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E38 S62 Swap Underway

145K views 405 replies 65 participants last post by  blackknight530i 
#1 ·
Hey guys, I wanted to let you guys now about the transformation that is currently underway on my recently purchased 2001 740i non-sport. I’ve been doing research on this project for about 6 months or so before deciding to pull the trigger on it and while some people will understand why I wanted to, others will surely claim that it wasn’t worth the money. I’ll put it this way, yes it is quite expensive, but I could have gone out and spent 3-4 times as much for a new 3 or 5 series and not been nearly as happy. So I say that with my daily driver ’03 530i sport and my ’01 ///M7, I won’t need a new car for a very long time.


20131003_171701 by blackknighti30, on Flickr

I was wanting to wait until I had the project completed before posting, because I know how these usually start. People say, “Can an S62 swap in an e38 work?” or, “How much will it cost?” or they even say, “This is going to happen” and it never pans out, so I wanted to tell people after it was done. Now that I’m at least half-way complete on this project and don’t have any intentions of backing out since I can’t exactly put the old engine back in, I figured I’d go ahead and share.

The car started out as a 2001 740i non-sport with 189k miles and bad timing chain guides. The engine runs, but I didn’t want it to jump time so I never really got it up more than about 35 mph while moving it from the transporter to my house. The transmission shifted well and it rode nice and smooth. It’s a pretty clean car that had records for the last 90k miles from the previous owner.


20131004_082419 by blackknighti30, on Flickr


20131004_082434 by blackknighti30, on Flickr

The engine came from a member here on M5board.com who’s M5 had an unfortunate encounter with a guard rail while stretching its legs. The engine was an assembly line motor from 2003 that he had installed 42k miles ago and should be a great motor for my swap. It had absolutely no leaks and only a couple pulleys and the fan clutch/fan were damaged from the radiator pressing into them. It also had a new clutch installed only 300 miles ago. The engine also came still attached to the subframe and included the steering box, which we are hopefully going to be able to swap over.

Now on to the actual build.

First things first, we needed to pull out the old engine and transmission. We decided to disconnect all the hoses, wires, etc. and lift the car off of the subframe with the engine/transmission still attached. This was a little complicated as it was difficult getting the steering column disconnected from the steering box due to access issues, but we were successful.

20131205_075659 by blackknighti30, on Flickr


20131205_075626 by blackknighti30, on Flickr


20131205_075618 by blackknighti30, on Flickr

Here’s the now cleared engine bay and transmission tunnel:

20131205_075646 by blackknighti30, on Flickr


20131205_075634 by blackknighti30, on Flickr

Out with the old… In with the New:


20131206_180018 by blackknighti30, on Flickr

After we got the subframe out, we separated the engine and transmission from it and put the engine on the rack. We reattached the subframe and rolled the car out to do some pressure washing of the engine bay. It took three applications of purple power to get all the oil that had covered the bay, but eventually it was almost new.

We then began considering the possibility of swapping the steering box from the M5 into the 740i. We thought about swapping the M5 subframe first as it would already have the correct mounting brackets for the M5 steering box, but we found out that it had been slightly tweaked during its run in with the guard rail. We also noticed that many of the brackets that hold other various things, were in the wrong places or too short/long, so we decided that we are going to go back to the e38 subframe and just modify the brackets to the steering box. This is where we left off before this coming weekend when we attempt this.

Back to the engine…

The other thing we noticed was that the exhaust is a little bit different. Since I’m working with a M62TU exhaust system that only has two pipes going to the headers rather than the four that the M62 has, we need to figure out a way to make the S62 headers collect into the M62TU exhaust. One option considered was to use the M62TU headers with pre-cats on the S62, but this seems like a restriction that should be avoided. Another option is to find a M62 version exhaust system and install it directly to the S62 headers. This is also counterproductive since the M62 exhaust was much more restrictive leaving the cats than the M62TU exhaust. The solution I’ve come to now, but haven’t done yet, is to take the collectors from the M62 exhaust before the main cats and weld them onto the M62TU exhaust. This would keep the larger exhaust sections of the M62TU while removing the pre-cats from the system. Ideally I would have liked to have found the cat sections from an M5 and adapted those since the cats are much larger, but that will have to wait a while (I did mention this is an expensive swap, didn’t I?). The rest of the exhaust for now will be the stock M62TU until I figure out what to do in the future.

I also needed to install a new fuel pump since the M5 requires 72.5psi or 5 bar rather than the paltry 48psi for the M62TU. I bought a Walbro 255lph pump and swapped it over. This was pretty straightforward. I will also be installing a new M5 fuel filter and pressure regulator.

In regards to the pedals, I had bought a pedal set that ended up being for a pre-facelift 5-series rather than a post-facelift and therefore, there were a few differences in where the positions switches and clutch master cylinder are located compared to the facelift pedal set in the 740i. We needed to cut the brake pedal down to the size of the manual one and it worked. I just need to install the new clutch master cylinder and it should be ready to put back in the car.

The shifter arm, which is unavailable from BMW anymore, is made up from two broken 5-series parts welded together in order to extend it. I was able to order the selector rod, but it’s been a few weeks now and BMW still doesn’t know an ETA of when it will arrive, so we improvised and had the 540i selector rod extended as well. Both the arm and the selector rod needed to be extended 15mm. If I ever receive the part from BMW, I can swap it out, but honestly, I’m not sure it needs to be. The shifter itself is the one from the e60 545i and has a new shift boot and ZHP knob.

