Oil catch can - using T to connect PCV and breather???

[tsi1991awd]

So I'm installing a catch can that I made from a Husky filter element used for air compressors. It has one in and one out on it. Can a T fitting be used to connect the PCV and breather hoses and then have one hose into the IN portion of the catch can?

I'm not sure if the T will interfere with oil flow into the can (if any oil comes out at all) that is my main concern.

 

[DougR]

64175 And it has a arrow on it showing flow direction.
Buy a couple of them, I bought 15 and resold them at a price that got mine for free. Along with braking one of them.

 

[tsi1991awd]

I already bought 5 of the 80 cent ones.

I went down the road and back, did a hard pull until 3rd gear. When I came back, I looked at the catch cans and the one for the VC breather didn't have anything but the one for the PCV had some oil in it. And the oil was "flowing around" inside, I assume because of the vacuum. Do you think it filled under boost because I don't have a check valve?

 

[No_Skillz]

Dude, you gotta get a checkvalve. The crank case is not designed to see pressure. Furthermore the pressure in the block will leak out many different places, meaning your running extremely rich, everything is laggy, and your turbo is hating right now for making it work extra.

Because of what I've stated, that question is too muddled to answer right now. Without a valve there, you have airflow going both ways and oil can be coming from either end, and there are several sources which further need to be narrowed down.

And don't run a checkvalve on the intake-VC side of things. It's SUPPOSED to flow both ways.

 

[DougR]

I already bought 5 of the 80 cent ones.

I went down the road and back, did a hard pull until 3rd gear. When I came back, I looked at the catch cans and the one for the VC breather didn't have anything but the one for the PCV had some oil in it. And the oil was "flowing around" inside, I assume because of the vacuum. Do you think it filled under boost because I don't have a check valve?

Thats exactly right. Its doing its job of catching the oil from blowby. Problem is that home depot filter is not designed to do what your making it do. They are meant for low flow and small amounts of air compressor oil and condensation. NOT high volumes of oil contaminated air.

It WILL let the oil pass right through it and into the intake. (now it Will trap some. but a very small portion of what is flowing through your system)
That is exactly why our vendors make the CC's as large as they do with a Baffle inside it. To SLOW and allow the hot gasses to expand, Thus allowing the vaporized oil drop OUT of the air stream and stay contained in the CC.
Im going to keep my opinion about those home depot cans to myself.

 

[No_Skillz]

Vaporized oil? I would be worried about driving out of a firestorm before worrying about the catchcan if it was vaporized. Besides, if properly maintained, it's supposed to be low amounts of oil. If our cars truly needed those huge advertised cans, they would have stopped running long ago.

 

[tsi1991awd]

So technically with the check valve, there is no need for the actual PCV valve, am I right? If the cheap check valve is doing the job of the PCV....

 

[DougR]

Its called, As you know "Blow by" and everyone has different amounts of it..
Some guys can get away with the tiny cans as described above (tight well sealed rings, Vs loose and leaking rings). Some cant as this guy is finding out. Since his has already filled with oil. The US plastic check valve will help his situation some as it will Slow the flowrate and help trap some of the oil. But I bet ya He starts popping his dipstick again.

As described above the PCV does more then just act as cheap checkvalve, its also a metering device that controls the flow rate of the PCV system as a whole. This is where guys with excessive Blowby pop didpsticks. The blowby as exceeded what the PCV can vent. Causing high crank case presshures.
Once you get to that point, Yess removal of the PCV and inserting a brass barb Stops the didpstick pop. But does nuthing to cure the problem..

A CC is merely a bandaid for excesive Blowby or a way to stop oil from spilling all over the track and engine bays (for high boosted Track cars). But for a DD car its to stop the oil from entering the intake system.

 

[No_Skillz]

So technically with the check valve, there is no need for the actual PCV valve, am I right? If the cheap check valve is doing the job of the PCV....

You could probably get away without a PCV.

Some guys can get away with the tiny cans as described above (tight well sealed rings, Vs loose and leaking rings). Some cant as this guy is finding out. Since his has already filled with oil.

