cfwthb_94

I'm having oil come out the top of the oil drain line. Where the flange is at the turbo. I'm wondering if the line isn't big enough and it's flowing back up the tube from the oil pan back into the turbo. Is that possible and what is the recommended size for the line?

96 GSR-T

According to what I know about gravity, if your return/return flange is higher than the bung on the oil pan (and if that is also high enough) oil should not travel back up the line. Make sure the line has fall all the way from the turbo to the pan, if you have that there should be no issues.

Pretty sure the return size should be -10 or larger.

Pics are worth a thousand words......

TheShodan

iTrader: (14)

It's not just the size of the line that is important (-10AN is recommended for both T3/T04E/S and Borg-warner series), while -8AN and -10AN are normal for GT "R" series. but there are 2 additional areas that you must check as well. As the person above posted, make sure that the line is slightly down angle, as it is gravity fed.

1) Make sure there are NO 90 degree AN fittings or kinks in the return line. This is important, as it will cause a backup into the CHRA.

2) Obviously , blockage in the line could be a problem. Some return lines that have been used over and over again in different setups have their rubber degrade inside the line itself (this rarely happens to Earls, but, if you got a cheap return line or one that is old, the degrading could cause a blockage in the line like a corraded artery from the bad cholestoral of a 60 year old drinker whose eaten only cheese burgers for the last 20 years.

3) People tend to pay too much attention to the line that goes to the return flange itself, but forget about the opening from the drain of the CHRA itself through the drain flange gasket to the flange. A) You must first make sure that the oil drain flange gasket is not obscuring the opening to the return flange itself. Sometimes it is because the actual opening of the return flange gasket is a couple of millimeters smaller than it needs to be, and the return flange gasket could cause a backup. B) Check to make sure that the inner diameter is about .50" to .59" ID (Inner Diameter). For Holsets, they need to be about .59" for the oil drain flange. The Garrett & Borg-Warners use the same ID of about .50" to .59"

So, check your return flange. Hopefully, you didn't get a cheapo return flange for the turbo that you have (though you didn't list the manufacturer), but that should help you with a few of your issues.

cfwthb_94

Thanks for all the input, very helpful. It's a borgwarner t3/t4 turbo. Inline pro manifold, with plenty of angle for the drain.

This set up was previously on a ls motor that had no problems what so ever. Now it's on a gsr/b16 setup with a different pan than before. I never took the flange off of the turbo just disconnected it from the pan when taking it off of the ls motor. Had a fitting welded to the gsr pan and put a 45deg. fitting on that. It started to leak then a little. Now with a 3rd setup...lol...it's leaking a lot. This time around I put a new gasket on the flange to the turbo, tighened it down pretty good. Previously there were two different size fitting openings. I thought this might be the cause, which is why i put a new fitting on the turbo side, the same size as the oil pan side now and new hose, coolant hose, one that fit properly. And it still does it. The new fitting opening's are smaller than what they were on Ls motor that had no problems which is why I was wondering if this new one might be too small.


I'll get pics in a little while to put up.

cfwthb_94

it was a little defficult to get these pics.

SIXTY-1HATCH

I would say use -10 braided line and an fittings. Whatever will work, but looks like you just need to turn the fitting on the pan more upward toward the flange. Do that and pull those crappy fittings off, and re-install with some silicone, or copper gasket maker on the threads. Thats all that is, crappy seal with those threads, put alittle on the threads and put em back on you'll be fine. Just turn that pan fitting more upward, you want to avoid a flat or upward into the pan like that. Just give it alittle more up and your fine, other than re-sealing those threads....

TheShodan

iTrader: (14)

Also, whatever turbo return flange gastket that is, remove it, and get a fresh one. that looks caked up.
The T3/T4 Borg-warner turbos use the same size fitting and flanges as the Garrett.

cfwthb_94

that's a brand new gasket. it's only been on there for like a week. I'm going to mess around with it tomarrow and try to get some -10 and ss lines.

And TheShodan, I have a question. I have yet to find out why through my reading on this site, but what is the difference in divided housing and "twin scroll"? Figured I would ask while I have your attention on here.

Tjabo

Is this true up to a certain size, or is it just something you have to avoid altogether?

Tjabo

TheShodan, I'm currently rebuilding my drain, trying to adhere to your specs, but man, it's a challenge!

First of all, I have two different drain flanges that appear to be nice quality machined aluminum pieces, but neither one is easily setup to be even 1/2 I.D. One is setup with a male -10 on it, so I guess I could bore that one out to the spec you mentioned, I'll have to check on it. The other one is setup with a 1/2" NPT female thread. If you use a brass 1/2" NPT male to 5/8" barb fitting, that one gives you an I.D. of about .450" also.

I guess in the morning I'll go hunting for a 1/2" NPT male to 3/4" barb fitting. Then I could upgrade my hose to some 3/4", and all I have to do is figure out the bottom. Right now I'm actually contemplating using 45 degree copper fittings to a copper 1/2" NPT male into the hole I tapped into my oil pan. That would be pretty much the mother of all oil drains if I used 3/4" copper pipe. . . Especially if I upped the tapped hole size to something even bigger than 1/2" NPT.

I *REALLY* want to be able to keep my -4 feed line with no restrictor, and not burn oil at idle. . . Got any thoughts to share about this?

Thanks!

TheShodan

iTrader: (14)

There's not much more I can add here. Really just to say that you're the only person that is going through this kind of return flange problem on the older T3/T4 Borg-warners. You really don't want to use a -4AN unless you have one of the S-Series units. But the 1/2 OD was the better choice to use. Some manifolds make it very difficult to get the right angle return flange. avoid the 90 degree AN fittings altogether

Tjabo

I'm currently running an SC6265sp. Precision told me I needed to run a -4 feed line, and I *thought* you were saying that was the right thing to do to. . . . Seems that in addition to buying the wrong flanges, I need to go back and re-read! LOL. . .

Is there a good flange brand that makes it easy to get a drain I.D. in excess of .5"?

Thanks again!

cfwthb_94

this was a long time ago but I found my problem. It was a cracked oil drain flange. I have a whole new turbo setup now. 6265s t4 .68a/r ex. afi topmount.