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M20 Triple weber build x2

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75duce - thank you for the pictures, the more pictures I collect the better. Do you have any of the earlier manifold?

Sorry not many updates recently. Been finding out that there needs to be more hours in a day with full time @ IE, full time @ school, and a family (7 month old son loves sitting in the 2002).

Groma/Mano update ---- will be getting back to the Groma car next week, plan is to now have a completely shaved bay, pics to follow.

Me/IE update

snapped a better shot of the car, not bad for original paint.


---- turning focus to more immediate problems than the engine. Am rebuilding the front and rear subframes/suspension. List as follows....

FRONT subframe -- weekend warrior build (not overkill on street but certainly stiffer than stock.)

- IE Driver's side motor mount weld in plate

- IE front urethane bushing kit (inner and outer control arm bushings, radius rod bushings)

- OEM idler arm bushings

- IE urethane steering coupler

- OEM tie rods and track rods

- Rebuilt steering box

- Bilstein Sport Shocks

- IE stage 2 springs

- OEM lower ball joints

- GROMA reinforced lower control arms

- IE 22mm front swaybar DropCenter (clears M20 oil pan)

- OEM/IE HD rubber motor mount kit.

The steering box I had ready to go was snagged for a customer so what better opportunity to learn how to rebuild one myself. The 2002 steering box mechanism simply consists of a steel roller shaft mated to a worm gear, these parts are now NLA so if your gears are pitted/ground (see below) you might want to consider getting a rebuilt box (or buying a couple other used boxes in hopes of piecing together a good one)

Steering box diagram via RealOEM.


Notice the flat spot on the inside of the right roller shaft, this would indicate it would make a good paperweight!


Notice the grinding wear on the left worm gear, also good for stacks of papers.


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  • 4 weeks later...

How is the front going to line up with the strut since the oil pan occupies that space? Custom subframe?

I can't wait to see the crazy shift linkage that'll have to come from a longer tranny + moving the engine back 8" or so...and the subframe/engine mounting system(direct to the body?)

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  • 1 month later...

Manimal - I believe the oilpan is going to sit as tight as it can to the backside of the subframe.

So I've finished up the steering box and have some tidbits worth mentioning.

Here's how it started. Nicely covered with gear box oil, yummy!


Taking the pitman arm off was pretty entertaining. We stuck the box upside down in a bearing splitter and used a press on the bottom of the box, it separated with a pretty good bang.

After disassembling about 3 used boxes for parts I had enough pieces to make one good box (this is one reason why it might actually be cheaper to just buy a rebuilt box.).

Replacing the upper and lower seals is so much cheaper if you go through an oil seal supplier (I used Colonial Seal) rather than a dealership. BMW list is $13-$15 per seal vs. $2-$3 from Colonial (you simply need the dimensions printed on the seals). Unfortunately the plastic bearing cages and their races are only available through BMW (cages $35 each and the races $45-$50 each). I called a local bearing guru (old school guy with records dating back from the stone age) and gave him the BMW part numbers for the bearings/races as well as the manufacturer's printed part #'s (SKF in this case), he said that they have not been available for some time (through sources other than BMW) and that they appeared to have been designed for the aeronautics industry, pretty interesting stuff. I used the best races and bearings out of the 3 boxes and called it good.

I bought new 8x25 hex bolts and wave washers through BMW because they were relatively cheap and came cadmium plated.

Prepped and painted the box, top cap, and side cap with 3 coats of caliper paint.

Reassembly was pretty easy, just retraced my dissasembly procedure. I did take a skotch-brite pad to the shim plates as they were pretty crusty.


When putting the worm gear back in I was sure to line up the gear mark with the case mark before tapping in the vertical gear assembly in (simultaneously lining up the two marks on the bottom). This insured that the steering position will be at top dead center once everything is in place.



And the finished box almost ready for action.


The finishing touches were the cadmium plated steering coupler brackets that Draco ('02faq member) gave me, along with the urethane steering coupler. Nyloc nuts used all the way around.


Ready to go!


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People have looked into a dry sump setup for the m20... cheapest options seem to be around $2500 (ouch)

Tinker Engineering - 2014


Mica - 2000 BMW 323i - The one that started it all

Fiona - 1975 BMW 2002 - The Definition of Project Creep

Heidi - 1988 BMW M5 - The piece of BMW history

Silvia - 2013 Subaru WRX - Stock, for now

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  • 3 weeks later...

A dry sump would be neat, but the Mano seems to have something else now lined up, not really going to follow that up until something materializes.


So for my build the entire idea is to make it as stock appearing on the outside as possible, but I'll obviously some pretty decent stopping power. My setup will be as follows.


