Oil drain for relocated turbo?


  • Oil drain for relocated turbo?

    For guys running relocated turbos - what did you do about oil drains, and did it work?

    I put a ball bearing turbo with a .035" restrictor, as Garrett recommends, in the usual A/C compressor spot, clocked it within 15 degrees of vertical, and I even punched a new 1/2" oil drain in my NA pan pretty much straight down from the turbo, so the drain was about a 65 degree downward angle overall. 4000 miles later I have oil (like, LOTS of oil, enough to pool in the compressor housing) on my compressor side and hilariously large blasts of white oil smoke out the exhaust on the occasional stop, but the turbo still pulls great, makes no new noise, etc - looks like my seals are gone, exactly how they would if I had insufficient drainage. The oil is definitely coming from the turbo, tested this venting the valve covers to atmosphere instead of catch can => post-MAF/pre-turbo. The drain is clear when cold, I checked it, and it's above the oil line in the pan, checked that too.

    The only thing I can think of is that the drain run is too long (think it's about 19" from drain to fitting) for 1/2", and I should just pull the pan off and shove a giant fuckoff 1" fitting on there. Was *really* hoping to not have to find a place to pull the motor this winter.

    Anybody else have a similar issue? How big are people making their oil drains? Are you just using the drain in the turbo pan and calling it a day?

    (one thing - I was daily driving the car like 200-250 miles a week, so it probably was getting more normal wear and tear than a lot of other relocated turbo builds…?)

  • #2
    as far as I remember, stock, and most turbo's I have dealt with run 3/4" drians. Im kind of surprised you ran 1/2.
    Damn dirty angels....these cars!

    Current Daily Driver - 86 Turbo.
    Under the cover - THE BANANA… that needs to be re-energized.
    sigpic

  • #3
    Allegedly with the restrictor 1/2" is enough, but yeah, guess not! There's a mistake I'm not gonna make again.

    Stock drain is 5/8" and is blocked by the dipstick, but it must work…

  • #4
    I'm running a 1/2" npt to 10an drain on the pan followed by 10an hose. Haven't had any issues. If its draining straight down then I would thing you may have positive pressure in the crank case
    Usual Z31 suspect: Garage Queen (aka broken)

  • #5
    Hmm. That's possible, I guess. But I was venting the valve covers to atmosphere for a while, then switched to a catch can with the outlet going to the charge pipe post-maf pre-turbo. By the time I did this I was already burning oil, so right now I just have the can going to atmosphere because I wanted to make absolutely sure that the oil on the compressor side was coming from the turbo. That *should* take care of it…?

  • #6
    I had many many issues with my subaru blowing oil into the intake. From there on out I will never route back into the intake from the valve covers.

    Oh, and i totally ordered a -10an to weld onto the oil pan after reading this conversation lol
    Usual Z31 suspect: Garage Queen (aka broken)

  • #7
    Did you make sure to put your drain at about the stock drain height?if you are lower than the oil level you may be having oil back up in the return

  • #8
    ^^ this, big time, would be major issue.
    Damn dirty angels....these cars!

    Current Daily Driver - 86 Turbo.
    Under the cover - THE BANANA… that needs to be re-energized.
    sigpic

  • #9
    necromancy! 300zxturboftw called it, btw. Excess crankcase pressure. Motor was clearly too tired to be a daily driven NA2T, lol. It had 160-170 all round before I did the NA2T but 4K miles later I had 120 on 11, 90 on 3, and 120 on 4. Got a VG33 rebuild about to go back in.