What you would do, in order for it to work properly and vent both places is run one line from the breather to a sealed catch can, then to the intake, so you could use your sealed can that has two nipples for this. Then for the pcv system all you need to do is run a single hose to a can with a breather filter on top of it. that should take care of both issues, but you wouldnt be able to do it with the same catch can

 

Everything mentioned here was the opposite of what I thought.


This is what I know: CC vapors become saturated with fuel and small portions of incompletly combusted CO, CH's and H's that build up since there is always some extent of blowby. These things attack the engine oil severly and the system needs both sides working ( intake plenum check valve and turbo/MAF pipe) to be fully operational since our cars boost. So PVC is there for a vital function in operation and just happens to help emmissions.

The problem is the PVC side lets oil into combustion causing severe knock and the MAF pipe side gets contaminated with condensed oil vapors making a messy charge. I have remedied both problems with a very small trap on each side, 100% of the oil is caught.

I do however have to change the PVC side trap oil absorbent material about 1X/week


You cannot vent any of the system and have it be good. Buschur does, but he probably changes the engine oil every 100 miles

 

Hopefully, my recent splurge of research on this subject will shed some light on this.
I read my service manual in regards to the PCV system probably 20 times, and here is everything that I have “learned” and have done/am doing so far.

I have a spare intake manifold, and have been setting it up to replace the one that is on the car, and I will be deleting the PCV valve all together.

First off, the PCV valve is more-or-less a check valve to prevent boost from getting into the valvetrain cover. The service manual outlines a procedure for checking it, and it acts exactly like a check valve.

There are two “openings” into the valvetrain cover, one on the passenger side rear, where the PCV valve connects, and one in the front drivers side side of the cover that has a tube leading into the intake. I don’t really understand why it’s like that, because when the PCV valve is open (Only under vacuum), the two ports are “fighting” each other with vacuum trying to pull out air out of the valvetrain cover. There is a runner on top of the intake manifold, leading to each port runner where the PCV gasses dump into. Now, what I did with my spare manifold is to rip out the OEM 90 degree fitting, and simply plug it with a brass plug. Here is why:

When the motor is running vacuum, both fittings are trying to draw a vacuum, hence kind of “fighting” each other. When in boost, the PCV valve is shut, and the port leading into the intake is still under vacuum because it’s pre-turbo. So, they are no longer fighting each other. Hence, the port leading into the intake is ALWAYS under vacuum. Now, my theory is that if I put a breather filter onto where the PCV used to connect, there will always be a vacuum being pulled across the manifold because I will still have the connection leading to the intake, where there is always vacuum. Seems to me like there will always be a “draft” of clean outside air running through the valvetrain cover because the intake is always pulling vacuum, and it also doesn’t appear to be a “emissions” problem because the gasses that are evacuated from the valvetrain cover will still be run through the motor, and burned off.

Now, you *might not* throw a CEL for the PCV system, but probably not AS LONG AS you plug the 90 degree fitting that leads into the intake manifold. The reason I say *Might* is because when the system is connected like stock, you are introducing NO unmetered air into the intake system. When you open up the PCV to a breather, you are introducing UNMETERED air into the system because the nipple that connects to the intake is POST MAF.

However, If you don’t plug the runner on the intake manifold you will have a huge vacuum leak and a boost leak when the motor is boosting, which is one of the symptoms of someone disconnecting the system wrong. You would basically be entering in unmetered air post MAF into the engine. That runner on the intake has a hole into each runner, so it would be like drilling 4 little holes into each intake runner if you didn’t plug that 90 degree fitting. Plus, there is no OEM electrical sensors that tie into the PCV system, so the ECU doesn’t really know if it’s working or not. (OTHER THAN THE MAF, which does VERY INDIRECTLY work with the PCV system, only because if you open up the PCV system, you introduce unmetered air into the motor due to the locations of the breather nipples.) It’s (According to the OEM service manual) just a “air system” way of getting dirty air out of the valvetrain cover and burning it by running it through the motor, either through the PCV valve (When under vacuum), or through the air intake (Pre-turbo) when boosting.

The thing that I am going to do, is run a breather where the PCV used to be, then use a catch can hooked up in the following manner. The line that is on the front drivers side side of the valvetrain cover will go into a catch can, and the other line will run to the intake (Pre-turbo). So, air will enter the valvetrain cover through the old PCV area (Through a breather filter), go across the valvetrain cover exiting through the OEM nipple on the drivers side side of the cover, through the catch can, then exit the catch can and go into the intake pre-turbo.

Now, here is the big problem: In doing that, you are introducing unmetered air into the system because of the intake nipple location. How much air, well, I don’t know that. The nipple on the Injen intake is very small, probably only about 1/8” inner diameter. So, however “free flowing” that system is for the air to go through is what will depend on if the car wig’s out and throws a CEL or not. And Yes, the car has a VERY GOOD PROBABILITY of running a little leaner when disconnecting the PCV system because you introduce unmetered air. A simple solution would be to make a nipple somewhere pre-MAF so that the air get’s metered. One problem with that is you MIGHT be introducing dirty air to be run through the MAF. This all depends on how “good” the catch can really is at getting the crap out of the air. On my car, I am going to put a nipple pre-MAF to keep from having the potential of a CEL being thrown.

