Catch Cans with Breathers

[69Mach1-409]

Yup, I edited the previous post.

I can see & smell them working, just don't have anything showing up when I wipe the area down. Bone stock motor, maybe I just don't beat on her enough? ..though I'd think if they were going to leave redisue, it would of been hot lapping at Import vs Domestic - Etown.

 

[jodadejss06gt]

If you want to do that you have to run a closed catch can style. You can't run an open breather style with a vacuum source, as stated you would be adding unmetered air into the engine.


Earl

Air/Oil Separator does not equal breather catch can. He originally was talking breather can. If he meant catch then he would not introduce unmetered. If he had a breather catch do those even have a line to draw vacuum?

How do you have yours setup. I still don't know what to do with mine

 

[G.T]

okay just to clarify, i'm not that stupid

my first and last post do not describe the same system, but rather two different options i'm considering:

i originally wanted an open breather catch can where the ports on the intake manifold and the intake elbow will be capped, then the PCV from each side is attached to the catch can with a breather.

now i think a more sane choice (given all the conflicting opinions) is to T both the driver side and passenger side PCVs into an air/oil separator, and attach that to the intake manifold port, while capping the port left open on the intake elbow (thus no leaks/un-metered air going in)

as for whether i'm concerned about blow-by reducing my octane rating on a supercharged engine, well sure i am.. but the blow-by on my particular setup is pretty little, but it's still gunking up the throttlebody over time, which is what got me looking into this in the first place

 

[jodadejss06gt]

Sounds good! On a closed loop setup most blow by is out the driver cover while on a vented setup its out the pass side. I'm hoping I have sucess with my breathers and no dripping oil.

 

[SteveP]

does it matter?
i see it as two lines going into a canister with breathers on top! seems to fit the requirement!

eitherway, as i said above, i think i'll plumb both lines from the driver and passenger side into one (large enough) air/oil separator, and connect that to the intake manifold port behind the throttle-body

price and flow of air

 

[RED09GT]

now i think a more sane choice (given all the conflicting opinions) is to T both the driver side and passenger side PCVs into an air/oil separator, and attach that to the intake manifold port, while capping the port left open on the intake elbow (thus no leaks/un-metered air going in)

You'd have both sides under vacuum setting it up that way. It would constantly be sucking without any source of air entering the system-not good. Usually this will cause a blown gasket as air will have to come from somewhere-that is where you will get unmetered air, and an oil leak to boot.
As it works on a stock car:
1. Fresh air enters the system in the tube before the throttle body
2. Goes from that tube into the passenger side valve cover,
through the crankcase to the PCV valve on the driver's side
3. Exits from the PCV valve on the driver's side through the hose into the intake manifold-after the throttle body.

The goal of the system is to vent excess crankcase pressure without the emmisions from an open style ststem.

Realistically, these are the best options for dealing with it:
1. Catch can on driver's side only
2. Breathers on valve covers (and oil cap is advisable) and cap off the intake ports
3. Catch can on both driver's side and passenger side (in theory, this shouldn't be needed but in some positive displacement superchargers, they seem to suck oil in before the throttle body as well).
4. breather-style Catch can attached to both valve covers-with both intake ports capped.

Option 4 is my choice.

 

[19COBRA93]

You'd have both sides under vacuum setting it up that way. It would constantly be sucking without any source of air entering the system-not good. Usually this will cause a blown gasket as air will have to come from somewhere-that is where you will get unmetered air, and an oil leak to boot.

Not exactly correct. Both sides under vacuum is actually the best thing to have. It can free up a considerable amount of hp as well as eliminate unwanted crankcase pressure. It also helps with piston ring seal.

An ideal setup is a vacuum pump connected to both valve covers with a catch can inbetween.

Crankcase vacuum = Good.
Crankcase pressure = Bad.

 

[RED09GT]

Not exactly correct. Both sides under vacuum is actually the best thing to have. It can free up a considerable amount of hp as well as eliminate unwanted crankcase pressure. It also helps with piston ring seal.

An ideal setup is a vacuum pump connected to both valve covers with a catch can inbetween.

Crankcase vacuum = Good.
Crankcase pressure = Bad.

On my fox mustang, I tried a catch can hooked to a vacuum source on my intake and went between pulling the pan gasket in and sucking in the rear seal. A set of breathers solved all problems.
I'm not sure why it kept happening especially after reading all this stuff on vacuum pumps-my only reasoning is that I drove the car daily and a lot of high vacuum highway miles as opposed to having a pump that speeds up with RPM so it could possibly provide less vacuum at a cruising speed than what the manifold would pull. I do agree that a vacuum pump would be the most ideal as it would provide vacuum when it would be the most useful to the system.

 

[retfr8flyr]

Air/Oil Separator does not equal breather catch can. He originally was talking breather can. If he meant catch then he would not introduce unmetered. If he had a breather catch do those even have a line to draw vacuum?

How do you have yours setup. I still don't know what to do with mine

I run mine with a breather instead of the oil cap and driver and passenger side run to a single breather can.


Earl

 

[jodadejss06gt]

Well I just took off the pcv valve stuff now and put breathers on tonight. I'm hoping I don't get a bunch of dripping. If so, I may try to get the oil cap breather.

 

[05stroker]

Not exactly correct. Both sides under vacuum is actually the best thing to have. It can free up a considerable amount of hp as well as eliminate unwanted crankcase pressure. It also helps with piston ring seal.

An ideal setup is a vacuum pump connected to both valve covers with a catch can inbetween.

Crankcase vacuum = Good.
Crankcase pressure = Bad.

Exactly, I have set mine up with a line from each valve cover going to two Moroso catch cans with breathers on the pass side frame rail behind the bumper , along with two lines from the valve covers going to a crankcase evac setup in the exhaust after the 02 sensors. The evac setup will pull a vac. on the crankcase under WOT and the breathers will take up the slack the rest of the time . Maybe not the best setup for a DD , but one that should work for me .

I feel on a low boost DD that a breather can setup with both valve covers plumbed to a single can would be fine . If you are pushing more boost then , one should really look at gutting the drivers side PCV valve . It is only about 3/16 dia. with the PCV valve in there , even though the nipple is larger then the pass. side , the pass side will flow more .

 

[G.T]

so i guess we'll all agree to disagree with each one having a solution that works for them, and everyone else saying it shouldn't work?