N52 Swap Discussion

[Caperix]

Yes the small 90 degree elbow with a heater plug held on with 2 torx screws on the back of the intake. How long have you had your engine for, the recall came out a few years ago so it may have been replaced before you got it.

[hubcapboy]

Make sure to replace the pcv elbow on the intake, they are under a recall for melting. I have seen some bad enough to damage the intake manifold.
With the swap parts being developed is everything based around the early n52? I know the differences are minimal but things like the different pcv setup on the latter n52k could make oil pan development easier as it no longer needs the drain. Is the ews delete tune only for msv70 or will it work on msv80 as well?

Help me nail down which part you mean by the PCV elbow. The small heating element that’s opposite the butterfly? I cleaned and inspected mine before reassembling and it looked new, but I’ll take a closer look if that’s the one you’re talking about.

Hoveringuy has a late/plastic, I have an early/magnesium. The drain was definitely another step for my oil pan, but I just drilled a hole and plumbed it into roughly the same location. The late works much better for anyone switching to the n54 intake because they won’t have anywhere to *put* the early PCV system.

[Nowayman]

I’ll be joining this thread/starting my own shortly. We definitely need a sub forum for this engine! It’s going in my vert👍

[Caperix]

Make sure to replace the pcv elbow on the intake, they are under a recall for melting. I have seen some bad enough to damage the intake manifold.
With the swap parts being developed is everything based around the early n52? I know the differences are minimal but things like the different pcv setup on the latter n52k could make oil pan development easier as it no longer needs the drain. Is the ews delete tune only for msv70 or will it work on msv80 as well?

[hubcapboy]

*IF ANYONE KNOWS HOW TO GET IN TOUCH WITH AN ADMIN OR MODERATOR WHO CAN ADD A SUB-FORUM FOR THIS ENGINE... I'D LIKE TO PRESENT MY CASE*

The second post in this thread bought this up, but it seemed like a big ask at the time. We're approaching the number of posts in the S38 sub-forum *just in this post* and I'd LOVE to start getting this stuff sorted out into stickies for each system (Cooling, wiring, mounting, intakes, etc).

We could also start to break out build threads for the (at least) four cars that are going, because I bet this is getting confusing if you don't know everyone.

I'm crazy jealous of that e91... Trevbot kindly forgot to remind everyone that I sold this engine already in a BMW once already.

That being said, here are the random things I've learned in the last 24 hours.

Magnesium and plastic valve covers have exclusive ignition/injection wiring harnesses. The magnesium valve cover has a long tray that fits nicely:



In this harness, the umbilical from the DME enters between cyl 4&5, and then the injection wiring is routed around the back of the engine to the injector rail. The plastic valve cover harness management is shorter, and doesn't fit around the bosses on the mag:



This is a screenshot from a plastic to mag cover conversion video here: https://www.youtube.com/watch?v=5uedpKybBEw&t=1835s and please ignore that the cover is black... he painted it black. that's magnesium. the other thing you notice here is that the wiring crosses over the top of the valve cover instead of looping around the back, and the umbilical *enters* from the back corner. There may be more permutations resulting in even more harness detailing, because the exit location of the umbilical is tied to the side of the car that the DME is on, and several cars came with both plastic and mag cover engines. I think to do this right I'm going to be cracking open the ignition tray and installing the longer (X3 in my case) harness into it, and then using the rear port for the exit. There's no reason for the injector side wiring to pass through that tray any more, which means I can run that harness separately and route it to the DME. I probably don't even have to use my x3 injector harness in that case.

Last night's project after the kids were asleep was rebuilding the intake manifold and PCV:



I'm pretty sure my large DISA flap is shot, so I'm working on that, but luckily it's the easy one to swap so it's not critical path. I learned while doing this that there are two version of the 3-stage manifold. one of them has the single pcv port you can see in the center of the "big tube" above. The other has two ports which immediately Y together (discussion here: https://www.e90post.com/forums/showt...php?t=997384):



Why are they different? who knows. I didn't track down which was earlier or later, or which models, had which one, but it's completely internal to the engine so it was some kind of design revision. If I had to guess I'd say having the port immediately opposite the throttle body caused vacuum issues for the PCV, and a single offset port wasn't ideal, but also didn't warrant a second heater (the difference between the big and small port is the larger one gets a heating element). I ended up with the Y hose in my order, but re-used my single hose. Maybe my intake wasn't original to the engine?


My goal with Habla for the time being is to delay him as long as possible to probe him for detailed pictures of factory installations... he's already done me one favor by posting that underhood shot and reminding me that the wiring tray goes RIGHT over the middle of the engine. I was scratching my head last night trying to figure out how the factory routing worked behind the engine... and this morning I realized that it DIDN'T, which leaves me with that unsightly braid-covered PCV hose hanging over the top of the intake (it connects to the boot just in front of the butterfly valve. It's hidden under the cowl of the e90, but I'm going to have to find a replacement and snake it somewhere else.

[Trevbot]

Well damn, that one is too nice and makes a great babymobile.

When progress slows the ongoing joke has been sending him 330i coupes on Craigslist. “You know you can get this drivetrain already in a BMW.”