So, in essence, there is hopefully a lot of typing that will help you understand how the PCV system works, and the pro’s/con’s about modifying the system.

Steve, you comment:

"The problem is the PVC side lets oil into combustion causing severe knock and the MAF pipe side gets contaminated with condensed oil vapors making a messy charge. I have remedied both problems with a very small trap on each side, 100% of the oil is caught."

...is 100% true. That spare intake manifold I bought from you, when I tool the port out, and ripped out all the pressed in ball bearings, it was dirty as hell in there with sludge and crap.



Hope all of this helps….

 

yeah in my previous supra i just ran a simplefuel filter... definetly did the job and cost me like $10. my current evo i have the weaponR catch can since it looks slick sitting on my strut bar

 

Very interesting tkklemann, im going to have to think more about your idea. but if it does work, its still using venting system. So TTP like I said is wrong.

 

I also got the WeaponR on my breather side, looks sweet.
As for the PCV, i got a small tube filled with material to soak up the oil bypass. Since the Breather side has more "force" to push the oil through the big WeaponR catch can is ok to use, but on the PCV side, i keep it short and small as possible so to not retrict the flow. I change the pcv side every other run.

 

You guys are just not getting it. Please read this post.

https://www.evolutionm.net/forums/sh...d.php?t=200793

 

hmmn, I read the first 3 pages and I had ADD set in. VERY informative though.

The thing that stuck out to me the most was putting the can between the valve cover and PCV... as in: Valve cover, line, can, line, PCV, line, ITM. This is to prevent the can from being pressurized under boost?

I was actually planning on using one of those little fuel filters, but it's just a plastic casing. I'm almost certain it would be destoried by pressure, but I'm not too sure.

I'm using a small fuel filter between my breather and intake and I have a slight oily film in my line from the valve cover to filter, and then the line from the filter to intake is super clear I'm usuing clear line for a reason

So is using the PCV AFTER the catch can and between the can and ITM super important? I don't have anything there yet, but I don't want my filter to burst and make an oily mess :P

 

Then I have a huge question. This could be coincidence..but I'm not sure.

I installed a Buschur Intake recently which on their site it recommends to purchase a breather filter being there is no nipple on the intake.

I noticed about a week or two after the install of the breather filter, that I had engine oil everywhere around the oil filter as well as by the port where I put my oil temp sensor (yes the filter is tight and there are no leaks on my driveway, so I ASSUME oil is slowly coming out while I'm driving or getting into boost).

So by having a breather filter on the valve cover, it's creating alot of pressure in the crankcase? Is it creating enough pressure to "force" oil out from my block, or am are these two events completely non-related. It just seems strange that after I installed the breather filter, this oil leak problem occured with in a short amount of time...Maybe I'm way off base here, and if I am, I apologize, but I'm trying to learn here as well...and looking now to get a Saikou dual catch can setup.

I'm no expert, so any advice would be much appreciated...

 

There will be little if any pressure if the PCV valve is working properly. A good catch can will remove much more crap than a fuel filter ever could.

 

I don't understand your first sentence. I'm assuming you mean "There is little, if any..."

Yeah, I'm sure a good catch can will be better, but for now I just used two back to back fuel filters. What the first doesn't catch, the second will. I'm sure stuff will still get through the second, but it's cheap and easy for now. Worth a shot. The car has had 60k+ with oem PCV system. I'm sure 1-2k more until I can afford a good can won't hurt.

This may be a retarded question, but after having an oil catch can, then PCV and breather vaccum is then mostly clean air. Will the engine then lightly clean it's self out from then on with the cleaner vaccum air? With the continuous oil vapors in the stock breather and PCV system dirtying the IC pipes and ITM, you'd think it'd countinualy clog up completly if the engine isn't taking most of it in. I don't know how to explain it. I'm not saying the IC pipes will totally clean themselves out, but I'd THINK that with the cleaner air moving through with no oil vapors to clog up the engine will use up the vapors and oil condinsation that is currenty in the IC pipes and ITM and potentially just be burned up... Sounds stupid, I know... :P

 

yes, its very likely the filter (im assuming you mean a small filter attached right to the valve cover) is getting saturated with oil vapors and is making the mess...if you run from that nipple where your filter is, to a catch can, you will catch those vapors and still keep your CC free of pressure

 

the fuel filters can work OK

the ONLY thing i dont like is they dont completely free up pressure, try blowing through a new one, there is back pressure, so its not going to be a completely free system, the ideal way would be running it to a catch can so the air can move freely through the system, catching the oil vapors (which in large quantity will be a black sludgy oil) in the can (obviously)

 

You still think its possible after only having the K&N breather filter (off the valve cover) on for only 2 weeks, that it could be the cause?

I find it hard to believe, but I have no other reasoning why there is oil down by my oil filter and at the plug where I put my oil temp sender (right above the oil filter).


I'm not sure if I'm being completely clear in my first post there...

 

no ive seen those breathers do that before, and on a forced induction application its going to be worse

plus if you havent changed anything BUT that, then its really the only thing that could be causing it