Right now I fear that the oil is from is intake due to not running any kind of valving. Hopefully a checkvalve will eliminate this symptom. This leads us to...

As described above the PCV does more then just act as cheap checkvalve, its also a metering device that controls the flow rate of the PCV system as a whole. This is where guys with excessive Blowby pop didpsticks. The blowby as exceeded what the PCV can vent. Causing high crank case presshures.
Once you get to that point, Yess removal of the PCV and inserting a brass barb Stops the didpstick pop. But does nuthing to cure the problem...

I'm not sure how much of a metering effect the PCV has and why a checkvalve couldn't acocmplish the same thing. As to your second point, keep in mind that there is a VC breather, and that is made to handle most blowby. Of course, it could be overwhelmed, which leads us to:

Its called, As you know "Blow by" and everyone has different amounts of it..

Point very well taken. Arguments about catchcan size aside (say that 5x fast) I want to get OP to have the correct functional setup first before any blowby troubleshooting starts. Right now his situtation is difficult to assess because oil can be coming from anywhere and everywhere. If his blowby does end up being overwhelming, it would definitely make sense to upgrade to a larger can, and at that point I would also advocate a large, well-constructed, baffled can from a vendor.

 

[tsi1991awd]

You could probably get away without a PCV.



Right now I fear that the oil is from is intake due to not running any kind of valving. Hopefully a checkvalve will eliminate this symptom. This leads us to...



I'm not sure how much of a metering effect the PCV has and why a checkvalve couldn't acocmplish the same thing. As to your second point, keep in mind that there is a VC breather, and that is made to handle most blowby. Of course, it could be overwhelmed, which leads us to:



Point very well taken. Arguments about catchcan size aside (say that 5x fast) I want to get OP to have the correct functional setup first before any blowby troubleshooting starts. Right now his situtation is difficult to assess because oil can be coming from anywhere and everywhere. If his blowby does end up being overwhelming, it would definitely make sense to upgrade to a larger can, and at that point I would also advocate a large, well-constructed, baffled can from a vendor.

Here is what happened....I went down the street and came back home. The catch can had maybe 1/6th of oil in it...that is if you divide the catchcan into 6 parts, only 1 of those parts had oil in it. The vacuum was making it run up the sides of the can....it looked like if you put water on glass and blew on it, it makes ripples and waves...that's what it looked like.

2 hours later I drove to work, when I got to work I checked the can and there was hardly any oil in it. I didn't hit boost once....so I'm assuming all the bouncing around on the roads along with the vacuum from the intake manifold caused all the oil to be sucked up.

So I don't know....I can't say much until I get the check valve. Im thinking maybe because I hit boost earlier, pressure built up in the system and then once I was out of boost, the pressure released and shot oil into the catchcan and the vacuum assisted in sucking it through. Only a theory....but there isn't even a drop of oil in the BREATHER catchcan...only in the PCV catchcan.

I read up on the PCV for our DSMs and they only open when there is vacuum. They close when there is boost.

Knowing that, I don't see why a check valve and a barb fitting wouldn't work. I mean, there will be constant vacuum while driving, so I don't know if that will cause oil to be sucked up or not but the check valve will do just what the PCV is supposed to and that is let vacuum through (PCV open) and stop boost from entering (PCV closed)

Well I cut the tube going from the intake manifold to catch can and I plugged it. I disconnected the PCV from that catch can as well. I hooked the PCV and breather to the catch can going to the intake. I drove around, boosted, etc. There is no oil in the catch can. There was a bit of "fog" in the catch can and a few black specs of oil but there isn't anywhere near how much was in the PCV catch can.

Since the PCV only draws out blowby during vacuum, I'm wondering how much it is actually doing. If this was an N/A motor, then I would say leave the PCV hooked up for sure....but being a turbo motor, you boost just trying to get up to the speed limit, so.....maybe having both the PCV and breather hooked up to the intake is alright, I don't know.

