Breathers & Catch Cans Affect of Vacuum, Oil Pressure and Oil Flow in FI Applications

[Falkinman]

My mistake, I got it backwards, that's what I get for reading so much in one night LOL.

Either way, blow-by is a result of pressure, and pressure in the crankcase is a result of blow-by.

Ok now you're getting it. Just take it a step further.... I'm order to relieve the crank case of the pressure caused by blow by you need an evacuation system of some sort (PCV). And to take THAT a step further you need to create even more vacuum in the crank case to help the rings seal better for less blow by and more horsepower. Don't be so quick to tell someone that THEY are misinformed when its actually you!

 

[zeroescape]

How bout running something like this and route with a regulator and oil air sep.
http://shop.aerospacecomponents.com/vacuumpump3-vanebare.aspx

I think ive seen electric ones even.

 

[5.0_]

Would breather filters on the valve side and caps on the manifold be bad? The pressure still vents and the vacuum is capped off. NA

 

[07TGGT]

Nope, plenty of guys are running breathers. There is the argument of having no vacuum to help ring seal but it doesn't seem to be an issue

 

[Eel Mit]

Nope, plenty of guys are running breathers. There is the argument of having no vacuum to help ring seal but it doesn't seem to be an issue

Ring seal is helped by reducing the pressure on the crankcase side of the rings, allowing the combustion chamber pressures to push the rings outward into the cylinder wall to aid the seal and scrape off excess oil. Look into "gas ported pistons" for a further enhancement of this sealing.

The other thing I haven't seen mentioned in this thread is windage and its effects. By keeping the crankcase in a vacuum ( via a PCV or vacuum pump system) the oil cloud that is swirling like a tornado around the crankshaft (remember the oil is running down the inside of the block like a rainstorm from the heads and cylinder walls), now has to fall out of suspension and into the pan because there is no atmosphere to keep it whipped up. This separation can be helped by windage trays and extending the oil drain tubes from the heads farther down into the pan. There are some good videos of oil pans with lexan windows in them that show the sh*tstorm of oil.

1) Aerated oil doesn't lubricate well
2) Oil that is not in the pan can't be used by the oil pump, effectively reducing oil volume in the motor just when it is needed most.
3) That swirling cloud of oil is causing a load that the crankshaft is trying to cut through, almost like running an AC compressor ( which just transfers its load to the belts on the front of the engine). This is one reason many high RPM engines use knife-edged cranks.

Hope this helps!

 

[BV600]

Old thread but here I my catch can setup.

 

[onebadgsx]

I'll just leave this right here.

is anyone selling a kit like this. i wanna try one of these out.

 

[07TGGT]

PM me. I've been thinking about selling mine. It's ready to go.

 

[zquez]

is anyone selling a kit like this. i wanna try one of these out.

PM me. I've been thinking about selling mine. It's ready to go.

If you don't end up getting his, they're pretty easy to piece together for not too much. I don't remember what I paid, but I'm pretty sure it was nowhere near what I could buy a kit for. The big cost variable is what hose you get and where from.

 

[Sharad]

Unfortunately, I installed the catch can on my car right before I installed the blower, but I can tell you it's disturbing how much oil/water vapor it catches. I'm in South Florida, so maybe the humidity plays a role. But I'd think the vaccuum from the blower inlet affects it too. (the ProCharger draws more vaccuum at part throttle than the engine, that's why the blow off valve is constantly hissing) The UPR can catches A LOT of oil. I can fill the 7oz can in 2000 miles.