mastamind

Give me some more pros and cons on this. From research I read that the PCV valve closes under boost, which is not good for ring lands to my understanding. So does a hollowed out PCV valve leave the motor vulnerable to misfires? How about if you hollowed out the PCV valve and ran it to a catch can? Would the can quickly fill with oil if hooked up to the intake manifold vacuum source?

I know why people mod the PCV valve, I'm looking for the downfalls of it. I'll be boosting next year and want to make sure I get this covered. I already read a couple of great threads here on crankcase ventilation.

igo4bmx

if you hollowed out the pcv and left it in stock configuration you will pressurize the crankcase.

1158

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by igo4bmx &raquo;</TD></TR><TR><TD CLASS="quote">if you hollowed out the pcv and left it in stock configuration you will pressurize the crankcase.</TD></TR></TABLE>

As you implied, only if you run the line to the intake.

I hollowed out mine and am running it to a cath can. The can should not fill with oil because the baffle(black box on the block) will prevent oil from traveling up the line.

SovXietday

There's a little "black box" that acts as an OEM catchcan, vent that to atmosphere, hollow out your PCV, and vent your valve cover to atmosphere as well.

mastamind

There isn't a black breather box on my block and I installed a Moroso (closed not open breather) catch can between the PCV valve and intake manifold. When the time comes I will just ventilate the crank case from the back of the block and run it to a open breather catch can, hopefully all goes well.

Thanks for the replies fellas, I usually don't get any.





Modified by mastamind at 12:18 PM 10/4/2006

1158

My catch can has 2 fittings on it. I'm running the PCV valve to one and the valve cover nipple to the other. I think it will work, but I can't say for sure yet. I have not started up the car or gotten it tuned.

mastamind

Why don't you run a breather filter off the valve cover nipple, and then ventilate the crank case through the extra port on the catch can.

Just curious!

boostincoupe

I run the OEM black box, both ports vented to the atmosphere and the block port plugged (stock GSR IM has a nipple on the IM, I'm running an Edelbrock manifold which doesn't have one). Threw the PCV valve in the trash, and run a breather filter on the valve cover.

Doesn't get much more vented than that, and it's basically free (unless you run valve cover vents, b@ller style).

1158

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mastamind &raquo;</TD></TR><TR><TD CLASS="quote">Why don't you run a breather filter off the valve cover nipple, and then ventilate the crank case through the extra port on the catch can.

Just curious!</TD></TR></TABLE>

Because I have the second port on the catch can and because I know for our state inspection (NC) they give a quick look at the pcv setup. The hose looks like it goes the the intake pipe, but doesn't.

adseguy

I'm running it just like boostincoupe, but I left the ports on the OEM blackbox open. At high boost enough oil squirts out where it will hit the IM and burn off as oil vapor. I will be running lines to the bottomof the car so oil can vent there. I just hope it's not a lot of oil in the end .

For high HP cars, I suggest NOT routing any of the oil back to any intake source as this will reduce octane levels.

teg racer 877

the best way is to take the freeze plugs off the back of the block and run fittings with hoses to a catch can, that way the blowby can come out directly fron the block and not have to travel up the passages to get out of the vc.

but if u dont want to do that, the next best would be to keep the pcv valve in tact and connected like it was NA, that way under vac. it will still suck the unburnt fumes out into the mani., and under boost it will close, and then run ur other line on the vc to an open breather or catch can