Garageaholic's E31 850i V10 S85/6 Swap Thread!

[Garageaholic]

Hey Everybody! My name is Frank Macaluso. I live in Vestal NY and have been swapping BMW drivetrains for quite a while. I've done V8 swaps, E30, E21, E36, and I'm ALWAYS looking for someone to come along and let me swap a cool drivetrain into their vintage BMW. I have never had a thread on this swap, which has been long and coming, but I wanted to start while I had some good momentum on the project.


Let me introduce you to my very long and coming S85 V10 swap thread on this 1991 Canadian 850i 6 speed.


Car is a relatively rare sport-seat no frills basic E31. No fancy electronic rear steering, air ride or any of that stuff. It came with dinan suspension (sway bar and springs with Bilstein shocks).


I purchased a csi body kit for it (all bmw factory abs) and had also modified the E36 M3 mirrors to work on the E31 as well.


I bought this car in May of 2013 under the presumption that my friend was going to split the cost. He was to keep the drivetrain (M70 with 6 speed) and I would keep the chassis, with intentions to swap some awesome one day. Not sure what engine at the time, but I eventually chose S85.


In retrospect, he never did anything with the drivetrain and I wish i would have kept it, for the trans alone.


For those of you who appreciate the work I've put into this project, I ask that you consider taking a look at my YT and IG (@garageaholic) and have thus far put together 28 videos of my progress on youtube for this swap alone. I am concurrently completing 2 engine swaps: this E31 S85 and a customer's E30 N54 Twin Turbo swap. Both are a blast, a huge challenge, and have been very rewarding thus far.


Here is the intro video, although not very impressive because I didn’t take much video back in 2013 when I bought the car.




here is the car as we received it












So then I started taking the engine out and stripping almost all pieces that made this car, well a car!





And acquired an S85 Engine from a 85kmile ’07 M5



S85 will be completely refurbished and will come with a GS6-53BZ from an ’07 BMW M6 low mileage, so I know this is good!



And here is the Old and the New Drivetrains!



And test fit it in the E31. And holy moly NOTHING matched up.











So literally, I had to redesign the front end. This entailed a compromise. The compromise here was that I needed to trim some out of the oil pan, convert to rack and pinion steering, and brace up the Rear “front” subframe mount points for the thrust arms, flip and reverse the front sway bar to mount in front of the axle, not to mention a complete redesign of the front subframe.


Oil Pan Trim



Rack and pinion - E46 M3 Rack for RHD, flipped, purple tag

And surprise, more interferences with the steering shaft and the driver side header. So as a result, I needed to have the pinion on the steering shaved down and use a 3/4” DD U joint FR-1963 to clear the header, with some header modifications as well, but again - a compromise, right!?









Rear front subframe removed and braced (thus far, not much bracing here)



Front sway bar flipped and installed in FRONT of the axle, and tacked a prototype arm for relocation of the sway bar link










So here is the before and after, once all of these items have been relocated. Again - All tacked for now. More finalized welding and structural bracing to come.






So then I started moving on to other items of the swap, more restorative items. Brakes!
Decided to go with E83 135i front and rear calipers/pads.
Front rotors are E82 135i and are a relatively easy direct bolt on - Needed spacers, which I had custom made by Angryasssolutions.com. Thanks guys, more pictures to come on that!






Got my spacing set on the front calipers to the stock E31 spindle. Now to get the custom spacers from angryasssolutions.



The rear was a bit more complicated. Rotors here are E39 M5 with E39 M5 e-brake solution. I essentially had to move the rear calipers INWARD approximately 12mm toward the center. This actually worked out pretty good!









Started working rear suspension restoration and was able to press out all of the bushings that were destroyed and replace them, cleaned everything up, and prepped for reinstall, including powder coating the springs. Looks brand new.


















Eddie Rutkauskas gave me a great deal on the upper control arm bushings which are near impossible to find as a bushing alone. Typically runs $500-600 from BMW and you have to replace the entire arm. Terrible. Glad to meet Eddie and help me out!








On the front suspension, Paul Muskof from Moosehead engineering provided an incredible value in the form of an upgrade to the spherical front thrust arm bushings. Thanks Paul!!






For differential, the original diff was open 2.65 - A terrible option. So I acquired a large case E32 750iL diff that’s 3.15 ratio and swapped the rear covers to make it work! I’m not quite sure how 3.15 will work in this application, so I’ve toyed with the idea of getting 3.64 gears and swapping them out later.






Here is the diff ready to go and the springs powder coated and ready for install!



Worked on refurbishing the gas tank - Emptied, cleaned and replaced all lines/rubber and replaced the dual fuel pumps (which were completely 100% gunked up) with a 450lph pump)







Because I went with a single pump, I had to cap off one of the pump outlets, so I chose one! Same for the electrical. I made a note.



Here’s the gas tank installed and strapped up!



In terms of the S85 engine, I already upgraded the throttle bodies, and plan to upgrade the rod bearings and bolts provided by mpowermotorsports. What a great deal I got on these. These guys from https://www.mpowermotorsports.org/ were able to beat the prices on just about every product you can find from ECS or FCP or any of the other big sites. So glad I found these guys. I also plan to replace the vanos HP Line and oil pan gasket…etc. This is all coming up soon!






As far as cosmetics goes, I have updated the mirrors to CSI style, which will match the bumpers as well. I used E36 M3 mirrors and acquired a pair of aluminum cast bases from a member a LONG time ago (like 2014 timeframe)



Bought complete new set of front lights and refurbished the rear tails!






