so on the two top fittings of the catch can, they both goto the back of the block

 

Almost. Top two fittings go to the back of the block where crank case pressure is highest mainly at cold start and where oil pressure is at peak. Valve cover w/ check valve goes to Intake manifold front vacuum port. Crankcase issues are rarely at the valve cover baffles contrary to popular opinion.

Bottom port drains back to the block as you stated.

Not one puff of smoke, not one saturated canister filter.

 

Thanks for the detailed post Wish I had this a month ago lol. Just paid to have valve cover welded up.

I have the same can mounted in the same location already

 

The welded valve cover stuff got popular with many IFO and other rules about 8 years back.. People saw it, and had to make their street cars look like it..

I change valve covers on a regular basis. So I don't like to ruin them by using weld bungs there.. Just one more potential place for oil to leak

 

Yea Im realising it would be nice to have a cut VC for cam gears just for when I go in for tunning other then that I prefer not to use one that has been cut

 

That's sort of what I meant by 3 breathers. Forgive the vintage 2004 picture with the primitive artwork, but it was the only one I could find. So, the bottom of the catch can drain back is connected to where the stock black box used to be that most people plug (blue square), and crankcase pressure doesn't blow through that? Does the valve cover breather with the check valve in-between connect to the area in the top right (red square) that also normally gets plugged?

 

you have everything right except for the last part. the check valve replaces the PCV valve completely, and nothing goes to the upper right corner. Picture 3 shows in the background how the check valve hose goes from valve cover, snakes around the intake manifold and connects right at the front part of the intake manifold underneath the "SKUNK2 PRO" badge.

 

Just saw one a few of my old posts got quoted... That would still be my recommendation, but I'll add more details

The Toyota PCV valve (any PCV valve meant for a turbo Toyota -- Supra / MR2) is designed to be 100% sealed under boost, but allows circulation flow during vacuum. The Supra NA or IS300 valve also works and tested well under boost, and minor grinding and you can fit it directly onto the stock Honda OEM PCV blackbox. This basically prevents any condensation building in your valve covers (especially when running a vented catchcan) or any unwanted fumes during idle/cruising.

I would not use the exhaust evacuation setup. The check valves have really short lifespan, and it is not meant to take long trips or sustained high heat. They are meant for race cars preferably with open downpipe or a megaphone shortly after the check valve. When the check valve gets stuck which will happen eventually, it can create a lot of problems (blown valvecover/oil pan gaskets, turbo smoking, etc..). Only the Moroso check valves strictly designed for crankcase ventilation can be used. If you use other types of check valves like the Vibrant one, or other similar valves, their cracking pressure is already too high and the crankcase won't vent properly at all. If you don't run any check valves, you must be fully open exhaust with no cat / resonator and basically no possible way for exhaust to build ANY pressure before considering this setup.

For street cars, I still have two openings with welded bungs on the valve cover routed to a nice baffled catch can. I only use one of the rear block fittings as a drain back, and on some cars, I actually weld a steel -8AN bung onto the OEM black box and use that as a drain. The outlet lines can have breather filters on them, or routed back into the turbo inlet. If you are running the line back into the turbo inlet, make sure you run a nice big line if you want the vacuum assist to work. I usually have a -12AN single line or dual -10AN line if I routed back into the turbo inlet.

It may appear that if you run a vented catch can with breather filters, you will have unwanted oil fumes in the engine bay (and eventually entering the cabin when sitting in traffic). That won't be the case if you still have the factory PCV black box + PCV valve. During idle or cruising, the vacuum pulling from the intake manifold will always keep a slight vacuum inside the catch can so no fumes actually make it out the catch can at all during idle or cruising. So it's simply preference if you want to run open breather filters or route the line back into the turbo inlet.

 

I see it now. That picture confused me, because you didn't take a more direct route between the valve cover and intake manifold vacuum. You're still sucking all that gunk into your intake manifold, though. Aside from that, how much do you smell the crankcase vapors, because it looks like a blingy version of an Endyn setup with a better drain back. I used to have one of those, and although I got used to it, sometimes I had to keep the vents on recirculate. I'm trying to get rid of the smell.

 

Interesting. Right now I have a T1 catch can with 2 hoses from the valve cover, and 2 from the back of the block with the black box removed and the hole behind it plugged. If I reinstall the black box with a PCV valve back in there this would help with the smell? By the way, I use the original PCV vacuum source for a vacuum manifold block. If the hose is big enough, could I connect the PCV to the vacuum manifold?

 

Thanks tony.....

