M30 OEM Turbo project

[Galicianslash]

SUB'D! Love the M102 and M106 motors! Great work!

[CorvallisBMW]

Thank you!

[george graves]

Looks great! Can't wait to see more. And yes, something about sand blasting parts will kind "open up the pours" of the mental, and really let some rust develop in week or so.

As far as the BBQ paint, I've yet to find any paint that will hold up to NA exhaust temps for more then a few months. If someone had a better solution, let me know.

[CorvallisBMW]

Looks great! Can't wait to see more. And yes, something about sand blasting parts will kind "open up the pours" of the mental, and really let some rust develop in week or so.

As far as the BBQ paint, I've yet to find any paint that will hold up to NA exhaust temps for more then a few months. If someone had a better solution, let me know.

Ya I'm sure they will start to rust a bit, especially in this moist PNW winter air. But all the pieces that aren't painted at this point are going out for ceramic coating, so I'll let them deal with it.

I'll report back on how the paint holds up after a few months of running. My guess is that the turbo will be fine, as the center section really doesn't reach "exhaust" temperatures. I mostly wanted to prevent further corrosion, as some of the pitting is already kind of nasty.

[TimeMachinE30]

Looks great! Can't wait to see more. And yes, something about sand blasting parts will kind "open up the pours" of the mental, and really let some rust develop in week or so.

As far as the BBQ paint, I've yet to find any paint that will hold up to NA exhaust temps for more then a few months. If someone had a better solution, let me know.

Just read an interesting piece about painting iron.. that is to heat it after cleaning.. it is very porour and holds water. Flash the water from the metal.. then paint.

Otherwise, once painted and heated to operating temps, the water trapped will release taking your paint with it.

[nomansland92]

This is a awesome build can't wait to see more

[CorvallisBMW]

Just read an interesting piece about painting iron.. that is to heat it after cleaning.. it is very porour and holds water. Flash the water from the metal.. then paint.

Otherwise, once painted and heated to operating temps, the water trapped will release taking your paint with it.

That's a good point, I hadn't thought of that. I hope that between sandblasting and washing with alcohol I have driven off all the water, but next time I'm painting cast iron I will definitely give that a shot.

[CorvallisBMW]

Time to put the turbo back together!

First step was to get a bottle of good assembly lube in order to prevent a dry start. The last thing I want to do is damage those new bearings!




Insert 1 bearing in to each side, followed by a new snap ring. First side:






Second side:






Now at this point things start to get a little more complicated. All the pieces have to be assembled in a very particular order and orientation, or many bad things will happen once the turbo hits 100k rpm. This exploded view diagram I found on the Pelican Parts forums helped immensely. Apparently these same K27 turbos are OEM on many same-era Porsche models.




Next part is the flat washer, #3 in the diagram, immediately followed by the thrust bearing #4. It's very important that the side of the thrust bearing with the oil galleys faces DOWN during the installation, or oil starvation will occur (the offset guide pins help prevent this)



Here's an idea of how the old and new thurst bearings look next to each other. The old one was very worn and some of the galleys were filed with charred carbon, meaning very little (if any) oil was flowing through them.



Don't forget the lube!




Next up was the oil splash guard, spacer and mating ring (#5, 6 and 7)




Once all those parts were installed, I was left with this strange bushing with an integral ring. It wasn't on the diagram, and I didn't remember where exactly it belonged. But once I placed the seal plate on the bearing housing, it became obvious.






Getting closer! Next step is to replace the turbine seals near the exducer. The new seals had a much larger gap than the old ones, which concerned me a bit. But some internet research said that this is how they're supposed to be, so on the shaft they went. (even though the diagram shows 4 in total; 2 on the compressor side and 2 on the turbine side, the BMW K27 only has 2 on the turbine side)




Now time to install the turbine shaft, heat shield and compressor wheel. I was lucky, the shaft slid right in with no resistance at all :giggle:




Now time to install the compressor housing, being sure to align the marks I made before I took it all apart (knowing I was going to be sandblasting and painting most of the parts, I elected to etch the marks with my dremel as opposed to marking them with a pen)




New housing bolts installed with plenty of anti-sieze




Now the exhaust housing, again with anti-seize




And voila! All done... sort of. Once I mock up the whole system, I'll be taking the turbine housing, exhaust manifold, wastegate manifold and downpipes in for ceramic coating. So for now the housing is bare, but that doesn't affect fitment.