 

[No_Skillz]

Oy I thought you had started to understad how the system worked... back to square one:

The PCV doesn't just draw out blowby when it's open. It pulls in fresh air from your VC breather, CIRCULATING the air in the crankcase. This helps get rid of fumes and vaporized contaminants and preserves your oil.

When you are boosting, PCV is closed and it's the VC breather that DRAWS blowby - there is a vacuum at your intake due to your turbo sucking.

 

[tsi1991awd]

No, I understood exactly what you were saying. My main concern is the PRESSURE build up inside the crankcase, and then blowby gasses second.

I understand that the PCV sucks in fresh air via the breather and then closes when boosting, then the turbo is pulling blowby out through the intake. I understand that concept.

I'm just trying to keep pressure out of the crankcase so it doesn't blow the dipstick again, which the way I set it up now, it has done. I boosted all the way to work just fine with just a very little bit of oil in the can...like 4 drops worth.

Blowby is the second concern and I believe the vacuum created by the intake and the boost created will draw blowby out, maybe not ALL of it, but it will draw it out if its keeping the pressure out.

I change my oil every 2500 miles anyways, so I'm not all too concerned. Maybe I should be...

 

[fuzzydoodle]

If you eliminate any of that system, you're defeating its purpose. If you don't have a PCV valve that closes under boost, you boost your crankcase, and the dipstick tube pops and sprays oil all over the place.

It might sound like your just not reading the facts, kenamond showed you the way, you just didnt hold his hand.

Now maybe I didnt catch the change, but from my understanding you have not put a pvc valve back in? Why?

If you don't have a PCV valve that closes under boost, you boost your crankcase, and the dipstick tube pops and sprays oil all over the place.

And from what it sounds like this is your main concern, the dipstick, minutia, worry about bigger problems.
If you have a PCV valve which is positive crankcase VENTILATION, not valve (btw), you wont be "boosting" your crankcase.
The out on the side of the valve cover is essentially an exhaust, for lack of better wording, when under boost pressure keeping the pressure to a minimum (or within operating range).

Your PCV valve will negate any pressure leading into your crankcase when your manifold is being pressurized, I.E., B|O|O|S|T, just put the system the way it is suppose to operate and you wont have these problems.

So unless I myself am way off, your boy kenamond showed you they way, you just chose not to follow.

 

[No_Skillz]

It might sound like your just not reading the facts, kenamond showed you the way, you just didnt hold his hand.

He's holding MY hand... and I've got my priest robes on.

We're discussing the use of a checkvalve instead of a PCV. In the meantime, while wer're waiting for the parts to arrive, we have to find a setup he can run for now. We also have to impart all of our wisdom about the PCV system so that he sets it up correctly when the parts get there.

Btw, thanks for the catch on V-for-ventilation.

No, I understood exactly what you were saying. My main concern is the PRESSURE build up inside the crankcase, and then blowby gasses second.

You can indeed run your setup as described for now. But when those checkvalves come in, install it like we discussed.

 

[tsi1991awd]

The check valves will be in on Tuesday. I'm going to install two of them like this: bard fitting - check valve - catch can - check valve - intake manifold....just as a safety. I don't think that will hurt anything.

Right now I have the barb fitting hooked to the T, and the breather hose hooked to the T and the catch can hooked to the last nipple on the T and then hooked to the intake pipe.

 

[fuzzydoodle]

He's holding MY hand... and I've got my priest robes on.

Yeah he may be, only I was saying as far as comprehensive explanations, kenamond done did it, even for me, I was like, wow, that makes it seem really simple.

My main concern is the PRESSURE build up inside the crankcase

This is what I am talking about, its being made all so confusing, because of a stupid barbed fitting, what is so special about this fitting?
Have you developed a bond with it?
Drive down to the mitsubishi dealer, pick up a 7 dollar pcv valve and put it in. Done, no problems, and everything works, put the catch can on the vc to im side, and in a few days splice in a check valve.

All problems fixed.
AND it works like it is SUPPOSE to...
Somebody better be going to the moon cause WAY too much rocket science is involved in this task.

