PCV Help?

[daredevil95]

Hi, I just got done installing a rebuilt engine. Prior to the rebuild, the PCV was in the intake and connected to nothing, oil everywhere....The PCV hose coming off the vacuum block had a bolt in the end of it. It was like this for over 10 years. Since it's now rebuilt, I don't want that BS anymore and I installed a catch can. Basically I have a new PCV in the intake, new gromet and a hose that runs from the pcv straight to the catch can. My concern is, I was reading a bunch of old posts and a lot of the posts mention a check valve? Something to do with boost IDK? In my current set up (pics below) do I need a check valve & do I have the pvc oil catch can setup properly? The actual can is up front driver side behind headlights (only space I have). I am getting close for the first start and this is a item of concern and I'm sure I'll be asking a couple more questions in the next few days. I'm addressing one problem at a time. Thanks in advance.

Gene

 

[MikeS]

I've tried a number of different pcv setups, here is what i currently run: PCV > non- vented catch can > turbo intake pipe. I drilled and tapped the pipe after the MAF but before the turbo. This way there is always suction on the pcv whether the engine is idling or seeing boost. There is no chance of boosted air leaking past the pcv. I've seen the least amount of oil leakage like this.

 

[daredevil95]

I've tried a number of different pcv setups, here is what i currently run: PCV > non- vented catch can > turbo intake pipe. I drilled and tapped the pipe after the MAF but before the turbo. This way there is always suction on the pcv whether the engine is idling or seeing boost. There is no chance of boosted air leaking past the pcv. I've seen the least amount of oil leakage like this.

Ok, I have that extra port on my catch can so, basically a run a hose from that extra port (in pic) to the pipe after the MAF. That's no problem, I need a nipple and connect hose. Will the turbo suck any oil in? If catch can starts to collect oil? Once car is completed, I use this GN as a daily driver....it's not a once in awhile driver. Thanks

 

[Chuck Leeper]

1. The breather in the valve cover should move up to the oil fill neck.
2. Unless the catch can has a vac source it's not going to work well.
Here's how to plumb a can that works. Not cheap, but they work!

Mightymouse Catch Cans

Custom catch cans and complete crankcase ventilation systems for performance, specializing in high power, high flow oil consumption and pressure solutions.

www.mightymousesolutions.com

 

[MikeS]

Ok, I have that extra port on my catch can so, basically a run a hose from that extra port (in pic) to the pipe after the MAF. That's no problem, I need a nipple and connect hose. Will the turbo suck any oil in? If catch can starts to collect oil? Once car is completed, I use this GN as a daily driver....it's not a once in awhile driver. Thanks

Yes, run an extra hose from the unused fitting to the turbo intake pipe. You can get a 90 degree fitting from home depot that is barbed on one side and threaded on the other. Make sure the catch can has appropriate filter material to capture oil vapors in the air as it passes through. Most of the ebay catch cans are simply empty. On mine, I fabricated an internal hose under neath the "in" port to keep air from simply crossing port to port without filtering out the oil. I also ringed the inside of the can with fine screen material to ensure none of the filter medium gets sucked out by the turbo. Yes, your turbo could suck in oil if you don't empty the can, but I imagine you'll get about a teaspoon of oil in it every 1k miles or so, so just check it periodically.

 

[daredevil95]

1. The breather in the valve cover should move up to the oil fill neck.
2. Unless the catch can has a vac source it's not going to work well.
Here's how to plumb a can that works. Not cheap, but they work!

Mightymouse Catch Cans

Custom catch cans and complete crankcase ventilation systems for performance, specializing in high power, high flow oil consumption and pressure solutions.

www.mightymousesolutions.com

nice stuff but, not in the budget at this time. Maybe in the future. thanks

 

[daredevil95]

Yes, run an extra hose from the unused fitting to the turbo intake pipe. You can get a 90 degree fitting from home depot that is barbed on one side and threaded on the other. Make sure the catch can has appropriate filter material to capture oil vapors in the air as it passes through. Most of the ebay catch cans are simply empty. On mine, I fabricated an internal hose under neath the "in" port to keep air from simply crossing port to port without filtering out the oil. I also ringed the inside of the can with fine screen material to ensure none of the filter medium gets sucked out by the turbo. Yes, your turbo could suck in oil if you don't empty the can, but I imagine you'll get about a teaspoon of oil in it every 1k miles or so, so just check it periodically.