Today I setup my black box as a vented/drain back system. Basically hooked up like stock only difference is i Installed a filter instead of a PCV valve (never seen this done but I dont see why not). I also have a vented can going to my VC

I was planning on this:
stock catch can vented/drain back
aftermarket catch can venting the 2 VC ports
Vacuum assist on stock VC nipple

Still on the fence between running vacuum to the black box vs vacuum to the VC. Dont really want My IM seeing to much oil. At this point I still have the ability to go either way

 

See, I get no smell at all with the Black box as a drain back, and nothing on the valve covers.. just the back of the block using the S80 Check valve (a nicer version of the OEM PCV valve at the IM).

No smells or residue of any kind.

 

that's why the check valve. My IM is clean as a whistle. valvecover to the IM w/ check valve. And I go from about 17psi-26psi on a regular basis.

 

Yea but the factory PCV system seems to pull oil from the black box (pcv valve is basically same as a check valve) ....this is why I am leaning twards vacuum on valve cover rather then black box

 

Basically ain't the same..

But I've used stock PCV for over 300whp for years, no issues..

400whp+ now I change it

 

How long does the check valve hold up for?

 

It's an OEM part... So far I've seen the same one used for about 18 years.. Kinda don't need to keep track of it.. Once it's on, it works forever

Long enough for ya? :-)

 

Sounds good. I might give this way a try

Wait, I don't have the black box (B18b) damnit

 

You don't need it. I'm talking my method. I have no idea about the other "black box" method. I either used this method or left the stock PCV system completely intact.

 

I think you are a bit unsure of how the PCV system gets vented and the direction of flow it takes The PCV valve works by supplying vacuum if it is hooked up to the intake manifold in a regulated manner (it has a small orifice). The PCV valve only sucks during light throttle/idle but it would act as a check valve and prevent flow in the other direction. When you are under boost (or 0-vac), the valve will seal against any boost from the intake manifold. I recommended a Toyota PCV valve because the OEM Honda one is known to slightly leak boost into the blackbox. The Toyota one is 100% sealed, and can take lots of boost.

When the PCV valve is sealed under boost, then the only means of venting the crankcase is by the valve cover ports and out the catch can setup.

You do not want to hook up straight vacuum into the stock valve cover vent port because it is unregulated. Doing that will create a massive internal vacuum leak which will mess up your idle and engine vacuum. Without a PCV valve or check valve, it will also send boost into the crankcase and become a boost leak out your catch can. In order to create a slight vacuum for your crankcase is to have a functioning PCV valve connected from your blackbox and into the intake manifold. The PCV valve only allows a small amount of vacuum flow, usually equivalent to about 100-150 RPM of idle increase which is normal.

On your picture above, by placing a breather filter onto the blackbox will make it into fully vented system. It's no big deal because it is just another place to vent; however, because the blackbox is actually located at a very low spot on the engine as well as being located at the main oil return gallery of the block, it will always build pressure first and have the highest pressure zone. Being at such a low spot + big oil return gallery for the cylinder head/block + breather filter, it will shoot tons of oil right out of the breather and make a huge mess.

Catch cans are always mounted high up in the engine bay for this reason. So my suggestion is to plug up the blackbox and remove the breather filter. If you are not using a PCV valve (if you won't want any oil at the IM for cleanliness), then just use the blackbox as the oil catch can drain. If you already have the rear block port fittings hooked up to your aftermarket catch can anyway, then you can remove the blackbox altogether if you just want a full vented system. The ONLY reason to keep the factory black box is to keep the PCV valve in plate for slight vacuum pull during idle and cruising.

For crankcase vacuum assist under heavy throttle and under boost, then you can choose to hook up the catchcan vent lines into the turbo inlet. Don't get mixed up between vacuum assist during idle, versus vacuum assist during WOT!

 

LS's had them

 

Yup, by doing that will eliminate the fumes when you are sitting in traffic. That would be a perfect setup because you still have one port at the back of the block for proper drainage, and you have well enough ports for venting under boost.

If you want to prevent any oil from entering your vacuum log and contaminating any components like MAP sensor / boost solenoids / etc... you should hook up the PCV directly to the intake manifold. But hooking up to the vacuum manifold is totally fine in terms of function.

 

Actually I had a pretty good Idea about most of this. I wasnt sure if my black box would possibly spew oil.....I will change this since its less then Ideal

I had no intention of doing this, I was going to use Theshodans example of using the volvo check valve

My aftermarket Catch can is not setup as a drainback at the moment, I will keep an eye on it, if its filling up too fast I will need to get a drainback system

I am not too concerned about vacuum assist at WOT, Im fine with My vented aftermarket catch can (the same one the shodan is using only difference is no drainback), I was only worried about vacuum at idle


Thankyou for the reply it was very helpful

 

Only OBD1

 

Im still confused on how this whole damn thing works.

Valve cover -> black box
Black box -> check valve -> intake
Black box -> block as drain

Is that it?