Crank Case Pressure, Catch Cans and Breathers
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From: Centrifugal City
Crank Case Pressure, Catch Cans and Breathers Is there any advantage to running a catch can with a breather setup vs. breather alone?
I've seen some people that are very happy using an oil separator/catch can with a filter/breather on top. Like a Jaz setup.
Other than not smelling vapors, is there an advantage? I've heard some hook up a drain that can drain back to the oil pan. Is this possible without pressurizing the catch can? Add a check valve and drain the caught oil back to the motor?
Is the only advantage catching the oil and keeping the oil from blowing into the engine bay or underside of the car? And keeping the vapor smell down?
If you have to empty the catch can by hand it'd be a pain. Have also heard of 'vented' catch cans and not sure what that means vs. breather.
Just thinking of all options..
LPE seems to be using this on their Turbo cars:
http://www.lingenfelter.com/Merchant...egory_Code=P09
I've seen some people that are very happy using an oil separator/catch can with a filter/breather on top. Like a Jaz setup.
Other than not smelling vapors, is there an advantage? I've heard some hook up a drain that can drain back to the oil pan. Is this possible without pressurizing the catch can? Add a check valve and drain the caught oil back to the motor?
Is the only advantage catching the oil and keeping the oil from blowing into the engine bay or underside of the car? And keeping the vapor smell down?
If you have to empty the catch can by hand it'd be a pain. Have also heard of 'vented' catch cans and not sure what that means vs. breather.
Just thinking of all options..
LPE seems to be using this on their Turbo cars:
http://www.lingenfelter.com/Merchant...egory_Code=P09
Last edited by MelloYellow; Apr 4, 2005 at 12:39 AM.
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From: Norn Iron
As long as the drain is placed below the oil level, it will work fine. it means you can have an effective breather system, where you never need to manually drain a catch tank, or oil is lost via the breathers. All oil blown out, shoud be caught, and fed back into the system ia the breather/catch tank.
If the tank is effective enough so that all oil/oil mist is caught in the breather tank, then you could vent the topside back into the intake again ( not inlet manifold, but intake before the TB ), without fear of oil being drawn in, for an emissions friendly setup.
If the tank is effective enough so that all oil/oil mist is caught in the breather tank, then you could vent the topside back into the intake again ( not inlet manifold, but intake before the TB ), without fear of oil being drawn in, for an emissions friendly setup.
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From: Centrifugal City
A very good discussion on the Corvette Forum.
Best info is on 2nd page of thread.
Cross-referencing:
http://forums.corvetteforum.com/show...8&page=2&pp=20
Best info is on 2nd page of thread.
Cross-referencing:
http://forums.corvetteforum.com/show...8&page=2&pp=20
Last edited by MelloYellow; Apr 4, 2005 at 06:22 AM.
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From: Centrifugal City
Ya, kinda lame.
I'm going with a nicer Jaz catch can @ $53 via JEGs.
The Corvette Forum thread above has much better info.
This thread here hasn't been moving as much.
The idea of draining back the catch can to the oil pan is interesting tho. Haven't seen anyone do that before which is why I linked to it.
P.S. Another reason to switch from plain breathers to a catch can/breather is so you don't dump oil on the track. If track officials see a plain breather don't they get upset?
I'm going with a nicer Jaz catch can @ $53 via JEGs.
The Corvette Forum thread above has much better info.
This thread here hasn't been moving as much.
The idea of draining back the catch can to the oil pan is interesting tho. Haven't seen anyone do that before which is why I linked to it.
P.S. Another reason to switch from plain breathers to a catch can/breather is so you don't dump oil on the track. If track officials see a plain breather don't they get upset?
Last edited by MelloYellow; Apr 4, 2005 at 06:16 AM.
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From: Centrifugal City
Originally Posted by stevieturbo
As long as the drain is placed below the oil level, it will work fine. it means you can have an effective breather system, where you never need to manually drain a catch tank, or oil is lost via the breathers. All oil blown out, shoud be caught, and fed back into the system ia the breather/catch tank.
im not sure i would want to drain that liquid back into the engine, on my setup, vented catchcan, the liquid in the can wasnt like an straight oil, seemed like a very thin oil, more like water.
