91zxtt

So, what were saying is that by blocking off your PCV, you will not solve your problem, but you will probably create others. The PCV's are there for a reason....leave them there. If they don't work, then replace them.

ZLover4Life

Well, some people put breather filters on instead, because it isn't necessary to vent into the plenum, but it is absolutely important to vent the crankcase in some way... so yes, blocking the ventilation is a horrible idea.

snwbrderphat540

filters arent an effective form of suction thats why they made the PCV valve for the vacumme. they all used to just be a filtered hole but the lowerpressure air created when moving only does so much. but either way you need some way for the crank case to breath

ZLover4Life

They purge into the intake more for emissions reasons. The vacuum from the manifold keeps the valve closed, it doesn't open it... therefore, installing a filter instead of venting into the plenum will have the result of venting more... interpret that as good or bad as you will. But it's called *positive* crankcase ventilation for a reason - it's venting positive pressures (it doesn't get drawn out by vacuum).

sebas450

my turbo is new and my ring is new he smoke when i deccelerating and when i shift why he smoke blue if its not the pcv its what

ZLover4Life

... did you read this thread at all??

There's your answer.

Comorat2x2

You hurt my head....

snwbrderphat540

you sure aboot that. valves work one way, so if works when there is pressure inside the crank case it should work if there is a vacume on the other side of it. at least thats how the last PCV valve worked when i played around with it. then again it was from 75. also i believe i read a nice article on that once how the manifold mounted PCV was more effective than the previous style open block filter method

ZLover4Life

Here's the best explanation I could find...

You're thinking of it too simplistically. Think of it somewhat like a traditional recirculation valve on a turbocharged car. With your reasoning, boost would open a recirculation valve on its own, when in reality, due to the design of the piston and spring inside the blow off valve, it's the relatively minuscule amount of vacuum that opens it. (That might be a bad example, but I'll stick with it.)

With how the PCV valve is designed, the vacuum from the manifold keeps the valve closed. A loss in vacuum allows the spring to open the valve more, thus allowing more ventilation. With no vacuum at all (PCV's venting into the atmosphere), the valves are open all the way because there is no resistance to the spring.

So your logic follows in simplistic form (if vacuum closed it on one end, positive pressure on the other end would surely also close it), but it ignores the spring that is actually opening it and the fact that vacuum keeps it closed. Pressure in itself does not open the valve (the spring must be stronger than the pressure it is meant to purge) - it is open by virtue of its design... vacuum simply closes it.

snwbrderphat540

ahhh.... ball. check valve. i gets it. i thought it was a simple valve not a check valve. also, blow by is funny. lol. i remember my buddie had to tie down his dipstick other wise it shot out into his hood. lol.

ZLover4Life

... I've done that... plastic bag over the dipstick and tube with a rubber band to hold it down. (PCV valves were fine, I could never figure out why it'd do it above 14psi.)

And for the record, I'm not supporting breather filters over the stock arrangement... I willingly admit that I have no knowledge of the benefits of each arrangement. I only know that a lot of people who heavily track their Z's will relocate the PCV's to higher up on the valve covers to prevent oil burning on hard cornering (which the Z32 is known for).