Garrett & Holset Turbo Users - Your Oil Drain May Be Too Small!

[gstryyder]

The only consideration you have to keep when saying that the oil pan level may be above the turbo return line is.... What about when the car is running and oil is being pumped through the engine? Is the oil level still higher than the turbo drain? I would think the answer to be no. Even if it is when your car is just chillin does not mean it would be when there is oil pumping through the engine meaning less oil in the pan. Why would Mitsubishi design this car to have the turbo return line lower then the level of oil when the car is running?

 

[talonDSMerr]

not saying this isn't true, just wanted to put a twist on it, if you take a bottle of manual tranny fluid and hold it straight up and down it will drain slower than at a slight angle because the sides are shaped like a funnel and air can ride up top while oil is free to drain. now if you think about it our CHRA's are shaped the same way as that bottle at the base. would it then make since for us to keep a slight angle?

Good point, but the comparison isn't the same. The bottle of manual tranny fluid isn't a "closed system" while the oil system pumping oil into our CHRA is. Air doesn't need to find its way past the oil to displace it because there is no air in the system to begin with. In the bottle of tranny fluid, it's an open system so air has to go past the bottle opening to displace the fluid coming out, making the available opening for the fluid smaller than the physical opening of the bottle.

The only consideration you have to keep when saying that the oil pan level may be above the turbo return line is.... What about when the car is running and oil is being pumped through the engine? Is the oil level still higher than the turbo drain? I would think the answer to be no. Even if it is when your car is just chillin does not mean it would be when there is oil pumping through the engine meaning less oil in the pan. Why would Mitsubishi design this car to have the turbo return line lower then the level of oil when the car is running?

It was designed for 14b's, not Holsets. Maybe the drain for a 14b does not require the line to not be submerged like Holset does, so Mitsubishi didn't have to design around that? Also, I'm not sure if the oil level in the pan differs too much when the car is running or not. All the oil in the motor/turbo doesn't pool down into the pan once the car has been shut off. How do I know? I've taken off the turbo oil feed line before without draining the oil and there was plenty left in there. The oil level in the pan will also vary depending on how much oil you put in, and so will oil pressure. The smaller amount, the lower the oil pressure and lower the oil level in the oil pan (so the drain line might NOT be submerged). However, I'm sure Mitsubishi recommends a larger amount of oil for safety to account for oil leaks or burning oil.

 

[gstryyder]

then i will just weld my return line as high as possible on the pan.

 

[donniekak]

It isn't a closed system, there is plenty of air in the oil pan and drain tube. The pressurized side is a closed system.

 

[Morphius]

It was designed for 14b's, not Holsets. Maybe the drain for a 14b does not require the line to not be submerged like Holset does, so Mitsubishi didn't have to design around that? Also, I'm not sure if the oil level in the pan differs too much when the car is running or not. All the oil in the motor/turbo doesn't pool down into the pan once the car has been shut off. How do I know? I've taken off the turbo oil feed line before without draining the oil and there was plenty left in there. The oil level in the pan will also vary depending on how much oil you put in, and so will oil pressure. The smaller amount, the lower the oil pressure and lower the oil level in the oil pan (so the drain line might NOT be submerged). However, I'm sure Mitsubishi recommends a larger amount of oil for safety to account for oil leaks or burning oil.

My point in my post earlier was, if you read any book out there on turbos and turbocharging, they reccommend having the return line piped to the pan (or block) at a point that is above the oil level in the pan. So there is no restriction in the return oil.

I can't speak to the stock system. It likely isn't submerged (ie designed right). If it is, then the better move would be to move it to a location it's not.

If people are worried about it, one could use a splitter fitting to add two return lines, just to be sure.

 

[Morphius]

Here's an actual return off a 2003 - 2005 after some more digging. (I posted a convoluted pipe earlier that is from the 3rd gen (06? and later), but I'm not sure what year.My 2005 parts book shows the pipe setup below, not the convoluted design. Although, I think the convoluted design can be used in prior years)

There is still some what of a gasket stuck on the flange that attaches to the turbo.

 

[red_devil]

So what do you guys recommend for people who are looking to install a holset? Does anyone sell a larger oil drain flange? or could I find like something above and cut it and just run a hose to the stock oil pan location?

