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swartz
05-31-2004, 03:27 AM
can i hook up a hose from the valve cover to my intercooler pipes and put a check valve on it so when its under boost it doesnt get pressure but when its in vaccum it sucks pressure out the head? right now all i have is a breather filter on the valve cover.

also whats up with that tube with the spring that goes from the intake mani to the block when i boost doesnt that create pressure in my block thats bad

bimmerjim®
05-31-2004, 03:35 AM
think about this:

your crankcase makes pressure on its own. so,
your doing a 1/4 mile pull, shifting fast, gear after gear, for 13-14 seconds. that whole time the crankcase cannot releve pressure because the checkvale has it closed. = bad.

swartz
05-31-2004, 03:37 AM
ahh i didnt tthink about it being closed.... right now nothing is suckin on my valve cover lol.

what about that spring tube that goes from the manifold to the block?

bimmerjim®
05-31-2004, 04:45 AM
thats for oil return

diegom6
05-31-2004, 11:26 AM
ahh i didnt tthink about it being closed.... right now nothing is suckin on my valve cover lol.

what about that spring tube that goes from the manifold to the block?

I cutted the spring tube, made a "T" , locked the inside tube (the return of the oil to the block) with weld and the ran a tube from there (top part of that tube) at one device (OEM BMW) that separates the oil from vapors and the ran the rest of the hose to the air scuker elbow filter. The oil cointended in the device is returned by another hose to the oil pan (made a "Y" pipe on the oil return of the turbo).

The valve cover is now 100% sealed, no problems since....

swartz
05-31-2004, 12:18 PM
that sounds complicated

diegom6
05-31-2004, 12:45 PM
that sounds complicated

I make complicated sentences....lol

I explained to Dan Pindar....he did the same as me...let me find the creative draw that I made...lol

JasenWFO
05-31-2004, 02:50 PM
One of these

http://store.summitracing.com/partdetail.asp?part=MOR%2D97800

Mounted to one of these pointed downstream in your down pipe just after your O2:

http://store.summitracing.com/partdetail.asp?part=MOR%2D97810

Attach a simple heater hose between the valve and your crank case breather. The exhaust gas rushing past the end of the pipe will open the check valve drawing the crank case pressure down, much the same way if you pass air across a cylinder filled with a liquid will draw the liquid out of the cylinder. This has two effects: 1) lowers your crankcase pressure and 2) by lowering your crank case pressure you get better compression ring sealing (makes more power). Venting the crank case this way also eliminates a contaminated intake charge with oil vapor.
I have these on my car, I'll snap some pics and post them.

swartz
05-31-2004, 02:57 PM
how bad is it to just run a breather filter off the valve cover. ive seen it before on many dif cars?

JasenWFO
05-31-2004, 02:58 PM
This is installed on my engine, but you can get the same effect:

http://jasenwfo.0catch.com/images/Malibu/Breather.JPG

http://jasenwfo.0catch.com/images/Malibu/Valve.JPG

swartz
05-31-2004, 03:10 PM
what kinda car and engine is that?

JasenWFO
05-31-2004, 03:28 PM
One of my silly cars, it's a 439 Big Block Chevy. On paper it should make 770 FWHP, but it has some issues.
Here's a dyno run to 7900 RPM:

http://jasenwfo.0catch.com/images/Malibu/MOV07335.MPG

Dan Pinder
05-31-2004, 04:01 PM
Actually I am running a breather on my valve cover.

I had my cover welded over and made a hole for a v8 breather filter. I didn't realize that the spring tube doesn't even connect to the inside of the manifold.


If you do not seperate the valve cover vent from the manifold at boost, the crank case will pressurize and that pressure will be seen at the oil drain side of the turbo... a very bad thing.

:)

swartz
05-31-2004, 04:12 PM
the spring tube doesnt get pressurized from the intake manifold?

Giga Shadow
05-31-2004, 09:49 PM
http://jasenwfo.0catch.com/images/Malibu/Breather.JPG

http://jasenwfo.0catch.com/images/Malibu/Valve.JPG


Does that set up pull air out the same, or even FASTER then when hooked up to the intake?
Does exhaust ever go up the hose?

JasenWFO
05-31-2004, 10:47 PM
The exhaust is prevented from backing up the hose by the one way check valve at the end welded in the exhaust tube. The crank case gas is pulled at more of an optimal point with this setup rather than using an intake setup. When you are at wide open throttle, you are producing the most crank case pressure and have the least manifold vacuum to draw it out with a conventional intake PCV system. Wide open throttle with this setup will draw the crank case pressure out faster as your exhaust gas velocity is at its highest at wide open throttle. The exhaust gas velocity is what creates the negative pressure to open the one way check valve and draw the crank case gas through the tubes.
From a physics standpoint it works like the negative pressure created on the backside of an object moving through the air. What you are doing with the exhaust setup is using the exhaust gas molecules as the object moving in a particular direction creating the low pressure. The low pressure (vacuum if you wish) created by this flow will draw your crankcase down faster.
If any of you do decide to use this setup, make sure you install the bung and the check valve down stream of the O2 sensor. The oil vapor from the crank case gas will contaminate your O2 sensor if you install it before the O2 sensor.
This setup has been known to make 5-20 extra HP depending on how loose your compression rings are. The negative crank case pressure draws the compression rings tighter against the cylinder walls therefore creating less blowby and preserves the pressure in the combustion chamber to create power rather than blowing by in the crank case.

diegom6
06-01-2004, 12:50 AM
swartz, I hosted my draw, here you can from what I'm talking about, that is what I made except that I'm runing a oil/vapor separator device (OEM BMW) just from the modded spring tube....

The vaccum valve cover you will want to seal, you don't want oil sprayed in all your engine bay... :lol:

http://www.we-todd-did-racing.com/wetoddimage.wtdr/wNDE2MDgyNnM0MTNkZmQzMXk1NDE%3D.jpg


Hope Helps

let me know if you have some doubt

swartz
06-01-2004, 12:57 AM
thats a good idea. im afraid i might be pressurizing my engine.

swartz
06-01-2004, 12:57 AM
ur drawing explains it perfect. thank you for explaining

diegom6
06-01-2004, 01:00 AM
ur drawing explains it perfect. thank you for explaining

I knew it ...lol, my words trying to explain make it worst to understand than making the draw...lol

no problem wit the pressurizing, you will run absolutly well following this setup...trust me...