So here is the rear suspension complete









19” M Parallel Wheels Procured! First Pic is the 18” version, 2nd Pic is the 19” version on the other side.




And here are the specs on the wheels and tires. Keep in mind I plan to install 5mm spacers all around, so the offsets below already account for that 5mm. Fronts and Rears below:



Regarding S85 Control, I originally thought to control this via a MSS645 DME with CAS and Key, but decided to spring the extra money and go with a SCS Delta Tornado 2. Below is a snapshot from an IG post, but I did receive the modified harness, DME, and instructions for connecting the body connector into the E31. This is going to be SO easy for first start, I can’t wait to get this going! Take a look below.



So what’s next?! Let’s do some exhaust work! 2.5” Stainless Steel with X Pipe, Dual Resonators, and electronic Cut Off’s



These are Doug’s Headers 2.5” Cutout system. I decided to go with this gate-style set as opposed to the the butterfly valve version for many reasons. Longer lasting, no leaks, 100% seal, and just the reviews were fantastic, so even though they cost quite a bit more than the competition, I decided that these are the way to go. Just got to find a place to install them now!
https://www.summitracing.com/parts/d...4aAlyXEALw_wcB
These come with a wiring bundle and switch, but I will certainly be retrofitting this on an Arduino relay control module to make these one-touch and use some BMW switch. I’m all about making things look like they belong.


Paint - Will go a BMW color, not diamonschwarz. I’m changing the color.
Front subframe weld -
Tie Rod Design -
Headliner
Interior Restoration
S85 First start and integration
S85 Plumbing
Wheels/Tires Polishing/refinishing
Steering column Fabrication to clear headers.

Much more to go thanks for watching guys!!

[ChrisFuture8]

Master, are you accepting pupils as I am humbly kneeling at the front of your gate waiting to be taken in?

[TedBobo]

Wow!

[Garageaholic]

Stay tuned for more coming up! Finishing this puppy up this summer!

[8eights]

Wow!

What he said!

[Adrianl]

What he said!

ya, me too.. this is amazing! What great work!

[rockytt]

This thread should be bookmarked for every yahoo who drifts over with a "hey, want to swap out my e31 motor for an s85 or xxx motor" and then argues while we tell him it's WAY harder than he thinks it will be...

[rjjablo]

Thanks for the picture of the gas tank it explains a lot for something else I am doing.

[ByMW]

this is terrifying brilliant insanity

[thelongeride]

Excellent work.

[Garageaholic]

This thread should be bookmarked for every yahoo who drifts over with a "hey, want to swap out my e31 motor for an s85 or xxx motor" and then argues while we tell him it's WAY harder than he thinks it will be...

It is the most complex swap I've done for the following reasons:
1. Remove drag link steering and install new rack and pinion RHD inverted to work.
a. Because of this, need to solve issues of ackerman and bump steer.
b. Also because of this, steering column must be custom to clear S85 headers.
2. Cut/Weld oil pan for clearance of new Rack and Pinion
3. Thrust Arm Bracing weld, now that the cross member is in the way of the transmission.
4. Move front sway bar location from behind axle to in-front of axle. New welding and bracing.
5. Not to mention, need a completely new front subframe welded in.

A lot of work, which is why it's taken me this long to get to this point. I've decided to install one of hte most maintenance-cursed and expensive engines into quite an expensive vintage car that has millions of rare, hard to find parts! But with time, it's coming together!!

[Garageaholic]

I also realized I had to replace the input shaft on the E32 750il diff. The driveshaft I purchased was a brand new E31 M70/6 driveshaft. This had the same guibo size and obviously the rear half was perfect fitment. The problem is that the 6 bolt CV Joint end that connected to the diff actually was a different size than that on the E32 750IL. So I had to recently swap out the input shafts of the diffs over so that it worked.

And it worked like a charm! Cleaned it up, installed, torqued, and good to go! See differences below. The newly painted one on the right is the E31 M70/6 (larger one). The E32 750iL input shaft is on the left (smaller one).

[Garageaholic]

Thanks! Some more work on the Ebrake stuff. Completed the Franken-ebrake. Works like a charm with the e39 m5 rotors and ebrake hardware, e31 cable, e30 tension bracket, and soon to be installed e82 135i rotors/pads!!


I was actually a bit worried because the curvature of the E39 M5 pads are DIFFERENT than the E31 pads, and as a result instead of the pad making full contact with the inside of the drum, only a small portion would be making contact, and that is bad for a reliable ebrake. Glad the E39 M5 pads fit with the new E31 backing plates and E39 rotors.

[dragon850]

Fantastic work! Can't wait to see more videos!

[adamnur]

Holy crap. This in my mind has always been the only worthy swap into the E31 chassis. Awesome stuff and truly challenging to take on.

[Rickwalk]

A plethora of info here from start to _____ AND the pics do help a immensely. I noticed dust shields ( amazing how brake dust eats the wheels) , tank sub-assy ! Curious as to the relocated components on top of center console hub ??

[bmwmtechnike24]

Love that build.
good job.

can somebody help me with contacting EDDIE RUTKAUSKAS for the bushings.

thank you

[razman850]

Love that build.
good job.

can somebody help me with contacting EDDIE RUTKAUSKAS for the bushings.

thank you

Send Dragon850 a pm.