turbo oil drain

-
70wayfarer

70wayfarer

Well-Known Member
Joined
Jul 20, 2011
Messages
419
Reaction score
33
Location
new zealand
hi all....
just wanting to know what size the oil drain back should be on a s475.I have a 1/2" drain back to the timing cover where the fuel pump used to be.

got my car up and running and been on shortish road trips to get afr's sorted. have noticed on start up and idle some signs of white smoke out the exhaust. today I found oil dripping on the chassis rail under the turbo. had a look up underneath the car and could see oil dripping at idle from around the v-band where the cartridge and hot side housing mate up.
did not smoke at all at first and now getting worse. turbo is new outa the box.
could this be because the oil is not getting away fast enough.

thanks guys
 
My oil recently started doing this. The oil drain line was not dumping it fast enough. I pulled the drain line and blew into it with an air tip and then put it back on. It stopped. The oil coming out of the bearings is kind of weird and frothy looking and doesn't flow well, so if the drain line is not 45 or more downward degrees, it gets backed up. Mine was the result of the angle changing to a horizontal before it hit the pan. Even one inch seemed to block it up. Mine's a 10an so it's fairly large too.
 
hmmm...so it is not uncommon then. my drain has not very much fall at all going from bottom of turbo to side of timing cover as you could imagine. thought -4 feed and -8 drain would have been sufficient. obviously not. going to pull motor and box to check a few things, so will put a fitting in the pan and up size drain to -10.
 

Attachments

  • P1010661.jpg
    58.2 KB · Views: 191
  • P1010663.jpg
    39.9 KB · Views: 187
  • P1010664.jpg
    37 KB · Views: 187
  • P1010665.jpg
    33.2 KB · Views: 191
You might have to put a restrictor in the oil feed line. 4an feed is a lot of oil. They sell a 4 an fitting with a .080 EMD hole in it. It sounds like you are drenching the Turbo with too much oil in addition to it not draining properly.
 
I think the ideal setup would be having the fitting enter the oil pan at a high angle welded to the pan, or if you're using the timing cover, if there's a way to shorten the travel from oil outlet to the cover, and steepen the angle as much as possible, that would do it. Is the core of the turbo also clocked so the oil drain is at the lowest point of the turbo?

This is where mine likes to leak but barely any:

 
Mad Dart said:
You might have to put a restrictor in the oil feed line. 4an feed is a lot of oil. They sell a 4 an fitting with a .080 EMD hole in it. It sounds like you are drenching the Turbo with too much oil in addition to it not draining properly.
Click to expand...

-4 4 is what I was told to use. I did think it was on the large side considering the oil line on my Vortech was smaller.
will look into a restrictor of some sort, and a larger drain to the pan. my drain has very little fall. the cartridge is clocked at 22* as per Borg Warners recommendation.
what if any damage would have resulted from this.
I've only just started to give her some boost and this seems to be when the oil leak started. higher rpm more oil into the cartridge that can't get away.

cheers
 
fwiw. im running brake line for the feed to my turbo and a 1/2" return. havent had any problems yet. the h1c im running has a built in restrictor.
 
Serj22 said:
i didnt know you didnt have a restrictor. Thatll be the first thing you want to do.
Click to expand...

this is my first go at a turbo so still learning. the vortech oil line was not much smaller but connected to a restrictor nozzle that was directed at the gears.
Mad Dart suggested a .080" restrictor. i'm thinking Holley jets.
 
70wayfarer said:
this is my first go at a turbo so still learning. the vortech oil line was not much smaller but connected to a restrictor nozzle that was directed at the gears.
Mad Dart suggested a .080" restrictor. i'm thinking Holley jets.
Click to expand...

Type "Turbo Oil Restrictor " in an ebay search. It will give you some ideas on how to home brew a good one.

I have used drilled out Allen set screws in an fittings before to restrict fuel. It is cheap and works very well.
 
One old school mod guy i talked to before I did my turbo setup told me about how people used to put a brass T valve or ball valve inline, and then just open it barely.

Or on ebay they sell an AN adapted restrictor. That's what I have - it just a very tiny hole in the mounting plate.
 
ok...went out to the shed earlier and had a think about the holley jets as a restrictor and this is what I came up with.
found that the adjuster end of a holley needle valve is same thread as the jets.
I drilled the AN -4 fitting I had with 8.5mm drill bit about 8mm deep and tapped it with 1/8" NPT tap. this with a bit of locktite will secure the cut down valve very well. now I have a huge range of choice for oil restriction.
 

Attachments

  • P1010666.jpg
    42.7 KB · Views: 145
  • P1010667.jpg
    43.2 KB · Views: 138
  • P1010668.jpg
    36.3 KB · Views: 137
RustyPlymouth said:
the only problems with the restrictors is, if you go to small you wont know until its to late.
Click to expand...

that is soooo true.
i'm not going to use one at this stage. got the option to if I do. going to run a -10 drain straight down to the pan and fit valve cover evacuators to eliminate crankcase pressure. having only -8 drain and no pcv only breathers I think was part of the leak situation. I think?
 
mine is dry with two breathers on my valve cover. no pcv. turbo is dry but the valve cover gets a nice coating after a few hard pulls.

you could use a restrictor but start big and work your way small until it stops leaking. then decide if its still getting sufficient flow.

as for the seal. there isnt any kind of rubber seal on the hot side. there is what is referred to as a piston ring that rides on the shaft. not sure if you are up to the task of taking your turbo apart but you could probably get away with cleaning out the ring land. my understanding is that when they fail its because the ring land is dirty with coke and starts to spin the ring. when i rebuilt my h1c the only real problem i found with it was the dirty ring land. there was evidence of it leaking oil when i got it and there was a slight hitch when spun by hand. also wouldnt spin long when spun by hand. after cleaning it really well and replacing the piston rings it spins really nice (spins for 10-20 seconds after i shut it off) and is really smooth. spins for a couple seconds when spun by hand now as well. there are videos on youtube for rebuilding turbos. there are a lot. may be able to find a video for your specific turbo. sounded like yours was new though. might be worth calling the manufacturer and letting them know what is happening.
 
thanks for the input guys..........stripping the turbo down is no big deal. will do that and give the ring area a good clean sending back to point of purchase in the US from New Zealand is not an option, time wise and cost wise.
 
Garrett says .040 and 45 psi at highest engine RPM. IIRC Holset recommends 2 lpm. Its in a Holset rebuild pdf.

"...The minimum oil pressure when the engine is on load must be 210 kPa (30 lbf/in2
). Maximum
permissible operating pressure is 500 kPa (72 lbf/in2
) although 600 kPa (88 lbf/in2
) is permitted during
cold start up. Under idling conditions pressure should not fall below 70 kPa (10 lbf/in2
).
15. Recommended oil flows for the turbochargers are 2 litre/min at idle and 3 litre/min above maximum
torque speed..."
 
the literature that came with the turbo had no flow figures, only that it got plenty of oil and drain was of sufficient size.
my oil psi is all good
 
You must log in or register to reply here.
-

Back
Top