[Habla]

Well I decided it was time to join the fun and get serious with my slicktop project. Step 1: take out the trash:




I bought a parts car, an e91 328xi/6mt




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Well damn, that one is too nice and makes a great babymobile. Ok, buy another 6spd e9x! A smashy 330i.
It also came with bonus interior goodies for the new touring, like heated sport seats and not-ugly wood!





I'm really enjoying the progress in here!
-Peter

[hubcapboy]

While I'm thinking about it and because there's no better place to put it (although I'm sure I've rambled about this... it only became relevant right now)

There are two kinds of N52 oil pan bolts. The one on the left is for the aluminum (thick flange) automatic pan. The one on the right is for the steel (thin flange) manual pan. The bolts are identical length, but the steel pan bolt has a captive spacer so the bolt "behaves" the same way when tensioned. The challenge here is that the auto pan "kit" has some longer bolts for... whatever the auto pan looks like.

To get enough of the no-spacer bolts, we ended up buying two auto kits each.

The reason this is important? If you order bolts for a manual transmission because you have a manual transmission, you’ll probably pull the threads out of the bottom of the block because your bolts won’t have enough embedment.

[hoveringuy]

This is hopefully the last post from me on the belt tensioners.

One niggling issue I had when I installed the N54 tensioner is that the belt doesn't appear centered on the pulley, there's a solid 7mm space between the belt and the end of the pulley that makes it look like the belt isn't centered, and that made me concerned that there was a difference in backspacing between the N54 and the X5 tensioners.



So, I did the rational thing and ordered a genuine X5 tensioner, P/N 11-28-7-565-225. The only differences between the N54 tensioner, P/N 11-28-7-563-927 and the X5 one is that the former comes with a steel bolt and the latter an aluminum bolt. Also, it seems that all instances of N52 tensioners have silver tension springs instead of black. Different steel composition or just paint... I dunno. Otherwise, everything else between them was identical.

E70 X5 on the left and N54 on the right



I also discovered why my belt looked so cattywampus on the N54 tensioner: the pulley is physically thicker. The N54-style tensioner has a 30mm thick pulley whereas the normal N52 one is only 26mm AND any N54 or N52 with that style tensioner has a 7 rib K07 belt instead of a 6 rib K06 belt!

I tried mounting a set of 26mm pulleys on the N54 tensioner but that legitimately screws things up because it changes the pulley centerline.

Notice that the backs of the pulleys are perfectly aligned.



Bottom line.

The N54-style tensioner works just fine. You can either order the cheaper N54 tensioner ($65) and then order the aluminum M11x99 bolt that goes with it separately ($15) or just order the X5 tensioner for around $140.

Sorted.

[Caperix]

The water pump is not anywhere near the tensioner, and it's not connected to the belt either, not sure how it's related if true. But that would be interesting to know, although the N54 pump is plastic and known to crack, so probably not an upgrade though.

Sorry about that, I was not very clear. The larger water pump installs below the compressor so I was thinking that was the reason for moving it, though looking into it deeper, an adapter plate is installed on the pump not the compressor as I had thought. This will not effect using the tensioner for a/c delete but it does mean that the compressor length difference is in the pulley not moving the compressor, so the v12 compressor will still be the best route for and.
While it must flow more I agree that the n54/55 pump would not be a good upgrade due to the common leaks between the plastic & metal parts of the housing, or worse through the connector that can short the dme.

[hoveringuy]

The water pump is not anywhere near the tensioner, and it's not connected to the belt either, not sure how it's related if true. But that would be interesting to know, although the N54 pump is plastic and known to crack, so probably not an upgrade though.

I think the X5 4 zone climate feature has an additional mixing valve that sits behind the AC compressor; compressor needed to be pushed forward to make room.
SInce it no longer aligned with the serpentine they gave it its own belt and used N54 style tensioner for the main belt.
The remaining mystery for me is why N54 and X5 tensioners have different PNs.
I'll have that answer soon.

[hubcapboy]

Caperix was trying to tell us about the 2-belt setup somewhere around page 18 when I was looking at different AC compressors.

I didn’t look into it further because I didn’t want to add a second pulley to the crank, and from what I could tell the m54 compressor would align the pulley with the inner belt (and have the wrong number of grooves) and wouldn’t stick out far enough to catch the outer belt.

We didn’t realize at the time that it would solve the AC delete issue.

[nando]

They use the n54 water pump so that may be what the extra clearance is for. If there is clearance for the 2 row pulley I think a m54 compressor should bolt up for AC swaps as well.

The water pump is not anywhere near the tensioner, and it's not connected to the belt either, not sure how it's related if true. But that would be interesting to know, although the N54 pump is plastic and known to crack, so probably not an upgrade though.

[hubcapboy]

This is the best you can hope for from cleaning up a magnesium valve cover. If this looks like hell after 6 months I can clean up the other one and paint it.

It looks REALLY cool and dark blue when it’s wet, but dries to grey. I can’t find a single reliable resource for a good finish that keeps that dark blue color that doesn’t sound like a commercial process.

[Caperix]

They use the n54 water pump so that may be what the extra clearance is for. If there is clearance for the 2 row pulley I think a m54 compressor should bolt up for AC swaps as well.