I'm extremely interested in this as well. I've been going back and forth about what to do about my catch can setup.

Could one just run the 2 VC breather ports to a tee, and the 3rd line off the tee to the exhaust, eliminating the catch can all-together?

Its actually an aerodynamic effect more then a ring seal effect. The amount of pressure in the cylinder is over a 100 times higher then the few pounds of - pressure created by the vacuum.

By reducing the pressure in the crank case reduces this reduces the air density in the crank case. So following from aerodynamic drag density is a proportional scalar of this drag. So if you reduce the pressure in the crank case to 20% of normal, then aerodyanmic drag will be 20% of what is normally experienced.

http://upload.wikimedia.org/math/9/9...7b238e5de9.png


This system combined with crank scrapers could do an excellent job to improve efficiency and get extra horsepower out of the engine.

I don't see any problem with the system from a reliability standpoint either as the intake manifold regularly pulls the crank case pressure down, this just does it on a larger scale and at loads that matter as far as horsepower is concerned. The actual effect seen here is the bournulli effect.

http://en.wikipedia.org/wiki/Bernoulli_effect

Using the equations here you could probably round about estimate an optimal pipe size to exhaust flow velocity to get suction sucking.

If you’re venting the crank case to atmosphere the cat is pretty much pointless anyway in terms of emissions because you’re creating emissions that don’t go through the cat.

And I don’t understand why it would make much difference where along the exhaust system you put it as long as you didn’t put it in before a restriction. The exhaust flow has the same mass flow rate along the entire distance it losses a small amount of velocity as it cools but it can't be much.

Bob

Ditto and same question. I'm contemplating if I want to run this with my catless 3" exhaust and wondering where the optimal place to mount it on the DP.

Won't pass emission venting to atmos- so the cc vent goes intake preturbo.
I guess the location being at the front was in reference to burning the mix and the impact on efficiency of the length of tube carrying that mix.

I don’t think it would be good to eliminate the catch can it is needed to separate some oil. I've never been able to keep lots of liquid oil from filling up my catch can due to certain cornering/acceleration conditions I seem to see on a lot of tracks. Never a problem on the street though. I don’t mind some blow by going out the tail pipe but I think dumping a cup of oil out in the exhaust every so often would look sort of bad.

Bob

I'm worried about the ability of the cat to pass the expelled contents of the crankcase without eating itself apart. I don't plan to pass emissions testing, but the cat is staying in. This is a 99.9% street car, I care at least some for emissions components - enough to not run a crankcase vent to the exhaust if it means removing the cat.

Somehow I don’t see how the flow rate would be high enough for the line length to be much of an issue.

I’m actually thinking of putting the slash tube in my test pipe where the cat would be and have the components so I could quickly convert my catch tank system into a PCV emissions legal closed system.

Bob

I would think the vent would have to be after the cat or anything else restrictive in the exhaust to be effective.

Bob

Divided into subcomponents - these are 2oz (to the rim of the glass) shot glasses.

The middle third doesn't subdivide very readily, and I don't have a centrifuge, so that's as fine of detail as I'm going to get.

Enjoy!

Attachment 191434

The middle third adheres to the glass, which further increases the difficulty of separating it. You can see where it has adhered to the water glass on the right during separation.

Bottoms up.

LOL, that was one of my first thoughts!

I've been using one of the Summit slash cut/check valve evacuation kits on my old GTO for years. It works well in the header collector. If you drop the breather hose in a gallon jug of water it will suck it dry in just a couple of good jabs on the throttle. You will want to disconnect it if you put your car on a dyno because it will cause the tailpipe o2 sniffer to read incorrectly. And it is better to use it in conjunction with a catch can so that all of that oil doesn't end up in your exhaust (makes a little smoke).

What check valve is that? I am not finding it on summit.

So the routing would be like this?

Valve cover only routed to catch can
catch can VTA
and
catch can also routed to exhaust slash cut.

Or is the VTA in the catch can not necessary?

Jagermeister, Baileys, and Miller Light :X

It wouldn't interfere with a regular WB02 sensor downstream though would it?

Yes, I'm pretty sure it would.

Also, if one had a restrictive exhaust, this wouldn't work as well.

I found a one way valve at summit:

http://www.jegs.com/i/JEGS-Performan...93#moreDetails

It would be nice to find one with threads so I could run AN fittings and braided line instead of something that will wear out.

I thinking having a VTA on the can would defeat the purpose of trying to create a vacuum on the head.

Search for my thread with "tiny hole" in title.

The drain passages are huge compared to the hole I enlarged in the cam cover, and compared to the 1/2" hose and fittings I used.