First start 1975 BMW 2002 m20 swap

[Georges]

Yay! Such a good feeling when they move!

[jimk]

I did Haltech EFI tunes in 2014 for my 325IX M20, speed density.  Modified the injector firing from two drivers to the std 3 drivers, 1-6, 2-5 & 3-4 pairs..  Ran LS1 coil per plug.

[whatyear]

On 4/10/2022 at 12:18 PM, AceAndrew said:

Awesome, happy to see another m20 swap!  Do you have a build thread on here?  
 

Glad to see someone put the headers to hood use.  They are the result of a long long back story. FIY the same fabricator that made the headers is the same that made that exhaust!

 

Ive been working with vibrant and that fabricator on a titanium m20’02 exhaust.  Should also be possible in SS.  Unfortunately, the timing probably won’t work, given you’re further along in the reassembly process.

 

Mind sharing wiring details?  I’m starting that journey right now and looking for examples.

 

I've taken a ton of photos and videos along the way and definitely want to put together a build thread or blog. 

 

exhaust:

Oh man, that m20'02 titanium exhaust would be perfect. If it were a month or 2 out, I'd get on board. I'm leaning towards a bottle-style vibrant resonator + vibrant 6" muffler (if this fits) but any advice would be much appreciated. Or even an existing 2002 2.25 exhaust that I could pair w/ custom downpipe. Do you know if anything like that exists?

 

wiring:
I'd be happy to share pointers for wiring though I'm very much learning myself. I pulled out the existing harness + fuse panel in favor of a MGI Speedware 12 circuit fuse panel. I'm putting this build together circuit by circuit and while I'm no electrical expert, I've put a ton of time into studying the 2002 electrical system.

 

My resources are the Prospero's Garage 2002 wiring diagram, E30 wiki C101 guide, and m20 for dummies swap guide. To get the m20 running, I used the stock m20 engine harness and labeled then chopped the c101 off. I moved only what's necessary to run the engine to a weatherpack connector and will hook up sensors (oil pressure, temp, etc) soon so I have functional gauges. To get the m20 running, you just need to provide power through 3 wires:

- Pin 6 on c101 green wire-- this is the ecu power. It needs 12v when in the ignition/run position

- Pin 7 on c101 thicker green wire-- this is the ignition coil power. It needs 12v when the key is in the ignition/run position

- Pin 18 on c101 black/yellow wire-- this is the starter signal. It needs 12v when the ignition key is in start position

Other notes:

- I have a separate fuel pump relay circuit that gets 12v when the ignition is in accessory/run/start position. I believe you can use the fuel pump relay that's on the m20 harness through c101 pin 13 (green/purple wire) but I'm just using a painless performance fuel relay.

- I provided constant 12v power to the bundle of red wires on the m20 engine harness which I think powers the m20 harness main relay but honestly not sure if this is necessary. I might disconnect and test the results.

 

If you're using the stock fuse panel and 2002 body harness, it's a matter of giving power to the above c101 wires in the correct key positions. Since getting the engine setup, I've setup a headlight circuit w/ relay, horn circuit + relay, fan circuit/switch + relay, turn signals, brakes, reverse light, etc.

 

I'm a big fan of IE and have spent more than I'd care to admit w/ the company. I'd be happy to help in any way with wiring tips as you get into it.

 

fuse panel installed where the heater core went and will be covered by a center console. A downside of the mgi fuse panel is wires come out the sides but I've tidied it up since

Edited April 15, 2022 by whatyear

[whatyear]

Took a 1st drive around the block! I posted the tail end of it on Instagram for those interested: https://www.instagram.com/tv/Cci9g4kJSjW

 

A few notes from the drive: No horrible sounds or fires! Car handles 100x better than I remember on the original, worn suspension. AKG short shifter with the shifter arm I fabricated is super short and a smidge too far up, but not a priority now. I need to bleed the wilwoods a bit more and/or adjust the pedal so they actuate a bit earlier. Can't wait to put some miles on it but will have to be patient til it has an exhaust, alignment and brake break-in.

 

For exhaust, I ended up ordering the Kooglewerks 2.25inch exhaust and will need a down-pipe fabricated to match it w/ the IE headers. I can't wait to hear the m20 with that setup. I've bounced between the ideas of hacking together my own exhaust, going to a local shop that might be turned off by a project or finding a specialty shop. The timing w/ Kooglewerks offering their exhaust is perfect.

 

I've had multiple ppl comment that the m20 engine sounds cam'd (check the IG link above) and someone also mentioned valve timing could just be off. I'm a beginner and learning as I go so definitely curious on opinions here. The engine was a craigslist find and the PO was detailed enough to seem trustworthy but didn't mention an aftermarket cam. Posting this img in the off-chance a cam can be identified by eye ?‍♂️ The stock cams seem to have that bumpy texture 

 

 

[Mike G]

Any paint stripes on either end of the cam? You could measure it yourself with a degree wheel and dial indicator.  Valve timing isn’t adjustable on an M20, only way it could be off is if the head was decked. 