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From: Norn Iron
Any water/condensation deposits will burn off when re-introduced to the sump. ANd you get moisture and condensation inside the engine at times anyway..some of which is getting blown out the breathers too.
The only real thing that will be returned via the drain on the bottom of the catch can, is the oil that has been blown out and into it in the first place..
The only real thing that will be returned via the drain on the bottom of the catch can, is the oil that has been blown out and into it in the first place..
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My LT1 STS PCV set up Hear are a few pics of my current set up. I think I still need a catch can. I wish that LPE unit wasent so expensive! I like the desighn~!
I installed a Check valve in the PCV line and the other side has a scavanging system to the exaust with a check valve in the other direction!
I installed a Check valve in the PCV line and the other side has a scavanging system to the exaust with a check valve in the other direction!
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From: Centrifugal City
Am going to do a leak down on 5,6,7,8 tomorrow. Cap off the PCV system completely.
I'm getting blowby oil out the Passenger Valve Cover breather, but none out the driver side. I'm thinking of capping off the Passenger valve cover completely and running the LS6 valley crankcase nub and rear driver side valvecover nub to my Jaz Catchcan.
Can anyone comment on blocking the Passenger side? The poor baffling inside the pass. valvecover might be contributing to the blowby somehow. Just thinking.. I don't get a drop out of the driver side breather, only the passenger side.
I'm getting blowby oil out the Passenger Valve Cover breather, but none out the driver side. I'm thinking of capping off the Passenger valve cover completely and running the LS6 valley crankcase nub and rear driver side valvecover nub to my Jaz Catchcan.
Can anyone comment on blocking the Passenger side? The poor baffling inside the pass. valvecover might be contributing to the blowby somehow. Just thinking.. I don't get a drop out of the driver side breather, only the passenger side.
I have one of those small Jaz cans on the workbench.
Recirculating the oil sounds nice, if it's not too hard. Would it need to be mounted high in order for gravity to feed it back to say a valve cover?
I am not going to bother, I will continue to run dual breathers. I just got another 99-02 passenger side valve cover to mount on the driver's side so I can run the big breather on each side.
Recirculating the oil sounds nice, if it's not too hard. Would it need to be mounted high in order for gravity to feed it back to say a valve cover?
I am not going to bother, I will continue to run dual breathers. I just got another 99-02 passenger side valve cover to mount on the driver's side so I can run the big breather on each side.
Originally Posted by Pro Stock John
I have one of those small Jaz cans on the workbench.
Recirculating the oil sounds nice, if it's not too hard. Would it need to be mounted high in order for gravity to feed it back to say a valve cover?
I am not going to bother, I will continue to run dual breathers. I just got another 99-02 passenger side valve cover to mount on the driver's side so I can run the big breather on each side.
Recirculating the oil sounds nice, if it's not too hard. Would it need to be mounted high in order for gravity to feed it back to say a valve cover?
I am not going to bother, I will continue to run dual breathers. I just got another 99-02 passenger side valve cover to mount on the driver's side so I can run the big breather on each side.
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From: Norn Iron
If running a closed system, whereby teh oil caught is re-entered to the engine, the drain from the catch tank to the engine, must enter the engine below the oil level.
If you attach it anywhere above the oil level ), it will try and act as another breather outlet.
If its below the oil level, there isnt enough air pressure in the crankcase to blow the sump oil out the pipe, but it allows oil in teh catch tank to drain back into the sump.
The catch tank could be mounted anywhere, as long as the oil drain is higher than sump oil level, so gravity will drain it back into teh sump.
If you attach it anywhere above the oil level ), it will try and act as another breather outlet.
If its below the oil level, there isnt enough air pressure in the crankcase to blow the sump oil out the pipe, but it allows oil in teh catch tank to drain back into the sump.
The catch tank could be mounted anywhere, as long as the oil drain is higher than sump oil level, so gravity will drain it back into teh sump.