 

[talonDSMerr]

Unfortunately, there doesn't seem to be an easy, cheap fix for this right now. Even if a vendor made a flange and hose with I.D. large enough, the drain entrance on the stock oil pan would still be a restriction. Any fix would require manually opening up the hole on the oil pan or even welding the existing hole shut and creating a new one higher up on the oil pan.

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Here is a thought, since the oil from the turbo is only drained by gravity, what if we pressurize it so more oil could be drained through the small opening on the oil pan? Similar to how setups with the turbo positioned lower than the oil pan, we could use an oil scavenge pump to shove the oil away from the turbo and into the pan. I would still like to see a larger diameter flange for the CHRA drain though.

What do you guys think? This isn't cheap, but seems like a viable option to me (if in fact the drain is the cause of our blown turbos).

 

[red_devil]

Whats the occurance of this problem?

 

[asd_gst]

i have a hx40 i plan on running on my car once i get the motor rebuilt, my brother works for dodge so i can get drain and feedlines for a holset from his work at dealer cost, so should i buy those and get soemthign fab'd up for my car and get a n/a oil pan and go from there?

 

[WIDSM]

I was planning on making some new flanges with -12an fittings on them for my hx 35, however when I bolted up my -10 one to the turbo, I noticed that when the fitting is screwed on it's already rubbing the compressor housing, so it's going to make it a little harder to fit a -12 fitting on the drain line. I was thinking that maybe if I extended the fitting and then cut the threads on it that that would work, but then you have to take into account the motor mount and having enough clearance for that. The only thing that I can think of right now is maybe have a flange with barbs and just push a large hose onto it, that would solve the problem of it rubbing the compressor housing, and it should clear. I just don't want to put all those hours into making something, only for it to not fit. If anyone has some ideas, that'd be great.

 

[asd_gst]

im going to cut teh flange off of the holsets drain line i got off a dodge truck, and my friend is going to weld a -12an fitting on it and we're going to inlarge the hole in the oil pan for the drian line, i put my holset drian line next to a extremepsi -10an drian line and the hole on the flange from extremepsi was about a 1/3 of the size that is should be

 

[benjimatt]

Ok guys I think I have it right but I need some assurance.

SO it sound like the oil feed line should be smaller because we dont want too much psi shooting into the holset. size = (-4 an)

Then for the oil not to be trapped into the turbo so that our oil doesnt start getting into the rings and everything we must install a larger oil drain. (-12 an)

Here is my confusion. is it absolutely necessary for us to open the flange at the oil pan?

also is it absolutely necessary for us to move the flange to the top of the oil pan?

I understand the concept of moving the flange on top of the pan but it seems that there are other holset users that havent had to do that and are still lasting a while.

 

[WIDSM]

Someone earlier was asking if when the car is off, if the oil level is at or above the oil drain line level, and YES it is. I had to pull my drain line off because it was too long and kinked and I was pushing oil pretty bad. When I pulled the line off the fitting at the oil pan oil came out at a pretty steady pace and again when I lowered the car back onto the ground.

Also referring to my other post, I don't understand how we're going to get a -12 line on there because there just isn't enough room; at least it doesn't seem that way to me. I was going to make some -12 fittings but on the turbo side the an line hex is only about a 1/32 away from the compressor cover and the motor mount is right below that. On the oil pan, to enlarge the hole would put it almost to the top of the pan plus you need room for the flange and fitting. The only thing I can think of is to have barbed fittings and soft line on it.

If anyone has any input for this that'd be great because I really want to make up some fittings that'll solve this problem. If I can get something that works made, then I can give the print to one of the vendors and maybe they'll start making them available for sale.

 

[99gst_racer]

One thing to keep in mind: With the engine running, there isn't 4-5 quarts of oil sitting in the pan. It's being circulated through the engine and for the most part, oil is only sitting in the sump. With the engine running, the factory turbo drain hole is definitely above the level of oil siting in the sump.

 

[benjimatt]

Now that you guys have confirmed that the oil drain on the oil pan is above the oil level.

I have an idea.

