Wits End Turbo Owners

[alia176]

I figured HOTTTT oil + gas do not mix well with plastic so I went for this one that's made of aluminum, has o-rings. and threaded holes for intake + output to make sure it seals.

Internal baffle system seems questionable so I bought coarse copper wool to put inside to increase surface area for cooling gas + oil.
Hose and clamps look like garbage, too so I'll use some high-quality hose. I need to measure ID on PCV and breather side but off the top of my head, it looks like 1/2" ID on breather and 3/8" ID on PCV would work.

Added to my Amazon wish list, thank you bud! As stated, please show us pics after you're done with the project.

 

[CJK]

catch cans arrived but hose and clamps did not arrive yet.

I found (2) spots that look decent and far enough from hot stuff that the gas can cool so oil and nasty stuff stays in the catch can

PCV Catch Can

—> mounted on fender wall in corner near brake booster. There’s a few bolt holes already drilled and tapped so I just need to make a quick bracket.

Breather Catch Can
I don’t have a dual battery setup, so I have tons of space on left side. I found a nice little pocket between air box and fender wall that is dead space. Again, found holes but need to fabri-cobble a bracket.

I want them out the way, but not in a place that’s inconvenient to access them, otherwise, I probably won’t empty them and I’ll be in the same spot as I am now.

 

[Enders]

Very curious about the catch can setup. Noticed I’ve got some oil residue on the bottom of the turbo housing too after wheeling and cruising up and down the Appalachians. I rather enjoyed smelling the turbo burn off the last of its factory coating

 

[CJK]

not that $25 per can is much, but you can buy Amazon Warehouse “Used Like New” for $16 each right now

Ruien Polish Baffled Universal Aluminum Oil Catch Can Reservoir Tank Black Amazon product ASIN B06XK9PTP7

 

[Wompom]

I hate to be the bearer of bad news, but I just removed that exact can from my turbo setup per advice in this thread about my oil in turbo issue. It caused enough pressure differential to send oil through the breather and thus into the turbo. I may reinstall with less filter material in it and see if that works, but as of now it’s running much nicer without the can. A good baffled can is worth the money. I tried the cheap Amazon way and well it’s out now. Curious how yours ends up.

Before I cleaned up the lines

 

[alia176]

@Wompom that sucks mucho, sorry to hear it.

I wanted to remind everyone of the PCV air travel path. It's been mentioned in great detail some pages back but here's visual!

 

[CJK]

I hate to be the bearer of bad news, but I just removed that exact can from my turbo setup per advice in this thread about my oil in turbo issue. It caused enough pressure differential to send oil through the breather and thus into the turbo. I may reinstall with less filter material in it and see if that works, but as of now it’s running much nicer without the can. A good baffled can is worth the money. I tried the cheap Amazon way and well it’s out now.

Well…damn. I missed that thanks for the heads up

 

[CJK]

I wanted to remind everyone of the PCV air travel path. It's been mentioned in great detail some pages back but here's visual!

I actually didn’t know this.

I knew air went PCV to Intake, but didn’t know breather was a “sucking hole”.

So assuming that is true, seeing oil in the breather line means:

1) PCV is causing back pressure

2) breather thus becomes an “overflow PCV” to bled excess pressure.

 

[Enders]

So, where exactly should the catch can go? Pictures are helpful.

 

[Wompom]

the catch can should go between PCV and intake, as well as on the breather if you have a 2 port. If your catch can doesnt flow freely, you end up with a venturi effect where it either sucks oil into the breather, or uses your breather instead of the PCV to relieve pressure (which is what i think i encountered). Probably similarly why those running the home depot air compressor catch cans are seeing them fill on both sides?
I'm going back to no catch can. Truck runs much smoother and i'll deal with cleaning the intake whenever i take it off next if needed.
Or i'm going to suck it up and spend the few hundred bucks on a properly designed catch can.

 

[CJK]

the catch can should go between PCV and intake, as well as on the breather if you have a 2 port. If your catch can doesnt flow freely, you end up with a venturi effect where it either sucks oil into the breather, or uses your breather instead of the PCV to relieve pressure (which is what i think i encountered). Probably similarly why those running the home depot air compressor catch cans are seeing them fill on both sides?
I'm going back to no catch can. Truck runs much smoother and i'll deal with cleaning the intake whenever i take it off next if needed.
Or i'm going to suck it up and spend the few hundred bucks on a properly designed catch can.

I’ll try the “suck it up and spend the money” method. I’m in this far on the turbo and my LC, I’d rather just dish out the money to do it right the first time.


I’m looking at the Moroso, Radium Engineering, and Mishimoto catchcans.

 

[alia176]

I actually didn’t know this.

I knew air went PCV to Intake, but didn’t know breather was a “sucking hole”.

So assuming that is true, seeing oil in the breather line means:

1) PCV is causing back pressure

2) breather thus becomes an “overflow PCV” to bled excess pressure.

Here're the pics from few pages back. Now that I understand the air flow direction better, I need to turn around this separator. But, I'm intrigued at how the unit is still trapping oil even though it's on backwards. Unfortunately, my compressor still shows some oil pooling.

 

[alia176]

I’ll try the “suck it up and spend the money” method. I’m in this far on the turbo and my LC, I’d rather just dish out the money to do it right the first time.


I’m looking at the Moroso, Radium Engineering, and Mishimoto catchcans.

These guys seem to have catch cans for the turbo diesel crowd, might be worth a looksie.