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From: Centrifugal City
Leak Down test results on my Forged Motor:
Tested Cyl 2,5,6,7,8. All were 6% leak down except one at 5%. Test was done at 104* engine oil temp. Compression test looked good also.
Am very happy with the results.
Guess I'm just dealing with normal blowby issues.
Track officials might not like breathers dripping oil on the track. I'm going to start with the manual catch can next. I tried cap'ing off the passenger valve cover nub tonight and running the LS6 valley cover nub to a breather instead. Also capped the PCV that had a McMaster check valve. Car did NOT like that setup at ALL. Lifters sounded awful. Whole motor sounded bad.
Rolled change back to normal with Check valve for PCV. Running to a catch can will keep the breather filters from getting clogged in oil and losing the ability to vent. Also will keep the oil contained and not spraying all over the bay or dripping under car.
Hopefully keep the oil vapor smell down a bit more also..
I think I'm blowing out 1 Quart every 500 right now.
Tested Cyl 2,5,6,7,8. All were 6% leak down except one at 5%. Test was done at 104* engine oil temp. Compression test looked good also.
Am very happy with the results.
Guess I'm just dealing with normal blowby issues.
Track officials might not like breathers dripping oil on the track. I'm going to start with the manual catch can next. I tried cap'ing off the passenger valve cover nub tonight and running the LS6 valley cover nub to a breather instead. Also capped the PCV that had a McMaster check valve. Car did NOT like that setup at ALL. Lifters sounded awful. Whole motor sounded bad.
Rolled change back to normal with Check valve for PCV. Running to a catch can will keep the breather filters from getting clogged in oil and losing the ability to vent. Also will keep the oil contained and not spraying all over the bay or dripping under car.
Hopefully keep the oil vapor smell down a bit more also..
I think I'm blowing out 1 Quart every 500 right now.
Sounds like you have a lot of blowby. Is it a loose motor?
My car has been a dyno queen for most of the last 5 months, but it has not been making a mess with oil misting out of the breathers.
I would like to run a seal catchcan system some day but I was not able to find fittings that would fit into the valve covers. My other passenger side cover just came in from Valvegod so I will swap that onto the driver's side so I can run the bigger TTi breather on that side too, and remove the small KN cheater filter I have on there.
My car has been a dyno queen for most of the last 5 months, but it has not been making a mess with oil misting out of the breathers.
I would like to run a seal catchcan system some day but I was not able to find fittings that would fit into the valve covers. My other passenger side cover just came in from Valvegod so I will swap that onto the driver's side so I can run the bigger TTi breather on that side too, and remove the small KN cheater filter I have on there.
Originally Posted by MECHAM
in the pics below..is one way better than the other?
the square box is a catch can
sry for the ms paint drawings
#1
#2
the square box is a catch can
sry for the ms paint drawings
#1
#2
Keith
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From: Centrifugal City
LOL guys, hilarious!
Wouldn't #2 catch oil more effectively and create more vacuum?
I was real happy with my leakdown #'s.
My bearings have seemed a bit loose and my oil pressure a bit low, but MTI and other MTI owners have said it's normal. Think loose bearings relate to increased blowby?
It's pretty easy to run 3/8" fuel line off the valve cover nubs to a breather or catch can solution located anywhere in the car.
I might be exaggerating and it could be 1 Quart every 1000 miles. I just definitely notice the oil level changing and breather leaking.
Wouldn't #2 catch oil more effectively and create more vacuum?
I was real happy with my leakdown #'s.
My bearings have seemed a bit loose and my oil pressure a bit low, but MTI and other MTI owners have said it's normal. Think loose bearings relate to increased blowby?
It's pretty easy to run 3/8" fuel line off the valve cover nubs to a breather or catch can solution located anywhere in the car.
I might be exaggerating and it could be 1 Quart every 1000 miles. I just definitely notice the oil level changing and breather leaking.
Last edited by MelloYellow; Apr 8, 2005 at 01:50 PM.