[whatyear]

11 minutes ago, Mike G said:

Any paint stripes on either end of the cam? You could measure it yourself with a degree wheel and dial indicator.  Valve timing isn’t adjustable on an M20, only way it could be off is if the head was decked. 

Good to know about valve timing! Looks like I may have mistyped and that person mentioned "valve adjustment" (feeler gauge & adjusting rocker clearance) but the engine does a distinct lobey sound that I can't explain outside of maybe a performance cam. Next time I have the valve cover off I'll look around for any markings.

[AceAndrew]

More great progress, love it.  Appreciate the wiring tips.  It’ll be slick having the fuse/relays hidden behind the center console, I’m likely doing a variation of that.

 

Cool to hear that you’ll go with that exhaust.  The connection should be pretty seamless and sound fantastic.

 

Looks like you’re going to have a lot of fun driving ahead this summer.

[whatyear]

9 minutes ago, AceAndrew said:

More great progress, love it.  Appreciate the wiring tips.  It’ll be slick having the fuse/relays hidden behind the center console, I’m likely doing a variation of that.

 

Cool to hear that you’ll go with that exhaust.  The connection should be pretty seamless and sound fantastic.

 

Looks like you’re going to have a lot of fun driving ahead this summer.

 

Thanks! Let me know if you run into any issues as you get to wiring.

 

I was considering reaching out to that fabricator to see if they'd do my downpipes but I'm not sure if they'd need my car there to account for engine position and steering clearance ? 

[resra]

Sorry to hijack this post but if anyones interested,

I have a complete M20 that was recently gone through for a friends car that was going to get the swap done by him but in the end he decided to keep it numbers matched. The engine came out of a 1989 BMW 325i. It will come with the wiring harness, the DME, coil etc. 

The head was replaced with a good known used one and in the process the piston tops were cleaned, head professionally checked and cleaned by a head shop locally. All new gaskets installed, all new seals, new water pump, new oil filter, new plugs etc. New Timing belt kit with tensioners etc. All these done by a very reputable local BMW only shop who have been around for many years.

The engine had very low miles to begin with when the car over heated. That head was tossed. It took a long time to source a good crack/warp free head and then all the work. 

The engine currently sits in Dallas. TX and can be bought for only $2200. It is standing on the engine stand. No oil in it (just lub to keep it free moving) and can be put on a pallet/strapped for easy shipment. 

Buyer can pay directly to the friend who this was intended for to begin with. 

 

[D12typ]

On 2/17/2022 at 4:09 AM, whatyear said:

Hey everyone,

 

I'm an infrequent poster but longtime forum member and attendee of the Brisbane meetup. During the pandemic, my m20 swap project has really picked up and I just fired it up for the first time last weekend! A friend and I have done all the work (if it isn't obvious ?). I've taken photos and videos along the way but haven't posted much outside of http:instagram.com/whatyearisthat

 

This car is a rust survivor and we've replaced the entire floor and repaired quite a bit of the body (still need to do the spare wheel well but that can wait). The on-going plan is to store the OG vin-matching engine but swap in an m20 and overhaul basically all systems (goodbye money ?). It'll be a performance oriented sleeper (no fender flares, airbags, body kit-- but you do you) for driving around CA.

 

Anyways, I got the engine test fired (it's the 2nd m20 as the first had no compression) and I'll hook up the custom driveshaft and suspension this weekend. Then brakes, more wiring, exhaust, tires, dial in suspension a bit, test drive, etc

 

 

The car:

- 1975 BMW 2002 saved from the hells of rust, purchased from a man liar in Oregon before I knew better

 

The engine:

- 1990 m20b25 stock

- Basic maintenance- gaskets, seals, timing belt, plugs, wires, coil, etc

- Oil cooler, AC, power steering, fan, heating delete

- throttle body with coolant delete and SSSquid spacer

- received racing pros chip but going to run stock ecu for a while

- IE m20 swap headers

- 1990 honda 3 row aluminum radiator w/ Mishimoto fan + relay kit

 

Suspension/drivetrain:

- Ground Control coilovers

- Reinforced front subframe from IE

- IE roll center spacers

- Catuned Monster adjustable rear subframe with 3.93 e30 diff

- Getrag 260/5 w/ custom mounts

- ACG tunnel-mounted shifter

- Shortened and balanced e30 driveshaft

 

Brakes:

- IE big brake kit front and rear

- Chase bays brake booster delete & e30 rear brake line set, handmade front line

 

Wheels:

Rota 15x7 mesh

 

MGI Speedware 12 circuit fuse box-- slowly building my own harness but using the stock m20 engine harness

 

**Not sure about exhaust or wheels yet-- any advice??

If you're still reading, thanks for checking out my build!