[ThatOneEuroE30]

What's the size on that turbo

[CorvallisBMW]

I have no idea, it's a K27 from the factory 745i. That's all I know.

[CorvallisBMW]

If my order of studs from McMaster arrives today, I should be able to do some test fitting tonight. Woohoo! I'm stoked as to get this stuff mocked up and start putting all the piping together, but a bit nervous about (possibly) having to bash the strut tower to make the wastegate fit :???:

Also, I was wandering through Home Depot the other day and spotted these things in the plumbing/irrigation section. They're not exactly designed for automotive use, but could they be used for charge pipe connections? They look slick, come in tons of sizes, and aren't bright neon blue or whatever color those ricey silicone couplers are.

http://www.homedepot.com/p/Fernco-3-in-x-3-in-PVC-DWV-Mechanical-Flexible-Coupling-P1056-33/100372296

[TimeMachinE30]

The turbine looks bunged up, a chip on one edge. Is that a concern? Effect on balance?

Good work.

[CorvallisBMW]

The turbine looks bunged up, a chip on one edge. Is that a concern? Effect on balance?

Good work.

Yes there is the tiniest ding on one corner, but I doubt it will affect the balance any.

[ThatOneEuroE30]

It shouldn't and if you really wanted to you could probably straighten it back out.

[CorvallisBMW]

My order from McMaster finally came in, so I'm able to get the manifold mounted now.

One if the interesting differences between the standard m30 motors and the turbo m102 or m106 motors is the difference in exhaust stud diameter. I didn't realize this until I pulled my old manifolds off and saw the studs were M8, while the new turbo studs are M10. This left me with just 2 real options; drill out and tap the head to the larger M10 size (tricky while it's still in the car) or purchase long M8 studs and sleeve them. After seeing what JoeMadoo did here: http://www.r3vlimited.com/board/show...=341531&page=2 I decided to go with the latter route.

After some searching I was able to find the needed parts on McMaster




You can clearly see the difference in diameter between the M8 studs and the M10 studs. I am a little concerned about the strength of the thinner M8 hardware because obviously there is a good reason why BMW chose to upgrade to M10. So I'll be keeping a very close eye on everything.




I measured the depth of the manifold, exactly 70mm




And cut some of the copper tubing to length. Perfect fit.




Knowing that threading in studs is a PITA, I also chased all the threads on the head to make it an easier job. It made a big difference in the mount of effort required to get them to seat properly (looks like I also should replace my VCG).




Installation was a bitch, because the studs stick out too far to allow the manifold to slide over after they've already been installed. The only way to get it all on is to hold the manifold in place with one hand (not much fun, it's about 40lbs) and try to thread in the stud with the other, all while not allowing the copper tube to slide off. After much wrestling and grunting, I got a few studs in place. This is at least enough to begin mocking up my plumbing.



It quickly became apparent that my A/C line is going to be trouble. Even when I disconnect the closest hard bracket on the shock tower and pull it away, it still rubs on the manifold. It would only be a matter of days before the vibration of the engine wore straight through the insulation and caused a leak, so I'm going to have to find a solution for this. If I could loosen the nut on the compressor, I might be able to rotate the hard neck and gain some clearance. But doing this would also mean leaking freon (it's original R12) and I want to avoid that. I may end up having to go to an A/C shop and have a line custom built.






Now time to put on the wasga.... shit. Obviously this thing isn't going to slide over those studs, so I'll have to pull the manifold, install it, and then try re-installing the hole thing as one piece. Hooray for difficulty! You can also see how little space there is between the shock tower/frame rail and the manifold. I've heard conflicting info on whether it's necessary to clearance this area or not... can anyone chime in with experience?