's been making it worse and worse. Confirmed from the VIN on the back of the block that the block has been an automatic block all of its life. Time to change that!

Keeping with my theme of vehicular ADHD I picked up a spare cluster from a parts car while I was looking for a spare fusebox connector. Sadly there were no e21s locally that still had a fusebox, let alone a connector in decent shape. If I have to use mine I will, but I'd prefer to have the wiring more or less squared away before I drop it in the car. While I was dismantling it and staring at my still half finished dash I came up with this idea for the auxiliary gauges.

17



I'm not a huge fan of the zender pod, because while it has excellent placement for visual use it blocks air vents and almost never looks like it was meant to be there in my opinion. So I'll 3D print this and fumble around a bit until I can get it to line up well with the dash, look like it belongs, and then fiberglass the lot of it to make a single cohesive piece. Who needs the seatbelt warning light anyhow?

[cgifool]

I use "Tesa Wire Loom Harness Tape", easy to find on amazon and elsewhere..

[Somjuan]

I use "Tesa Wire Loom Harness Tape", easy to find on amazon and elsewhere..

Yes! That looks perfect. I wanted to make it look as OEM as possible.

[amarino]

Keeping with my theme of vehicular ADHD I picked up a spare cluster from a parts car while I was looking for a spare fusebox connector. Sadly there were no e21s locally that still had a fusebox, let alone a connector in decent shape. If I have to use mine I will, but I'd prefer to have the wiring more or less squared away before I drop it in the car.

Hello from the FB group There is that one E21 in south SJ and 2 in Newark. Both in Newark also still had their clusters (and wiring probably) yesterday when I stopped by. Also was 50% sale this past weekend.

Still looking for those connectors? Let me know and I can try to stop by the south SJ location one morning and cut off as much wire for the fusebox and connector. I'll send it to you at cost of the part + shipping. Not looking to make a buck.

IMG_20180401_114902.jpg

[Somjuan]

Hello from the FB group There is that one E21 in south SJ and 2 in Newark. Both in Newark also still had their clusters (and wiring probably) yesterday when I stopped by. Also was 50% sale this past weekend.

Still looking for those connectors? Let me know and I can try to stop by the south SJ location one morning and cut off as much wire for the fusebox and connector. I'll send it to you at cost of the part + shipping. Not looking to make a buck.

Dude, you'd be the best. They seem to be popping up so rarely around here now. Interesting extra relays there, aftermarket alarm system or something?

Also happy to grab you a beer or something anytime you're up in the area!

[amarino]

That's just the later model E21's that have the relays attached to the side of the fuse box. Is that still going to work for you? From the ETM:

2018-04-09_123602.png

[Somjuan]

Shouldn't be a problem at all. Now it makes sense! I just need the engine connector, the blank relay slots get filled by the e36 harness relays. Which are there for...reasons? Just starting with the harness, no idea what they're for yet.

[cgifool]

Hey I picked up a fusebox for you this morning with the first 6 inches of engine and body harness attached. PM me if you still need one.

[Somjuan]

I actually just got the pigtail sent up from Amarino! I'll think about the fusebox, it might be nice to totally rewire one for blade fuses

[Somjuan]

The first prototype just got printed out!



Busted it out of the support material and started to sand the absolute crap out of it. Note to self - don't try to print to exact dimensions to the millimeter. This was about an hour of sanding later. Also not present in the final print - the texture I added to it. Bah.



And a little more up close



This one was printed in PLA because it was way too big for the ABS printer. So once I get the proper dimensions for it to properly integrate with the vents behind it, I'll print it out in black ABS.

[320iAman]

Wiring Harness---Engine Connector both Pieces fuse box side engine side, last time at the yard I did not forget to cut this out also snagged newer pieces to change out the battery power line to inside the fuse box,,new ofc stranded wire there electrics picked up nicely car wide. The Relay Sockets are still available that attach to the side of the fuse box-new, engine plug -connector is NLA from what I have found.
DSCI0278.JPGDSCI0279.JPGDSCI0280.JPG

Randy

[amarino]

Randy I got him like a foot of harness and the engine connector. The relay sockets also tie into engine connector side.

IMG_20180410_173655.jpg

[320iAman]

Good, those relay sockets are Fuel Pump Relay and Main Relay-Lambda Relay. They are still available new-dealer item, the engine plug is NLA. That one I have is a spare one. The pins in the sockets come out and new wires can be put and crimped into the pins.


Randy