I'll be running the our Ireland Engineering BBK volvo setup which includes....
*E21 Small bearing hubs -- The spindle of the E21 strut are the same dimensions as the one found on the 2002, allowing me to ditch the ancient hub over rotor assembly. Small bearing hubs are found on post 77 US cars, but as they are becoming increasingly difficult to find, we (IE) decided it would be more cost effective and convenient to just make our own using the same dimensions.
*12x57 thread in studs -- no longer need the stock press in studs.
*Wheel bearings
*dust cap
*Re drilled Volvo based remanned calipers
*E21 vented rotors (USA 1977 only or any E21 euro 323. For some unknowable reason BMW USA switched back to solid rotors after 1977.
*pads -- I'll be running some generic Ceramic performance pads.

First step, got a little too happy with the locktite


Interesting comparo of the E21 hub vs the one found on a Panoz Esperante GTS Spec Racer.


Pounding in the races. If you are not confident DO NOT put in races like this, you will screw it up. Yes, there is a tool to press in races. I used a similar sized socket and rubber hammer.


Caliper size camparo. Note the caliper width for the rotor, the Volvo caliper obviously is wider allowing for the vented disk.


Rotor size comparo showing my 'Big rotor' for the 2002 as compared to a couple of the E30 BBK rotors.


Test fit.


Here's the beauty of a properly flush caliper fitment due to the repositioned mounting holes. While it is possible to run the calipers without repositioning the mounting holes, the pads just do not sit flush with the rotor and the caliper takes up more space inside the wheel. Some people opt to use unchanged calipers since it's a bit cheaper, but I wanted to do it right.


Edited by AceAndrew
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---To again comply with the sleeper approach I am going to be running the 250mm rear drum setup from the E21.

Dissassembly of the rear hub requires removal the rear stub axle nut. It's not the easiest nut to remove. I got them off by using a good amount of penetrating oil and a air gun.

Removal of the rear hub. I used a rubber hammer and rotated the hub while gently tapping the backside. A proper puller is the more generally accepted route.


Hubs off and studs pressed out, off to be zinc coated.


Comparo of the 230mm standard drums found on the 2002 as compared to the 250mm drums from the E21.


Everything ready to go. Included from CWmarsh (thanks again Chris!) whom I bought the setup from on the FAQ was the parking brake cables from the 2002 Turbo (slightly longer). Depending on how much one's E-brake line has been previously adjusted (i.e. shortened) one might need to run these.


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  • 2 weeks later...

Pretty stoked, I just had a 4-speed transmission from a euro 323 (Getrag 242) drop in my lap (Thank you Matt of Ronin Autowerks!). which can be combined with the 320i 5speed (getrag 245 "US spec") to create a cost efficient way of getting a 5-speed that has the M20 compatible bell housing and fit in the tranny tunnel without needing to hack it up ( a la' Getrag 260). Once I get a chance I'll be meeting up with Rob at Precision Gearing and do a write up.

In my opinion, for any standard M20 swap, it is a crime to hack up the sheet metal of the tranny tunnel and is simply unnecessary. The 323 5speed (Getrag 245 'euro spec') or the hybrid 242/245 type going on this car are more than capable of handling the power and don't require body surgery. The Hybrid 242/245 Getrag is also relatively affordable.

The guys at Stanceworks work kind enough to stop by a little while ago...


EDIT: Tom -- sorry I never replied to your post, frankly I'm no where near starting to eyeball fitment, but we have the same mindset. I want to do as little cutting as humanly possible.

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  • 1 month later...


Done that a few times but I used a 242 4 speed from a euro 316 E21 to convert a 245/10 close(323i) to M10.

I have some 245 M20 bellhousing´s laying around anyone interested in a trade?

Shipping could be a killer tough...


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Pico, thanks, it's good to hear from another source that it's do-able. How abundant are 323 5-speed boxes over there?


Parts finally back from powdercoaters, was worth the wait, they did an awesome job. Went with a black semi-gloss.

Was a LONG Saturday getting everything put together, luckily Jeremy came in as well.

Here's the end of day shot, should get everything in the car this coming Saturday. Then it's time to start thinking about the M20 again.


BMW 2002 strut build ....

The bare powdercoated struts (obviously the threads on top and the spindle were masked.


Had the steering arm zinced, put in new ball joints, and greased up the inside (used some bearing grease).


Here's an arm I pulled apart (originally must have lived in a rainy climate). Good lesson on why you should grease the insides!


Greased up the hub and bearings....


after putting on the grooved washer I tightened down the castle nut nice and tight before backing off one tooth and sliding the cotter pin through (after a couple of days driving, I'll go back in and tighten it down some more)


Next were the Bilstein HD shocks, these went in pretty smoothly except getting a good handle on the gland nut was a PITA. I've heard that you can smear a thin coat of ATF on the insert to prevent corrosion, however with the risk that the breather at the bottom of the insert might get blocked I opted to put them dry. Guess time will tell.

Bolted the steering arm to the bottom of the strut and safety wired the bolts. The little bolts are getting pretty spendy at $6.25 each BMW list price.


How struts will sit until they go into the car. I'll be reusing the Ireland Engineering Stage 1 springs along with new strut bearings and some fixed camber plates. No need to go coilovers unless I want a track car.


