I run the header evac setups on all the chevy builds that I've done over the years. We put one on a turbo'd mustang once in place of a catch can setup and it would go through oil rather quickly, guess it sucked too well. Just one example for what it's worth.

well to add another 0.02 with my crankcase pressure, i intermittenly have a dipstick pop up and when i mean pop maybe a couple inches out of the tube. now with my cusco, ive been running my mods for 14k miles on my built engine, and almost 10k prior on stock engine with my cusco oil catch can, now on my can i have a hose next to it, that basically monitors how much oil vapors is currently in the can kinda like a full marker...to this day 3 years later still cant even see it registering on the full marker.. so imo try a cusco granted its a couple hundred for it, but if it helps alleviate some headaches your havin, then there ya go. hahah
good luck
dastallion out

Pre-turbo has a vacuum under boost. The vacuum pulls the gas through the catch can from the crankcase into the intake pipe which then gets burned. Just like how its set up from the factory only adding a catch can in between. Most evo guys cant seem to grasp the concept, but the DSM guys figured it out a while ago. Probably cause the DSMs are all older and have more blow-by problems...but eventually evo guys will get there. :P

What size AN fittings did you install on the valvecover?

here is what I ended up doing, I copied and pasted in here for you to look at

the thread is located here is you choose to see more

"Good morning everyone,

A little while ago, I had some ideas about positive crank case ventilation, in which I wanted to relieve as much pressure as possible, but still retain the PCV system for daily driving benefits.
I had intially come up with the following sketch
Attachment 290573

Now it was time to put it all together.
A while ago I had rex powdercoat a valve cover for me, as I was tired of the red stock cover. I also drilled out the sides of the cover, so that I would be able to place -10 AN lines to it. These relief holes are above the baffle plate that is in the stock evolution V.C
here is what the cover looks like
Attachment 290574
a picture with the 1/2"NPT to -10AN fittings installed.
Attachment 290575

Realestate under the hood of my car is very limited. The catch can that I have is rather large, so I definitely had to get creative with a location for placement. I decided that I would place it infront of the transmission an under the intake pipe. I ended up using an old saw zaw BLADE, bending it up and creating a bracket to hold the catch can
Attachment 290576
Attachment 290577
here is what it looks like under the intake (you can barely see it )
Attachment 290578

Oh I almost forgot, I made this intake completely out of straight pieces of 4" stainless pipe. However the guy that tigged it up, did a terrible job, where I had to spend about 4 hours, grinding everything inside the pipe down, because of all the slag that was present. Rex, then finished her off with some black chrome powder coat. I think it looks really nice now, you can't even tell that it was pipe cut
Attachment 290579

Moving along, I began to take off the old cover, transferring gaskets,pcv valve, and the little washers that go under the V.C bolts
Attachment 290580
if you look in this picture you can see the air oil separater which is by the oil dipstick in the left side of the picture below
http://i2.photobucket.com/albums/y23...o/DSC00667.jpg

I added my -10 AN Prolite hose, to the 45 degree -10 an fittings, definitely gives it a nice contrast
Attachment 290581

installing the cover
Attachment 290582

here is a picture of the can without the filter and with the hoses attached
Attachment 290583
Attachment 290584

and finally with everything together
Attachment 290585
Attachment 290586
Attachment 290587

here is the finished product, sorry but the GF was taking way too many pictures, so I am posting them all up :)
Attachment 290588
Attachment 290589
Attachment 290590

Attachment 290591

and finally with the hood closed
Attachment 290592

Hope you enjoyed my sunday afternoon work.

have a great week everyone
later

Do i see 2 bov's?

ya hes got 2 bov's. i was gonna do exactly what he did with the valve cover but JID told me not to do it because it will dump to much oil into the can..... now i am interested in knowing how much oil you see in your breather tank antilag?

Tscompusa ........ feel free to call me warren :)

In the oil separator the one that is between the PCV valve and intake manifold I see maybe 2 table spoons of oil, In the main catch can that has the two -10 an lines going to it, I see a minimal amount of oil/water condensation. When I say minimal, a few drops here and there, The car is driven approximately 80 miles daily, with a few mash it to floor escapades.

I hope that helps and feel free to ask any questions, and I will do my best to help.

Edit : IT WILL dump oil if you drill the holes, below the baffle of the valve cover, IN my case, the two 1/2 inch NPT holes are above the baffle of the valve cover.

Ya mine is above the baffles also. I have no problems, I do not road race my car though, just quick burst to 150 :)

Creamo3, I use 1/2ntp to -10

Fathouse

Warren,
Where did you get your catchcan from? Baffled?

If your going to drill, then just go a head and fab a baffle for the extra port. The oem ports are protected by a baffle so oil spraying around doesnt reach them as easily, just the vapors.

Also one thing to keep in mind. If you are running 2-3 or more valve cover ports to a catch can that has only 1 X" or example 3/8" exit breather, then your setup defeats the purpose. Make sure you put a breather or multiple breathers to allow proper ventilation according to number of vacuum tubes and their size.

And I also noticed on some of the setups people are still recirculating back into the intake manifold. The valve cover does not need to have a vacuum source attached, its just their for emissions purpose. But if your running a catless exhaust, whats the point?

Here is a setup my engine builder suggested. This involves running two cans.

One can will be vented and come from the side cover port. The second will run from the back port into a second can and run in some where on the bottom. Keep the PCV on. Then run a line from the top of the can to the turbo intake. Inside the second can put some steel mesh inside.

This will allow you to vent pressure as well as keep oil and whatever **** is in it from circulating through the system. And you shouldn't have problems with oil all over the engine bay.

http://www.dsmtuners.com/forums/arti...cv-system.html is a good read


http://www.dsmtuners.com/forums/atta...4&d=1270504361

http://www.dsmtuners.com/forums/atta...5&d=1270504361

these 2 seem to be the best route for my setup. i think the max pressure relief and then just place a krank vent/ check valve such as http://www.usplastic.com/catalog/ite...6844&catid=489

or similar in between the pcv hose.

on a metered air setup for maf its recommended to dump them back into the air intake pipe rather then dump to atmosphere, plus it will get vacuum from the intake pipe, but i dont think it really matters if its blown to atmosphere. personally i like the atmosphere idea better, but it seems the extra vac produced from the turbo does assist in removal of gases from the crank cover.. so im debating what to do right now.

^^^holy crap thats a long read...good read though...

Subscribed. Good info