Since we really want the oil in the drain to reach the oil pan and not in the turbo what if we implemented a catch can into the design.

It would go from the oil drain to the catch can and from there to the oil pan. Also air would be vacuumed out of the oil drain instead of only by gravity. This would assure that no oil is backed up in the turbo.

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[99gst_racer]

^^^ A few things I see wrong with this idea:

* Pressure travels from high to low, so when the line with the check valve is under vacuum, it will fill with oil.
* The intake manifold sees negative and positive pressure. So when it is in a situation of postive pressure, the catch can will not be in vacuum and it will not drain. If the can is mounted below or far away from the oil pan, then it won't drain at all without vacuum.
* With a constant and consistant vacuum source, you wouldn't need a catch can at all. The ideal way to do it would be to eliminate the catch can and put the entire crankcase under vacuum. Read: dry sump.

 

[talonDSMerr]

I mentioned using an oil scavenging pump in post #108 earlier.

Putting one in the drain line of the turbo would keep oil from getting backed up in the CHRA, keeping oil draining and into the oil pan. And the way it would work, you don't have to worry about the drain on the oil pan being above or below the oil level, so there's no need to weld that shut/drill a new hole. Also, you shouldn't have to worry about whether or not the drain line is large enough, because the pump is continuously moving the oil out. You still need large enough drain from the CHRA to the scavenge pump but from the pump to oil pan, you wouldn't need to reflange the oil pan with a larger fitting. Also, because the scavenge pump is pushing all the oil into the oil pan, there should never be a situation where the oil has nowhere to go but out the turbo seals.

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[benjimatt]

I mentioned using an oil scavenging pump in post #108 earlier.

Putting one in the drain line of the turbo would keep oil from getting backed up in the CHRA, keeping oil draining and into the oil pan. And the way it would work, you don't have to worry about the drain on the oil pan being above or below the oil level, so there's no need to weld that shut/drill a new hole. Also, you shouldn't have to worry about whether or not the drain line is large enough, because the pump is continuously moving the oil out. You still need large enough drain from the CHRA to the scavenge pump but from the pump to oil pan, you wouldn't need to reflange the oil pan with a larger fitting. Also, because the scavenge pump is pushing all the oil into the oil pan, there should never be a situation where the oil has nowhere to go but out the turbo seals.

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SO im assuming when wiring this we would just wire it to the ignition.

 

[gstryyder]

One thing to keep in mind: With the engine running, there isn't 4-5 quarts of oil sitting in the pan. It's being circulated through the engine and for the most part, oil is only sitting in the sump. With the engine running, the factory turbo drain hole is definitely above the level of oil siting in the sump.

i asked about this before and got a different response... glad to see someone else with a bit of knowledge reaffirmed my thought and answered my question. i would think that if you were to just put the return line up as high as possible on the oil pan it would be just fine. a pretty simple solution, and its not that hard to do especially since you are modifying the oil pan anyways.

 

[benjimatt]

I really want to use the pump. but 220$ is a lot

 

[Morphius]

Is it compatible with hot oil?

Why not just add the largest fitting to the CHRA you can with a "T" fitting on it so you have two lines running to the oil pan? Make another attachment point on the pan for a second fitting, like 99gstt_racer did with his dual turbo setup.

 

[benjimatt]

Is it compatible with hot oil?

Why not just add the largest fitting to the CHRA you can with a "T" fitting on it so you have two lines running to the oil pan? Make another attachment point on the pan for a second fitting, like 99gstt_racer did with his dual turbo setup.

Im pretty sure the pump that he posted is made to handle hot oil.

Performance with 30 w engine oil at operating temperature
oil temp @ 120° ~ 180° (f)

 

[benjimatt]

so... I have another idea but I think I may have answered my own question.

I dont have power steering anymore. SO could I use the power steering pump as an oil pump instead.

THe only problem I could see with this is maybe the psi is too high???

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[talonDSMerr]

With the way that's positioned, how would the oil drain from the turbo freely to the pump? You have your drain line from the turbo, then the power steering pump position, which is either on the same level or higher than the turbo oil drain. Do you see what I'm saying? You want the drain line to be as close to vertical as possible before the pump, in your setup, it would be horizontal almost.