 

[No_Skillz]

Drive down to the mitsubishi dealer, pick up a 7 dollar pcv valve and put it in. Done, no problems, and everything works, put the catch can on the vc to im side, and in a few days splice in a check valve.

All problems fixed.
AND it works like it is SUPPOSE to...
Somebody better be going to the moon cause WAY too much rocket science is involved in this task.

Give a bum $10 or teach him how to make $10...

 

[fuzzydoodle]

Why cant you give him 10 and ask him if he wants to learn how to make another 10?

Anyways, point being, it has been explained in great detail. So assuming you understood the explination from both of you (yourself and the previously stated) on how the system works, the answer should be clear.

To me it just seems like he is grasping onto this barbed fitting, for whatever reason, and even after he says "I will use it like this: barbed fitting | check valve | catch can | check valve | intake manifold".

For what? Is what I am trying to teach the bum, for what?

He probably still has the pcv valve around his house, put it in, put the catch can, then the check valve and it will work fantastic, and serve functional.

 

[No_Skillz]

Dude... the barb fitting is a minscule detail to the entire PCV system. I'm helping him with his setup with a barbed fitting because that's what he has and that's what he's stated he'd like to run. Besides, if we all did things the same way, that'd be pretty boring, don't you think? Why are you complaining about other people spending too much time to help others? Is there anything of a helpful, technical nature that you would like to add?

 

[tsi1991awd]

Why put words into my mouth fuzzydoodle? I understood what the hell he was saying all along. I'M SAYING I'm not running a damn PCV, I'm running the barb fitting. I already tapped the damn hole for it and the PCV isn't going to thread in...and I'm not going to retap it.

If you're so stuck on me putting a PCV back in, why don't I just shove it in the hose after the barb fitting...it'll accomplish the same ####ing thing. The setup I'm running at this current time is accomplishing what I need it to. I don't care about opening at vacuum, closing at boost, blah blah. I get it...I get the point, I understand the concept. The opening, closing, circulating fresh air and other shit isn't my concern. I don't care about it. I just wanted the pressure out of the crankcase and I accomplished it. When the check valves come in, I'll put on it and hook the other can back up.

 

[fuzzydoodle]

No, I mean no offense, I am just questioning the OP on the point of the fitting, only because of what he is worried about was the pressure, so putting the valve back in would fix his problem.

So dont get heated just yet, yes, originality is good, no, I dont have problems with you helping anyone, just questioning methods.

 

[kenamond]

Although it's already been said, V is for ventilation, a PCV valve is a metering orifice in addition to a check valve (oldman was posting a good article about PCV a couple years back), and a PCV valve from Mitsu is about $8 and WORKS!!! I've bought two in the past two years (only needed one, but got a 2nd when I suspected the 1st has started leaking...it didn't, but I replaced it anyway).

If you think about it for a second or three, the PCV valve under idle is giving intake air a shortcut around the throttle body. The IASC and BISS are in the throttle body, and it is their job to properly maintain idle. If you give air an unobstructed shortcut around the throttle body, your idle will show it. That's why the PCV valve only lets a certain amount of air past when it's open.

I would not use a **barbed** (not "bard") fitting and a check valve. I would use an OEM PCV valve and a check valve. If the PCV valve starts to leak under boost, the check valve will back it up and keep boost leaks away, but you'll still have the metering effect of the PCV valve, and you have the ***snorkel***.

What's the snorkel, you ask? It's a bronze tube that sticks out of the stock PCV valve. When installed, this bronze tube extends into the open air under the valve cover behind the baffles. It lets the PCV valve breathe in crankcase air without sucking in oil that's running down the inside surface of the valve cover. If you run a barbed fitting on the VC, you are most likely sucking in oil under vaccuum. That's ending up in your catch can and ultimately in your intake manifold, motor, turbine housing, DP, and exhaust.

