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V1 Drilling above oil pan for 2.2 Turbo Drain port

SwerveMonkey

Well-Known Member
SwerveMonkey
I've been heavily leaning on and learning from Bar-Air's posts back in the day when he turbocharged a 2.4 ecotec....

I was trying to confirm on my own but have only gotten so far with google and forum searches ( here and elsewhere )

but i really want to ask as confirmation before i do something potentially stupid...
Is it really just that simple to drill a hole out in the engine block for the turbo oil return line to go into??
like in the image here at back of the engine, red circle above the oil pan...

plYCeM4Xj


I'm seeing that the Z54 I bought from another forum member here is by default compatible only with the LNF/LHU turbo charger oil drain flange/tubing... but the end point is simply an o-ring'd spout...
I don't want to assume that it simple squeezes into an appropriately sized drilled hole, wouldn't the pressure (both oil in tube and volume in crankcase ) force the tube out of the hole if it just secured with an o-ring??

maybe i am being too cautious before i go beyond the point of no return... thanks in advanced for any guidance you have ^_^
 
David
Note: the drain back must dump into the oil sump above the level of oil. This is a non-pressurized return and oil will backup into the return line if mounted into the oil level in the sump.

**** now you got me thinking, I believe mine is all the way on the bottom of the pan. Not sure how it was installed by previousowner. Will have to double check when I get home. These are the instructions ZZP provides with the z57.
Screenshot_20260119_183943_Chrome.jpg
 
SwerveMonkey
I did try to source a couple oil return lines that would use a weld-less bung, but neither worked with the turbo drain port.
the screws were not the correct size and more so the holes for the flange wouldn't line up with the Z54 turbo threads...
I was in contact with ZZP and they confirmed that for the Z54 most turbo oil return flanges would not work... the flange on the housing is mated to the stock LNF or LHU oil return flange.

Now, I could figure out a way to port the stock flange into a weld-less bung, but that just seems like a hat-on-a-hat scheme.
most manuals for the ecotec family I have seen show that the turbo oil return is going into that galley circled in red from BAR-AIR's picture above.
 
SwerveMonkey
YUPE!!
that's all i need then... I gotta drill that bad boy out when i am ready to plunge

Thanks VERY much for the confirmation... will have to bookmark this in the other thread i have documenting the process.
 
David
Well I guess i just learned that pervious owner screwed up another thing. My turbo drain is going directly to the oil drain bolt. So its totally incorrect in two ways. Its below the oil level and also took access to the drain bolt. Now what options do I have to fix it correctly?

Just for my knowledge, how does the draining below the oil level effect? Im guessing with what @Desert Sasqwatch said its gravity so cant have pressure at the end.

@SwerveMonkey sorry for high jacking your thread. Its a good place to keep this all together, for the LSJ and LNF.

20260119_203618.jpg
20260119_203635.jpg
 
SwerveMonkey
@SwerveMonkey sorry for high jacking your thread. Its a good place to keep this all together, for the LSJ and LNF.
No worries mate, this is exactly what the forums are meant for.... learning and sharing knowledge so we all don't stumble like i do with the L61 engine, LoL. I'm glad i could bring something to attention though, sorry ya gotta now fix it... but you learn, yeah?

That oil connection is definitely not supposed to be to the oil drain plug o_O:eek:
Optimistically, this would work if you were running JUST ENOUGH oil to be constantly emptying out the oil pan.

If anything you could source a weld-less bung kit and place that about quater to half inch below the top of the oil pan.

If you can size it right maybe be able to add a Fumoto Valve at the spot where the drain is now if the hole is too large for the OEM drain plug to be put back in.

If the turbo oil drain is not constantly flowing by gravity or being pulled by a "scavenging pump" then the increased temps of the slow moving oil may jeopardize your turbo bearings. as long as it is draining constantly your getting new cool oil on your bearings.
 
David
No worries mate, this is exactly what the forums are meant for.... learning and sharing knowledge so we all don't stumble like i do with the L61 engine, LoL. I'm glad i could bring something to attention though, sorry ya gotta now fix it... but you learn, yeah?

That oil connection is definitely not supposed to be to the oil drain plug o_O:eek:
Optimistically, this would work if you were running JUST ENOUGH oil to be constantly emptying out the oil pan.

If anything you could source a weld-less bung kit and place that about quater to half inch below the top of the oil pan.

If you can size it right maybe be able to add a Fumoto Valve at the spot where the drain is now if the hole is too large for the OEM drain plug to be put back in.

If the turbo oil drain is not constantly flowing by gravity or being pulled by a "scavenging pump" then the increased temps of the slow moving oil may jeopardize your turbo bearings. as long as it is draining constantly your getting new cool oil on your bearings.

Im assuming it would be impossible to drill and tap ro the correct port now?
 
Ross
David, it is possible, and recommended.
Put a drain plug back in the oil pan, and drill out the girdle.
 
David
David, it is possible, and recommended.
Put a drain plug back in the oil pan, and drill out the girdle.

Im guessing if I use a drill it slowly with alot of grease to catch shaving. Then a ½" tap with grease also to limit the amount of shaving going in. Then poor oil down the hole to flush out particles that fell in.

Recommendation?
 
95Blitz
Im guessing if I use a drill it slowly with alot of grease to catch shaving. Then a ½" tap with grease also to limit the amount of shaving going in. Then poor oil down the hole to flush out particles that fell in.

Recommendation?
Also have a shop vac running with the nozzle at the bit, and every 10 or so seconds remove the bit and let the shop vac clean up even when you start to brake through the block.
 
David
@Ross I read your post, you say you used a AN10 to 7/8"-14 thread adapter which is a boss fitting (straight threads). How did you seal it up snice you dont have the o-ring groove?

If I use ½" npt by AN -10 adapter it would be ½" ID. Seems to be the same ID with the adapter you used which was AN10 to 7/8"-14 thread adapter.

Just trying to figure out what size hold to drill and tap.
 
Ross
I will seal up the threads with Loctite blue. AN10 should have 10/16" ID, and I have enough room on the adapter to redrill to the full 5/8", which I plan on doing. I want the drain to be large and easy flowing. Also, AN10 is a common size for turbo drain kits.
 
David
I will seal up the threads with Loctite blue. AN10 should have 10/16" ID, and I have enough room on the adapter to redrill to the full 5/8", which I plan on doing. I want the drain to be large and easy flowing. Also, AN10 is a common size for turbo drain kits.

Yes seems like the more flow you have the better. Im just afraid that if I tap the block boss with straight threads there wont be a good seal, snice it counts on the o-ring for sealant.

Also would like to see if I can find a AN-10 turbo flange.
 
Desert Sasqwatch
The return tube on the LNF is a press fit into a grommet, no threading in the block. There is little to no actual pressure in the return tube and dumping the oil above the oil level in the pan should not cause any undue force from the oil. The only concern would be crankcase pressure from boost leaking in.
 
David
The return tube on the LNF is a press fit into a grommet, no threading in the block. There is little to no actual pressure in the return tube and dumping the oil above the oil level in the pan should not cause any undue force from the oil. The only concern would be crankcase pressure from boost leaking in.
So in theory using an ORB without the grove should be good.
 
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