The “sport” button from the M5 will be installed in the console as well. This should be pretty simple since it is just two wires that need to be run from the console to the E-box. Also, since the servotronic steering control is actually handled by the DME on the M5 rather than the GM on the 740i, it should just be a matter of swapping which connecter in the driver side wheel well it goes to. They use the same type of barrel plug.

Speaking of wiring, I’m still working on this, but most of it should not need to be changed if you are using a facelift e38. I did however find that the fuel pump relay wire is on a different connector in the e38 than it is on the M5. The easiest way I found to connect it is to remove it from the module it is in and swap it over to the correct pin on the M5 module connector. The other option is to splice a round connector pin and place it in the white engine plug in the place where the M5 expects it. I will also need to run a wire from the clutch pedal position switch to the DME, but that should be pretty easy. Almost every other sensor wire and such (save for a few I haven’t messed with yet) are attached to the main engine harness including the reverse switch and gear position switch on the transmission and all other sensors mounted on the engine, so it is fairly plug and play.

Instrument cluster will be from an M5, but I am still waiting on my M35080 programmer so I can get the mileage corrected.

Motor mounts will need to be swapped with either M5 or 750iL mounts (they’re the same) as they are stiffer than the 740i/540i mounts.

Driveshaft is at Carolina Driveline in Spartanburg, SC getting extended and should be done next week or so.

I hope to have the engine and transmission installed by this weekend, but I won’t be able to have the car running until after the holidays. I’ll update the thread as I go along from now on. Pictures will likely be added to the appropriate places in the post as well.

Additional pictures: E38 S62 Swap - a set on Flickr
 
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#4 ·
Thanks guys. I've been reading about so many S62 swaps for quite a while before I decided to undertake this project, but nobody had posted that many details on them. A few pictures and such, but my mechanic and I are doing a lot of it by trying things out as we go. I'm so excited about it and I hope to have it on the road by the end of the year or within the first week or two of 2014.
 
#5 ·
Oh, and what's the consensus on what I should call it? I know using M7 is a bit sacred, but by the time I'm done with it, it should be pretty close to one.
 
#8 ·
LSD is on the to-do list, but suspension will probably be B&G Sport springs with M-tech struts and a rear sway bar added. Last I checked, you didn't need to have Dinan suspension to have an M5, LOL. Also will be shadowlining and some style 95's eventually when the nearly brand new Michelin Pilot Sport AS+'s that came on the car wear out. I've also considered 750m or 750i m or M750i. Those would be easy to get trunk badges for.
 
#9 ·
i wouldn't go 750 because it may give the wrong impression. Especially since the e38 did indeed make a 750. Also technically the motor is a 4.9. On another note i see no problem with ///M7
 
#11 ·
I know what you mean that they made a 750, but I don't think there will be any mistaking since they never brought the 750i to the US, only the iL. Also, it's like 4.944L, which is close enough to a 5.0L, plus many technical documents call it a 5.0L. It would be very hard to find a 749 badge, LOL.
 
#18 ·
Yeah totally agree 750 M is way better than m7
 
#13 ·
Maybe 750si since it has an M build engine in a non-M car like the 850Csi did.

A guy with a black 7 on bimmerforums.com already is using the Darth name and I wouldn't want to spoil his fun.
 
#21 ·
Looks like the ideas are narrowing down to 750 M or M7, other than the Frank reference, LOL. I don't think I"m going with a "Frank" trunk badge. I guess what I'm getting at is that I'm looking for a trunk badge, not really a name. A name for a car only really lives on the forums anyways.
 
#23 ·
Well, 740i doesn't really apply anymore, but I did think about removing entirely, but I want something subtle. Maybe just an ///M badge would suffice.
 
#27 ·
Here is a clip of or 2 swaps doing a test run. 2 total different cars.
8 has 391 diff, dinan exhaust, uuc flywheel and clutch.
7 kept the 293 diff, eisenmann exhaust, stock clutch, AFE cold air intake.

M7 and M8 run - YouTube
 
#29 ·
Cura, that e38 in that video is what inspired me to do this swap. He made it look so good. He also decided to call it an M7. The only thing is, I wanted more pics of the engine bay after the swap was completed. I had questions like how the air boxes fit, how he mounted the oil filter housing in order to clear the air box on the driver side, etc. There are plenty of photos of the e31 S62 swaps engine bays, but not e38 and most of the e38 pics there are have just a couple cone filters mounted to the MAFs. Anyways, Clemster is hooking me up with some M5 airboxes so we'll see. Another question I haven't gotten an answer to is why the M5 radiator shroud/expansion tank is different than the standard 5/7/8 series shroud/tank. I'm hoping I can get away with using the e38 one since people really charge a lot for M5 shrouds.
 
#30 ·
I will reach out to him for you and get you some pics. In regards to the radiator the m5 system is a much better system that's the reason for using it. Reach out to clemster he might have one available, I may be changing my to aluminum will keep you posted if I will sell it.
Yes that's johns car.
 
#31 ·
Cura, so the radiator is actually different? I couldn't see that much difference between them, but I've never really seen an M5 radiator in person. I should be good for a while on the 740i radiator though, right? I don't plan on tracking it or driving it hard for a while.

Yeah, that'd be great if you could get some more pics of John's swap. Thanks.
 
#34 ·
You stand a risk of the radiator from the 7 exploding the m5 radiator was design to handle the pressure from the motor.
 
#33 ·
TopEnd, those are the pics I'd seen before, but it wasn't completed at that stage.
 
#36 ·
From what I can tell, both systems work at 2 bar.
 
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