 

 

hey looking good, any updates? 
 

How did you go about fitting the getrag260? Was there any modification required to the underside to make it fit? 
 

appreciate any advice 

[whatyear]

On 7/14/2022 at 4:43 PM, D12typ said:

 

hey looking good, any updates? 
 

How did you go about fitting the getrag260? Was there any modification required to the underside to make it fit? 
 

appreciate any advice 

 

Fitting the g260 in the tunnel  

Modifying the tunnel will greatly depend on your motor mount setup. I used the Classic Daily m20 swap kit that puts the m20 engine low and to the rear. It’s a low center of gravity but does create some clearance issues.

 

To fit the g260 well, I found that I needed to:

• Wail on the firewall area of the transmission tunnel with a dead blow hammer and also used a jack stand + small 2x4 for some areas to expand the diameter 2-3 inches. It’s thick metal, but if you take your time it’ll work and not look all banged up.
• Expand the tunnel near the clutch slave cylinder to allow a wrench to remove the cylinder. Without doing this servicing will be a big pain down the road.
• For the G260 to clear the steering, I needed a custom center link from 2002Underground (not sure if they’re 100% open but were super helpful) and shaved down the flywheel cover on the G260. It’s a tight fit now and without that custom center link, it’d be a ton of extra work.

I made a simple selector rod and kept the shifter in the stock position, with some reinforced tabs to run the AKG e30 short shifter. It’s a comically short shift but feels great w/ no vibration.

Progress:

Other than that, I’ve been pretty busy moving apartments and moving from my outdoor work space to a new garage. But I have put time into a few areas as I prepare to move the 2002 from the workspace to my new apartment garage.

 

Gauges:

• Speedhut 120mph GPS gauge- they run a few sales through the year
• IE tach adapter. This takes your ignition coil signal and converts it for the stock tach. You can do this w/ a resistor but I found a used converter on eBay for a deal and might hook up a shift light at some time
• Swapped in a switch that controls a strip of yellow LEDs to light up the fuel/temp gauge & tach. They’re a bit brighter than the yellow Speedhut lights but match well.
• I'm not sure if I'll wire up the fuel tank level sender. It wont be accurate w/ the e21 fuel pump that sits high but might be better than nothing? I have some ideas for other temp/pressure gauges.

Interior:

• Test fit the interior and made a wooden rear seat support (took a shortcut here vs the replacing the rusted stock support).
• Found a deal on an Esty kit that I'll install after I put time into getting the car running well
• Setup the IE pedal. It's a tight fit with the expanded tunnel but feels great w/ the universal lokar throttle cable

Exhaust:

After researching a bunch of exhaust options, I ended up going with a setup that I’m pysched to hear on the car. I’ve only driven it with the IE m20 swap headers  on a test drive and to a shop to install the full exhaust earlier this week.

 

The exhaust setup starts at the IE m20 swap headers to a custom stainless downpipe/collector w/ O2 bung and ends in a full Kooglewerks exhaust- center exit. The exhaust is 2.25 inch from header output back to the tip. I don’t plan to go super high HP with the m20 engine so I opted for 2.25 and hoping it'll sound great w/ some performance gain. But we’ll see! this is my first build ?  The exhaust should be done in a week or 2 and then it goes to my new place.

 

Pardon the bumpers- I don't love the other options and the goofy ass bumpers add some charm  I'm also paying $25/month insurance w/ basically no coverage so a bit of bumper doesn't hurt. I'm thinking about calling Hagerty but would love advice there. 

Edited July 16, 2022 by whatyear

[Mike G]

I’m excited to hear that exhaust too. You mentioned a new garage, if that’s where the car will be parked at night it opens up some options on insurance, I’m with State Farm on no mileage restriction and a ludicrous amount of coverage required by my umbrella policy for $50 a month. They let me turn off everything but comprehensive through the winter when it’s stored to save a couple bucks too. 

[whatyear]

11 hours ago, Mike G said:

I’m excited to hear that exhaust too. You mentioned a new garage, if that’s where the car will be parked at night it opens up some options on insurance, I’m with State Farm on no mileage restriction and a ludicrous amount of coverage required by my umbrella policy for $50 a month. They let me turn off everything but comprehensive through the winter when it’s stored to save a couple bucks too. 

Awesome, thanks! I'll see if my insurance offers something similar, mostly to cover the investment into parts in the car as the body isn't in concourse shape  

[BGB]

Where in SF are you? Would love to come by and take a look ?

[Mike G]

Updates? Exhaust video?