Turbo drainback

clay · Posted: Tue Jul 27, 2010 5:21 pm Post subject: Turbo drainback

My family get together for my mother in law's 70th birthday is over and now I can get back on trying to get my pile back together. Previously I had the turbo drainbacks going into the fuel pump location. Main reason I did this is that it was about the only thing I could do with the engine in the car. Now I would like to run them into the oil pan. Preferably I would like to use a bulkhead fitting instead of welding a fitting on. My question is I know that normally it is desirable to have the return above the normal oil level. However in the Moroso pan I have with the built in windage screen, there isn't really anywhere for a nut to go for the bulkhead fitting. I can easily go into the sump and it would be a really good straight shot to do that. It would be below oil level of course, but I can't see where that matters. Gravity will still allow the oil to drain in to the sump. Sure some oil will remain in the line, but so what? What am I missing? Currently I have a line that is 1/2" o.d. tubing with some short sections of 1/2" hose and have no problems. I am planning on moving up to something like a 5/8" tube with some short sections of hose once I get away from all the heat. What are everybodies thought on draining into the sump? Clay

af2 · Posted: Tue Jul 27, 2010 8:35 pm Post subject:

I would put it on the left side above the sump. That will scavenge the oil from the Turbo instead of a dead head drain back.

10sec.et · Posted: Tue Jul 27, 2010 11:48 pm Post subject:

what the hell happened to my post ???? Confused

anyway, you need a wide open free flowing drain. it will back up into the turbo and leak into the exhaust.

clay · Posted: Wed Jul 28, 2010 4:02 am Post subject:

clay · Posted: Wed Jul 28, 2010 2:15 pm Post subject:

I think I have it. My analogy would work, however it isn't exactly what is happening. The top of the system isn't open like my example above. Now a closer analogy is a tank with a pipe leaving the bottom. It won't drain very well unless there is a vent somewhere. I think the air pocket that is between the turbo and the sump has nowhere to go and won't let the oil drain back smoothly. This is my plan to try. The first probably 6 - 8 inches will be hard line of some sort to get by the exhaust manifold, then I can go to some sort of flex line to the pan. I'm thinking of putting in a small nipple with a vent on this upper hard line section and running it to either a breather or just to the valve cover to let the drainback vent. Now what does everybody think?

af2 · Posted: Wed Jul 28, 2010 6:08 pm Post subject:

If you have room:

Plumb both turbo's to a tank with a breather on top and a big hose to the left side pan above the sump?

My thinking is to have the windage help the drain back.

10sec.et · Posted: Thu Jul 29, 2010 12:01 am Post subject:

my missing post:

we had a TT Mustang a while back that would not stop smoking. it looked like a mosquito fogger going down the road. the drains from the turbo had 1/2" line and had a slight "dip" in both. we re-routed the drains and got the right bank to quit smoking but still had some smoke from the left. we then went to 5/8 line and re-routed it again....... no more smoke. i dont know what turbos this car had but it was explained to me that if the oil backs up into the turbo, the seal cant keep the oil in if its under pressure from the oil so it pukes out of the exhaust. i have also seen this occur with an incorrect PCV system. we had a Challenger that literally left trails of oil into the shop after a test drive.

clay · Posted: Thu Jul 29, 2010 4:02 am Post subject:

TSHACK · Posted: Sun Aug 01, 2010 10:40 pm Post subject:

Also if that oil is allowed to back up too long it will start coking the shaft up. Causing the turbo to slow down & heat up more, Making the problem worst. I've seen it on an improperly installed drain back line, On an aircraft. it was brought in as down on power & very high egt.

robins44 · Member Joined: 29 Dec 2007 Posts: 578 16889.38 points

what turbo(s) are you running, i rebuild turbos all day everyday.

clay · Posted: Thu Aug 05, 2010 2:03 am Post subject:

Right now in the learning phase I'm running a Chinese knock off of what I can best guess is a Turbonetics unit. If I can keep it together long enough (think I can now - learned a lot - although the hard way) I'll get some data and see where I need to go from here. Clay