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And now the rear suspension ....

1. BMW 2002 Rear Subframe reassembly (Street Performance oriented)

Written by myself, Andrew Adams, with much help and teaching from Jeremy. This is intended to go up on our expanding Ireland Engineering Tech Section to help answer some of the questions we get asked regularly.

BIG DISCLAIMER: I am not responsible for your screw-ups.

GENERAL TIP:  Never fully torque down a bolt intended to hold a pivoting bushing into place until after the full weight of the car is applied.  (This is generally why you’ll see someone stress out and say their car is sitting like a 4x4 after going through their suspension)


After getting everything back from powdercoating I started piecing together the rear subframe.

First up were the new OEM rear subframe mounts w/ Ireland Engineering urethane inserts.  The inserts go in through the top (you’ll need an exacto knife to cut through the thin rubber webbing inside the mount.  Curiously I bought the bolts from BMW, and they came stamped 9.8 (seen 8.8 and 10.9, but never a 9.8).  Bolted the mounts to the frame. 


I started with the rear wheel bearings (they are not as weird as the E30 rears). 


Upon removal of the old bearings you’ll find a shim and sleeve, keep those bagged appropriately.  The shims are specific to the trailing arm, and if you lose them it’s a PITA to calculate the correct size replacement needed (BMW had a number of thicknesses used.)


For reassembly I started with the inner bearing, (press was oh-so-nice).  Packed the bearing with grease. When pressing in the new bearings I made sure to use an appropriately sized hollow tube (you want the pressure applied on the outside ring of the bearing, pressure applied to the center sleeve will destroy the bearing (or hasten it’s demise).



For the outside I put in the sleeve and placed the shim on the inside shoulder then pressed in the greased bearing.  With the bearings in, I layered some grease up to act as the grease reservoir before tapping in the seals (don’t want to tap the seals down much past the lip as it encroaches on the grease reservoir).



Next are the stub axels.  Often upon removal the threads can get bunged up when someone mistakenly hammers them head on. Sometimes (but certainly not always if its too bad) this can be righted by filing the threads or chasing them with a thread chaser.  Try and get these as clean as possible before pressing back in (I used scotch bright).  Simply press these back in (there will be two major points of tension as it’s pressed in).



After the stub axle went on, I pressed in the shock absorber stud back into its knurled hole on the trialing arm and bolted on the brake drum backing plate (in the case, one of the 250mm sized units).  I made sure to situate the plates so that the small hole meant for the E-brake cable is on the forward side in relation to the trailing arms. The forward brake shoe retaining pin needs to be put through it’s hole at this point as well (there is not enough clearance to the trailing arm after the backing plate is bolted down.  Bolts were 8x25 with a lock washer  


Next on were the wheel hubs (also zinc plated), I tapped these on with a rubber mallet.  The infamous axle stud was then hand tightened down (the final torquing won’t be done until the car is on the ground.)


The last part of the trailing arms (before attaching the arm to the subframe) is to press in the Ireland Engineering urethane trailing bushings (part of the rear bushing kit). When looking at a single trailing arm, the thicker end bushing needs to be on the outside.  I liberally lubed up the bushings with the supplied grease (super sticky) prior to squeezing them in (a C-clamp worked nicely).


Finally attached the trailing arms to the subframe. BigNote:  I’ve seen this covered before, but if you’re having your standard 2002 trailing arms boxed in, then you need to make sure who-ever is doing the welding is doing so on either a jig or an actual subframe.  If not, you’ll have some arms that are pinched and askew.  Depending on your trailing arms, it might be nice to have a friend around for extra muscle.  The trailing arm bolts are 12x1.5x90mm.


Next up was the brake hard line. Started with a 20”line of bubble-flared brake line. 1st bend w/ downward angle, then another bend to run the brake line along the inner arm before ending with another bend approximately where the stock line would be. Used a bit of split rubber tubing to wrap around the hardline where it goes into the retaining hook and pinch it closed. Bubble flared fittings do NOT need teflon tape since the flare acts as the seal, however Pipethread brakeline ends DO need teflon tape.


The last bit for the rear subframe is the Ireland Eng. 22mm sway bar. The endlinks are pretty straightforward, though it's worth noting that they are fully adjustable (using sliders), the more you choke up, the stiffer it acts.


The pivot bushings are a royal PITA, but with a little time and patience, they should be conquerable. The first thing is to make sure the U bracket retainer on the subframe is perfectly parallel (if not, squish it between to solid objects [like aluminum blocks] and use a hammer to straighten). Slipped the urethane bushing (w/ liberal amounts of grease) and fit the U-clamp in the bottom over the sway bar Next I started with a long-ish 8mm bolt and started cinching down enough to start a shorter bolt in the adjacent hole, repeated with ever smaller 8mm bolts. With the help of a clamp and muscle, the bracket was cinched to a snug fit.




And after that the subframe is ready to go up in the car!


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