That's good info, thanks. My can is a empty, what is the material I should stuff into can? or I might look into another can with filter material already i it? Thanks

 

[daredevil95]

Yes, run an extra hose from the unused fitting to the turbo intake pipe. You can get a 90 degree fitting from home depot that is barbed on one side and threaded on the other. Make sure the catch can has appropriate filter material to capture oil vapors in the air as it passes through. Most of the ebay catch cans are simply empty. On mine, I fabricated an internal hose under neath the "in" port to keep air from simply crossing port to port without filtering out the oil. I also ringed the inside of the can with fine screen material to ensure none of the filter medium gets sucked out by the turbo. Yes, your turbo could suck in oil if you don't empty the can, but I imagine you'll get about a teaspoon of oil in it every 1k miles or so, so just check it periodically.

This looks good?

Amazon.com

 

[Chuck Leeper]

 

[MikeS]

This looks good?

Amazon.com

No, use the catch can you have. One with a breather will allow unmetered air into the system (giant vacuum leak). Fill yours with stainless steel scouring pads from the dollar store. The ones that look like a continuous spring wound into a ball, not brillo pads that flake apart into tiny metal fibers.

 

[THensley]

If you can't afford a proper catch can for a boosted car. I would use RJC Racing PVC and plum it OEM style. as per Jason instructions.
You can't screw up a naturally aspirated catch can. But a boosted car you can make things worse.
You have been given a mixed bag of suggestions And like the Night in The Last Crusade , fames words
HE CHOSE POORLY you don't want that to be you.
Chuck sent you GOOD Info for people making cans for boosted cars
I run a system from CorkSport for a boosted Mazda race car $250+ for 30 lb boost
system for Subaru WRX is 250-500 buck for a boosted car.
You have way to much money tied up in this nice new engine to go and hurt it with a 25 dollar catch can.

 

[Chuck Leeper]

Fill yours with stainless steel scouring pads from the dollar store. The ones that look like a continuous spring wound into a ball,

AKA: Chore Girl.

 

[MikeS]

Some parts I’ll spend top dollar on, but We’re not splitting atoms here, it’s a catch can. If it’s plumbed as I described, it won’t matter if you’re running 30lbs of boost or 300, the can is under a constant state of vacuum.

 

[T- Type Tim]

So long as the can and fittings are sealed properly

 

[TurboTnZ06]

I had so much vacuum cruising I had to shove a restrictor into into the catch can to reduce the dia of the engine intake side line. Otherwise it'd suck enough oil in 30 minutes of driving to fill the catch can using a working GM pcv valve, which also acts as the check valve to not boost the crankcase.

 

[BEATAV8]

I keep it simple…..
Free flowing / low restriction breathers, one on each valve cover.
Stock PCV with a cheap check valve added in line.
No catch cans for me.

 

[T- Type Tim]

That’s what I have evolved back to as well

 

[Pronto]

Don't trust cheap check valves. I used the plastic ones for years and found out the flap had melted and it was doing nothing. I have since gone to a real check valve that does the job. UPR Pro Series™ Billet Check Valve - 0psi Cracking 0-100psi Operating Pressure

 

[daredevil95]

I appreciate all the advice, I'm going to try this setup today; stock PCV in intake, hose going to closed/baffled catch can with a metal check valve.....then catch can out line with another check valve going to turbo intake tube connected to brass 90 degree 1/4 fitting. probably only need one check valve but, gonna try 2 and see what happens? I'm hoping to start motor for first time tomorrow and break in new cam. So, we'll see how it goes today? The new headers don't sit the turbo in the stock location so, I have to chop up my turbo intake tube and fabricate a CAI, basically it's to long and the previous setup with new headers slams the filter into the fender, I bought a bunch of stuff to make what I got work. It will be painted and look good when done. Wish me luck....

 

[Pronto]

You only need one check valve. The PCV line should go from the PCV to catch can to check valve to intake vacuum source. The turbo inlet will not have enough vacuum at low rpm. You can have a line from the valve cover to the turbo inlet similar to the stock set up to help with crank case evacuation under boost. A oil separator could be in that line too. There are many theories on this. On the Corvette Forum, there is a member Kingtal0n that has a many posts on how the PCV system works and what the vacuum a needs are for the PCV and before turbo inlet for engine evac under pressure.
Another theory on oil in the PCV line I've heard is oil from the turbo return line getting on top of the intake bathtub gasket and running to the back of the engine is getting sucked up in the PCV valve. Don't know if that one is possible or not.