hvAlfaWant_S2000

Hello All,
I combed this forum (and the internets) for hours over many days and nights to find the easiest and cost effective strategy to catch oil getting sent out my BOV on my AP1 w/ vortech v2 with Tial BOV.

This is what I'm going to try first.

Keep the Supra PCV valve on the existing line to the intake, and then add a closed (not vented) Mishimoto Compact Baffled Oil Catch Can off the front valve cover outlet and output that to the vortech intake pipe (where the air filter is).

Does this sound feasible? I want to stop that oil from getting spit out of my BOV. Its spraying a fine mist all over the engine compartment.

Thoughts?

Btw, I'll be trying for about 12-15 psi when I upgrade my pulley to a 3.8".

Moddiction

Why would you not just cap off nipples on intake manifold and run a couple lines to a vented catch can. No reason other tha emissions to recirculate it. No chance of spraying oil into intake manifold. Run line from pcv and other vent spot or drill and weld on a couple larger ports.

hvAlfaWant_S2000

Thanks Mod.

So just block off both the intake nipple and the air intake hole on the air filter elbow?


I could then run both ports on the VC to a vented can. I was considering running a hose(w/ lil filter at end) out of the top of the can to place it lower in the engine compartment to avoid that oil vapor smell in the cabin.

Sound about right?

Moddiction

Yeah you can't recirculate the lines to intake manifold with a vented setup but only reason to route it back to the intake manifold is for emissions.

I would cap all intake manifold and intake arm nipples and then run the lines off the valve cover to a vented catch can setup.

hvAlfaWant_S2000

Sounds good mod. That's what I'll do.


Last question: my vented can has dedicated IN and OUT marked ports. Does the head push the fumes and oil in any particular direction?

Should the pcv line goto the IN port,etc?

Thanks allot.

rmerchant3

Disregard

hvAlfaWant_S2000

rmerchant3

Sorry I was confused on the setup you were trying to achieve.

The stock PCV works like this. The PCV valve is normally closed. When an engine is at idle the manifold is under vacuum. This line going from the intake manifold to the PCV valve applies this vacuum to the PCV valve opening it. The flow goes from the crankcase, through the valve, through the hose, and into the intake manifold. When the crankcase is under pressure (such as in a turbo or supercharged application due to blowby the rings) this can create excessive oil vapors to flow through the PCV into the intake manifold getting it oily inside.


RECIRCULATED:
So, the hoses go like this. (AP2) the PCV is threaded into the valve cover. Run a hose from the PCV valve into your catch can. Then from the catch can to the intake manifold. The flow is from the crankcase to the intake manifold. So keep the arrows in that direction.

OR

VENTED TO ATMOSPHERE
If you do not recirculate, (I believe you should to apply vacuum to the rings under idle) You would run a line from where the pcv valve was into the catchcan then out to a filter vented to atmosphere. The flow is in that direction

The flow direction doesn't change in either method, just where the flow goes.

hvAlfaWant_S2000

OK, so how about this dual setup?

Run a closed-loop(recirc) can from PCV to baffled can to intake, to apply vacuum to the rings under idle.

AND

Cap off the intake arm nipple and run a vented can for the breather tube (2nd port in VC) which will vent to the atmosphere.

Will things flow correctly under this situation? Will the closed loop line really apply the vacuum needed for the rings, while the other hose is set to vent to atmosphere?

Sorry for beating this to death, but I need this sorted before trying for 450+rwhp on Tuesday!

thanks all!

rmerchant3

You just described a dual catch can system. That is how I would do mine if I had the patience and the room. I vented my other port on the valve cover (the breather port) to atmosphere using a small breather filter. If I start to see any oil residue on that breather filter, I will take the time to catch can that line as well. Whatever you decide to do with that line it is recommended NOT to let it get it's filtered air from the intake tube. Under boost any blowby will find it's way out and it will be through that line. this will force oil out with it and can start to make your rubber connections from the charger to the intake slippery and can make them blow off under boost over time. Not to mention getting oil in the intake which is what you are trying to avoid in the first place. Radium makes a nice dual catch can system, but they are proud of it too. They make nice stuff, but geez.

As for vacuum on the rings making a difference. If you vent both sides to atmosphere, you have no help to get the pressure out. By keeping a closed loop system, the vacuum created inside the manifold helps to "pull" the gases out of the crankcase. Reduced pressure on the underside of the rings is less that the rotation of the crank has to fight. Now under boost, the PCV closes and you are strictly venting to atmosphere through the breather port on the valve cover, but as soon as you let off, that added suction from the PCV will greatly help get rid of the pressure.