TBI Oil Drain Question

[Buckracer]

Ok got my TBI header on and man it is TIGHT. Classic SV clearance. Anyways, on my 88 lebaron, the oil drain sits about level with or below the oil pan flange and the drive shaft is right in the way. would it be alright to run the AN-10 line I'm using under the driveshaft, and put it into the pan below the oil level line? I believe this is supposed to be a gravity feed line if I remember right but will my way work?

My thinking is that the oil is being pumped into the turbo and therefore pushed out. I think the oil pressure should be enough to push the old oil back into the oil sitting in the bottom of the oil pan. My only other option is to put the line OVER the Driveshaft, but then the oil will have to be pushed uphill and I think the other way would work better in terms of less resistance.

There are ZERO pics of peoples fabbed up oil drains, just the pics of the tube sticking out of their pan- no completed pics.

[puppet]

I remember a guy or two bringing that line around to the front of the pan. You might need to fab up a fitting for the discharge on the turbo so you're as high as possible to start with.

Going below the oil line won't work. Fluid seeks it's own level and that would be someplace in the line ... ie, no drainage.

[Buckracer]

Totally agree- But if the oil is pumped IN in the turbo, shouldn't there be a force pushing the oil out the other side? and is that force great enough to push the oil back into the pan through existing oil? sure when just sitting the line may have oil sitting in it, but on start up wouldn't it just start moving again once the pressure comes up? or maybe I'm misunderstanding how the oiling system of the turbo works?

I'll look at it again in the morning and when its set I am gonna post pics to try and get more info on this up since so many people ask about it and the headers on the market when said and done are like $600

[turbospirit]

Quote:

Originally Posted by Buckracer Totally agree- But if the oil is pumped IN in the turbo, shouldn't there be a force pushing the oil out the other side? and is that force great enough to push the oil back into the pan through existing oil? sure when just sitting the line may have oil sitting in it, but on start up wouldn't it just start moving again once the pressure comes up? or maybe I'm misunderstanding how the oiling system of the turbo works? I'll look at it again in the morning and when its set I am gonna post pics to try and get more info on this up since so many people ask about it and the headers on the market when said and done are like $600

Oil is pressure feed in, but gravity drains out. If the oil drain is below the oil level at all, the oil will take the easiest way out, which is the seals on the turbo.

[Buckracer]

That is what everyone says, but how? the oil is pushed in so where does the pressure go? imagine blowing into a straw full of liquid and nothing coming out the end. how does that work?

Anyways, I'm gonna end up running a 90 off the turbo but with the tilt of everything wont it pool right in that bent too??? Sheesh...

[detobias]

Quote:

Originally Posted by Buckracer would it be alright to run the AN-10 line I'm using under the driveshaft, and put it into the pan below the oil level line? I believe this is supposed to be a gravity feed line if I remember right but will my way work? My thinking is that the oil is being pumped into the turbo and therefore pushed out. I think the oil pressure should be enough to push the old oil back into the oil sitting in the bottom of the oil pan. My only other option is to put the line OVER the Driveshaft, but then the oil will have to be pushed uphill and I think the other way would work better in terms of less resistance.

1. Ideally "zero backpressure" oil return line, like factory = straight down
2. Less Ideal- some 'back pressure' cuz theres some AN plumbing, elbows...

yer right, the pressurized oil will overcome the added resistance

I would suggest the 'up&over' ; actually the oil in the 'up&over' part should act as a siphon, requiring almost 0 pump force..
also it would hold some oil (above the turbo) after shutdown, perhaps post-lubing/cooling the turbo some?

going into the pan below the oil level would also work ;
the oil level would climb your return tube to the same height as it is in the pan..
LOL if U made that section clear it would be a 'oil level sight tube'

[puppet]

Quote:

Originally Posted by Buckracer That is what everyone says, but how? the oil is pushed in so where does the pressure go? imagine blowing into a straw full of liquid and nothing coming out the end. how does that work? Anyways, I'm gonna end up running a 90 off the turbo but with the tilt of everything wont it pool right in that bent too??? Sheesh...

The turbos center section isn't entirely under pressure. The oil is restricted at the opening to the bearing house and the bearings provide another restriction ... but part of that section sees atmospheric pressure too. (Just like the rods and mains in the pan itself. If that oil couldn't shed off the crank the bearings would be swamped.) If that happens in the turbo, the oil would/must seep past one of the seals.

[Buckracer]

*CLicK*

OHHHHHH ok Good explanation puppet that makes perfect sense!

i'll run it up and over. we'll see and i will be sure to post up my pics of it allll fabbed up

[Buckracer]

to update this, I ran it up and over. I used a 45deg 10AN and a short length of hose with the braiding stripped off one end to a 90deg push lock 10 AN bolted into a flange I put on the pan. its pretty easy to see the oil level on the inside of the oil pan so that wasn't hard.

I have pics and am going to post them- hopefully in a TBI-DIY with some finished pics. I didn't take em all the way thru.....Grrrr.

[The Pope]

BTW, when you run up and over the oil pools in the line and must be pushed towards the engine, even hard while acelerating.

As for the oil return. Yes the turbo needs to be above the oil line, the line doesn't. Many turbo kits out there, expensive ones even return the to oil drain plug. The oil in the pan also isn't just sitting there either. Your returning the oil right where the vac is from the oil pump and there is a convection vac pulling oil where the drain plug sits.

Then our turbo cars have horrid oil control and windage, really nice for our lifters and bearings. Our stock oil return adds the oil right on the crank where it can wrap up and fill with air. After a hard drag strip run a low oil return could suck a little oil out the exhaust past the ring. But that is the only real down side, for the most part were talking about an old wives tale that many haven't tried lol. So sure, maybe there is a small issue with oil returning. But the engine without a doubt has a bad oil issue from turbo oil windage. Remember not to assume our return is where it is because it should be there, that was the easiest location lol.

[Buckracer]

I'll keep it in mind and the line i fabbed keeps a level or downward angle. Thats what I was thinking, if you ran it to the bottom of the pan you get a little suction, but following the wives tales and ghost stories I put it right at the top of the pan. I have pics but id say the biggest problem I had was blocking off the old oil drain. GOD I should have done that when the head was off. probably cut an inch o two off, and plugged it. now I was stuck ghetto plugging it....