If you have a Husky "catch can" on your VC breather line, read the chemical compatibility information on the sticker on its side. It says that it's not to be used with gasoline. Polycarbonate (the bowl is made of it) is not compatible with gasoline. When the VC breather and catch can are "needed" is when you are boosting and the PCV valve is closed. During the compression and power stroke, the blowby past the rings is ***unburned air/fuel mix***. And that's what's going out your VC breather line. And it has gasoline in it. I'm not sure if it's a big deal or not, because several folks have had success with these cheap catch cans, but it's worth knowing.

I personally have a steel fuel filter with internal filter element ($8 at NAPA) as my VC breather filter. There's an inlet on one end and an outlet on the other, and no other openings. I used extra vaccuum line so that the filter hangs vertically with the lower end connected to the VC breather nipple. That way, if there's any standing oil accumulating in the filter, it'll drain downward under gravity and be sucked back into the valve cover when I'm under vaccuum. Unless you're going up a long hill or towing a boat, you're under vaccuum A LOT more often than you're under load.

I still haven't installed the USPlastics check valve on my car, but...I don't need to. The $8 PCV valve is properly functioning with its metering, check-valving, and snorkeling. Regular boost leak tests tell me when it starts to leak, and I'll go buy another $8 OEM valve when it does.

It should be becoming clear that the PCV *system* is a system that integrates with and affects other systems. If you don't understand this stuff, don't mess with the PCV system design. A bit of oil in your intake tract is better in my opinion that popping your dipstick, contaminating your oil, messing up your idle, and sucking oil into the intake manifold.

 

[fuzzydoodle]

I get it now, as I stated before "unless I missed something", which apparently I did, no biggie, I didnt know your valve cover was stripped and re-threaded. Nor was I putting words in your mouth, simply quoting.

So for any confusion I apologize.
So as a retracted statement, in your situation, this is going to have to work, unless you wanted to buy a new powder coated valve cover.

But for others with the same question, a barbed fitting is not recommended.

And swear words? Honestly, I am from your region, we probably will be attending the same meets, dont be silly, be mature.

(On a side, I have the husky CC on the vent side of the case and read that sticker too, I wondered about it but after 2 years the thing still holds up great, looks like garbage, but works great)

 

[kenamond]

I admit that I didn't read every post. If his VC is stripped and re-threaded, I'm not sure what to say. I've never ripped the baffles out of a VC to see what it looks like near the stock PCV valve, but if it seems okay, maybe drilling/tapping a hole next to the stock location so that it'd accept the stock PCV valve threads and plugging the old hole would be one option. I'm not sure, but there might be stuff in the way outside of the VC that you'd have to consider (there's a plug mounted nearby and the fuel rail and throttle cable). Or maybe he could fabricate a snorkel from bronze tubing, slip it through the barbed fitting and put a clamp on the hose to hold the snorkel in place or JB weld the snorkel into the barbed fitting. Just be careful that snorkel can't fall into the head...that might be a bad thing.

 

[DougR]

The brass tube is exactly what I'm thinking.
Just Solder it into the ID of the barb fitting, With a small pencil torch.

Possibly fold over the End of it inside the VC and drill a small hole that matchs the ID of the PCV "snorkel". Also solder the fold shut.

 

[tsi1991awd]

I get it now, as I stated before "unless I missed something", which apparently I did, no biggie, I didnt know your valve cover was stripped and re-threaded. Nor was I putting words in your mouth, simply quoting.

So for any confusion I apologize.
So as a retracted statement, in your situation, this is going to have to work, unless you wanted to buy a new powder coated valve cover.

But for others with the same question, a barbed fitting is not recommended.

And swear words? Honestly, I am from your region, we probably will be attending the same meets, dont be silly, be mature.

(On a side, I have the husky CC on the vent side of the case and read that sticker too, I wondered about it but after 2 years the thing still holds up great, looks like garbage, but works great)

You were trying to make me out to be an idiot...nevermind, misunderstanding.

How about if I stick a PCV after the barb fitting but before the catch can. Wouldn't that still be doing its job? Then I can have the check valve after the catch can but before the intake manifold. Therefore, there will still be a metering effect but it won't be IN the valve cover.....not 100% sure if that'd work or not. All I know is a PCV will not thread into the VC now.