N52 Swap

[cwlo]

hubcap, the engine placement right now is pretty much perfect; right up against the firewall with small clearance. I would have liked to be able to move the engine further back because that would have eliminated the pan and pickup mods, but I didn't want to hack up the firewall, and go too radical. I am still using the z4 engine mount arms, that were sectioned and moved 1", with gussetts added since the existing gussets no longer lined up. Any fabbed mount would have to be aluminum, and that brings difficulty in that it would have some very thick sections welded to thinner ones, which gets tricky. Maybe I'll try it one day, but it doesn't offer much benefit. I'm using the green e28 engine mounts.



Hovering, I will check placement with a front pan this weekend. Not sure the lift would even work in this crazy Chicago weather currently.


Getting close to finishing the mk60 ABS retrofit, and then a better air intake. Garry should have the CAN converter configured soon, and I'll give an update on how that all turns out.

[hoveringuy]

https://www.youtube.com/watch?v=679UReY5mwM

Around the 5:36 point. That's the idea!

[hubcapboy]

Hoveringuy knows I’m Gareth, just to clear that up for everyone ;)

A dry sump would be incredible but it’s just insanely cost prohibitive. I cant believe I’m saying that when compared to the rest of the potential budget for this, but not only would it break the piggy bank, there’s so way to locate the scavenge pump (that I’ve seen) that doesn’t delete AC... which is a dealbreaker for me. There’s zero info on electric scavenge pumps.

This approach would just be relocating the sump as people have successfully done on the m5x swaps forever.

The idea is exactly as HG summed it up: a fabricated front sump pan that mimics the e34 pan for the m5x engines and the m20 pan that was factory fitment. The goal would be to end up with clearances similar or better than the M20 pan, which I’ve learned to deal with and have a skid plate to protect. I tried to put my fist under the e34 pan on an s54 swapped e30 last week and couldn’t. That’s terrifying.

Modifying the rear sump pans and the crossmember sounds like it has been working well for people who’ve been doing it, but one wonders why it suddenly went out of production without comment. Looking at the subframe mod I don’t have any concerns. I’m scratching my head a little about the pan modification though. If the cast aluminum pan is structural (and since it appears to be bolted to the trans and block and gusseted in the case of the e34 pan) I’d be concerned that it would have an unknown impact on block stiffness and would affect the tensile capacity along the bottom of the engine-trans assembly that spans between the motor and transmission mounts.

The n5x engines are a completely different animal. There’s absolutely no reason to believe the pan is structural. It’s a simple flat flange against the block, it’s cheap stamped steel on apparently all of the 6 speeds (thanks for that fact Nando), there’s a huge structural girdle under the crank bearings, and there’s no connection to the transmission.

CWLO, why do you believe the engine arms would need to be aluminum? I know there’s a lot of corrosion math that went into this engine to begin with, and a lot of single use aluminum bolts, but it has a painted steel pan and other steel ancillaries bolted to it. The engine arms aren’t even a ground path because they’re isolated by the motor mounts. I was fully expecting to be able to piece them together from steel.

I have the m30 motor mounts in my e30 right now. They seem to be a good rubber upgrade for the originals. Can anyone think of a good reason to use one of the newer designs?

[hubcapboy]

Steve nailed it with finding the Latvian guy. Exactly that, but the steel pan is easier.

[hubcapboy]

I don't want to hijack CWLO's build thread and I don't have a build of my own yet (I do have an N52b30 with a three stage intake and 6 speed sitting on the floor that I sit next to on a bucket and pretend to shift). Should we break off into a general N52 speculation thread? I reached out to a few shops who were pretty wary of the unknowns, and one who was ready to go but not local and would just need blank checks. I was hoping I could farm this out, but now I'm leaning towards finding a rolling shell and mocking it up to see if it's feasible... Once I have an engine packaged into a rolling shell I'd hope to have it swapped and wired and cleaned up professionally. Ordering weird used parts and waiting weeks to see if they fit is something I'm better at than a shop that needs to stay profitable.

[nando]

The pan isn't structural. They just built the dust cover into the pan on the aluminum version. The steel pan uses a separate dust cover.

The arms have to be aluminum because the block is magnesium. steel + magnesium = no bueno. that's why all of the bolts and parts that touch anything on the block that's magnesium are made of either aluminum or plastic (the only exception is inside the block where water contamination isn't a concern).

[hubcapboy]

Got it. There's pretty good guidance on how to protect against contact corrosion elsewhere in BMW's design of the engine and ancillaries (see attached from a pretty complete Mitchell guide to the engine). The construction of the arms isn't important, just avoiding direct contact at the block. I feel like some delrin or aluminum spacers or shims and a new set of factory aluminum bolts would do the trick.

[cwlo]

The front pan setup looks like it would work. Clearance is always a problem on front ones, but you can just go wider and less deep as you mentioned. Pickup tube will need to turn down right away. You can look at the earlier pictures in this thread to see the oil pump with pan removed.


Either a porta-band, or large bandsaw will be helpful in sectioning the pan.


Keep us updated!

[wazzu70]

A front sump oil pan and pickup would be a decent option if you do as you say and make it shorter and wider to prevent it from hanging down so much.

I think a benefit of a subframe that works for rear sump engines is it will work for all M5x-N5x engines and it uses the pan already existing on the engine.

The option where you have to hack up the subframe and pan to make it fit seems way too involved to ever be cost effective though!

[hoveringuy]

A front sump oil pan and pickup would be a decent option if you do as you say and make it shorter and wider to prevent it from hanging down so much.

I think a benefit of a subframe that works for rear sump engines is it will work for all M5x-N5x engines and it uses the pan already existing on the engine.

The option where you have to hack up the subframe and pan to make it fit seems way too involved to ever be cost effective though!

Exactly, if you're going through the trouble to fabricate a new subframe and re-position the sway bar, only to need to modify the rear sump to clear, why not just fabricate the front sump pan and leave the subframe (and sway bar) as-is?

So question, how does the N52 oil level sensing work? No dipstick, so keeping track of oil level with a different pan would be important.

[jwal]

Exactly, if you're going through the trouble to fabricate a new subframe and re-position the sway bar, only to need to modify the rear sump to clear, why not just fabricate the front sump pan and leave the subframe (and sway bar) as-is?



So question, how does the N52 oil level sensing work? No dipstick, so keeping track of oil level with a different pan would be important.

If you're already modifying the pan, I would take an oil level sensor from another pan and drill and tap N52 modified pan to accept it

[wazzu70]

If you're already modifying the pan, I would take an oil level sensor from another pan and drill and tap N52 modified pan to accept it

Or add provision for a dipstick...

[cwlo]

Since the depth of sump will be custom, dipstick is the only way to go.


When I started into this swap, I already had the arc asylum subframe installed, since I had an m54 in the car. If this front sump setup works, it looks like it will be the preferred route. Some baffles in the sump might also be a good idea if it has less depth, and the windage tray might need to be extended. Add a dipstick bung, and you're good to go.

[hoveringuy]

Since the depth of sump will be custom, dipstick is the only way to go.

Yeah, that's what I was getting at. The electronic sensing magic is calibrated to the depth of the stock pan. I prefer dipstick.

[nando]

There's really nothing wrong with the electronic dipstick, but yeah - with a completely modified pan, you'd want to do something else. It's possible to recalibrate but it's not simple.