 

[CJK]

wow so I just had a thought...although it may not be right

We're currently operating under the assumption that Crankcase is excessively pressurized causing overflow pressure to seek low pressure at the intake and taking dirty oil/fuel/air mixture ("goop").

What if the crankcase pressure is not excessive, but rather the increased air volume/velocity caused by the turbo is creating venturi effect over the Breather Tube Hole, which results in sucking "goop" from the crankcase breather.

 

[alia176]

What if the crankcase pressure is not excessive, but rather the increased air volume/velocity caused by the turbo is creating venturi effect over the Breather Tube Hole, which results in sucking "goop" from the crankcase breather.

That's an interesting thought, and that might explain why my air/oil separator that's installed backwards is actually collecting oil and filling up!!! That breather tube is on the negative pressure side of the compressor, so your logic seems sound to me. Since my "real" PCV air/oil separator is also filling up, this tells me that enough air is going into the valve cover (from the breather tube) to help evacuate the oil vapors out of the valve cover.

 

[CJK]

That's an interesting thought, and that might explain why my air/oil separator that's installed backwards is actually collecting oil and filling up!!!

Is there a reason why Mr. T would not have put a one-way valve on the breather tube? I understand why PCV is 1-way as that would essentially be a vacuum leak.

I suppose that sufficient restriction of crankcase valve would result in BANG.

I guess we could test by venting an oil catch can off breather to atmosphere and measuring vacuum/pressure from the intake breather tube

 

[alia176]

Is there a reason why Mr. T would not have put a one-way valve on the breather tube? I understand why PCV is 1-way as that would essentially be a vacuum leak.

I suppose that sufficient restriction of crankcase valve would result in BANG.

I guess we could test by venting an oil catch can off breather to atmosphere and measuring vacuum/pressure from the intake breather tube

Technically, the left port on the valve cover is merely a "breather tube" that is open to the atmosphere. Fresh air goes into this port, dirty, oily air leaves the second port on the right side of the valve cover.

 

[CJK]

Ok, my understanding goes further thanks to this Turbo Forum

Whether NA or boosted, the goal of the both the PCV and the vent is to evacuate this crankcase pressure.

For a NA vehicle, the PCV is only sucking fumes out of the crankcase when the amount of vacuum below the throttle plates is high enough to overcome the valve in the PCV. And as the throttle plates open, which decreases the manifold vacuum allowing the PCV to close, there will then be a vacuum created above the throttle plates where the crankcase vent (usually on the valve cover) is attached to the air cleaner. The entire goal of this system is to have a vacuum created on the crankcase no matter the position of the throttle plates.

The same applies on a boosted engine with a couple of minor addendums. When in boost, the amount of crankcase pressure is significantly higher due to the cylinder is not being filled via vacuum only - the turbo is actually pressuring the cylinder at a greater rate than when NA due to the increased pressure in the cylinder. The amount isn't additive to atmospheric pressure, but is more dependent on the level of boost and the condition of the rings and sleeve (bore). To say that there is more crankcase pressure with a boosted than NA motor is accurate.

Regarding putting your vent from the valve cover to the filtered air intake pipe, yes that will work just fine, but I would never do it. If you are at all familiar with filling your CAC system with compressed oil vapor, you'll know why I feel that way. If for some reason you have cylinder sealing failure you will find your compressor wheel, CAC and intake to contain alot of oil that leads to a detonation prone condition in your motor.

Here's what I'm doing, and I'm not saying this is the best system but it does work very well, I have a check valve in my intake that the PCV hose is hooked to so as to keep boost from getting past the PCV because the PCV will not seal boost (as someone else mentioned). I have the vent hooked to a vented catch can that also has another port hooked to a vacuum pump that is activated whenever the boost level is at .5 psi. I'm using an MS to trigger the pump, but a Hobbs switch and relay would work just fine as well.

My takeaway from this is that the reasons we may be seeing oil through the breather:

1) Boost is leaking from manifold through PCV valve which pressurizes the crankcase and causes gases to seek low pressure at the intake.

2) PCV is unable open anytime the engine is under boost since the manifold is High Pressure and crankcase Lower Pressure. This makes the breather the de facto method for gas to escape.


It sounds like the way forward is this:

PCV
1) Install check valve between PCV and manifold to prevent boost leakage
2) Install high-flow baffled catch can to capture fluids

Breather
1) Install vented catch can

*Unsure if vacuum pump needed at this time. Depends on things I haven't figured out yet
Link about vacuum pumps
Dudes (maybe some chicks, too) talking about inexpensive electric vacuum pumps

 

[RoaringFork]

@Wompom that sucks mucho, sorry to hear it.

I wanted to remind everyone of the PCV air travel path. It's been mentioned in great detail some pages back but here's visual!

View attachment 2773974

Ok, the PCV system flows as follows:

^^^
When the manifold is under vacuum, and there is enough crankcase pressure to fulfill said manifold vacuum…

^^^
when the manifold is under vacuum and crankcase pressure has been evacuated. This is an unsealed system, instead of pulling a vacuum on the crankcase, vacuum is “vented” through the breather hose. The air pulled through the breather hose, through the valve cover and into the manifold has already been “accounted for” by the MAF and is burned just like the air that went through the throttle valve.

^^^
when the manifold is under boost pressure. boost pressure acts on the PCV and holds it shut(so crankcase won’t pressurize). The suction is now on the fresh air side going into the turbo. Any crankcase gas will be drawn through the breather hose into the turbo inlet, and back into the engine…

 

[CJK]

@RoaringFork - thanks for the explanation and visuals. That totally makes sense and where I was slowlyyyyy getting to