PCV valve and vacuum hose placement

[paluka21]

Here is my findings after asking the techs at ATI about a possible blow by issue with white smoke coming from the breather on the valve cover.
I explained to them that in the directions for the 94-95 cars, you are to run a vacuum line from the nipple on the valve cover, to a T fitting above the pvc valve. Then the other side of the pvc valve which used to get run back into the upper intake manifold, now gets vented to atmosphere, and the vacuum port on the upper intake is plugged off.
I asked them about positive crank case vacuum, and possibly the blow by is caused by not enough of this, and if running the other side of the pvc valve that is to vented atmosphere, back into the upper intake manifold, only with a one way check valve before the manifold would cure this issue. Here is their response via email: (note: they responded within 20 mins of my email :) )

Dear Dan,

Installing a one way check valve would not work, since the when it would
be going into boost it would close. Thus in turn would be bad since you
would now have no place for the venting gas to go. So I urge you NOT to do
that. The tube will then need to be run into the INTAKE side of the blower,
as in the filter or neck going into the impeller. The excessive amount of
smoking, might indicate you to do a leak down test, and a compression test.
If the blow by, is a lot you will not want to plumb it back into the intake
track since then it will cause oil detonation. You would then have to buy a
vacuum pump and pull the press from the crank case, and plumb it into the
x-pipe or h-pipe. There is a lot of ways about going about this issue. The
costly one of the bunch is a motor rebuild.

Regards,
ATI

Thoughts?
Dan

[WA2FAST]

I know I have asked you this before... how is yours setup again? If I remember correctly, it is just like ATI says, only with a breather on the valve cover... right?

I would still like to know the real story behind having vacuum evacuate the crank case anyway because I have heard that you do need vacuum to keep the rings sealing correctly (or something allong those lines) and I have heard that you don't need vacuum at all and it is only there to evacuate the crank case. I don't know... but if that is the case, why can't you just vent the PCV to a catch can or atmosphere, slap a breather on, cap all vacuum lines and call it a day?

[SnakeIs]

I believe strongly that the motor must have vacumn present in the crank case. This is needed to keep the seals from leaking and the rings to seat better. I think the idea of the forced induction PCV valve and the check valve inline is suitable as long as your running a breather on the valve cover. The breather will let any pressure escape when the pcv valve is shut. I have ran mine like this for ages now and no problems at all. The dipstick even stays in now under hard boost and no oil leaks at all from the front seal (which it did when I had the pcv just vented as per ATI's instructions) If you think about it, all vehicles from the factory have a PCV system with vecumn present in the crank case...

[WA2FAST]

Okay... so how do you have yours setup then Snake? It sounds like you have it set up the way that I was thinking, but I'm not sure... how did you do yours?

[SnakeIs]

I have the valve cover nipple covered with a vacumn cap and a nice shielded K&N in place of the oil cap. I have the PCV valve off of a 85-86 turbo Buick and its running via 3/8 hose right into the upper intake. No more blown dipstick and no more oil leaking out of my front seal... I have yet to find a one way check valve to put in line with the PCV but I haven't had any problems as of yet.

[WA2FAST]

How much boost are you running? Do you have a part number for that PCV by chance? What brand is it? Are you using the factory form fitted PCV hose, or are you using a different hose? If so, which one?

Sorry for all of the questions, but that is EXACTLY what I want to do with mine and have bassicaly decided on. I want to also get a Check valve in there as well, but again don't know what will fit or work. I just want to hit up the auto parts store one more time to get everything at once... I have made a million and a half trips there since the begining and it's getting old now, so I want to at least try to get everything in one fell swoop if possible.

[paluka21]

I have mine setup the way ATI says, a 3/8" hose from the nipple on the valve cover to a T above the pcv valve, then other side vented to atmosphere. The fitting on the upper intake is capped and I have a breather on the valve cover.
I do have white smoke from the valve cover, and coming from the pvc hose that is vented to air. I also have oil pushing its way through the front seal at the crank, and oil coming from the valve cover through the filter, even though I have the stock baffle in the valve cover.
I have yet to blow the dipstick out or the pvc, however I would like to know how much of a difference it makes installing what Donnie (snakeis) has in place of his pvc valve, an SVO boost sensitive valve.
I have a one way check valve 'somewhere' in the garage I ordered a while ago but never used, however I am kind of reluctant to change the way the car is setup right now in fear of causing more, or additional harm.
donnie, I will give you a ring on your cellphone here soon, I just have to wait to make sure the funds are ok before I go sending the heads into a machine shop. I also need to buy head studs, new roller rocker bolts, new dowls for the block-head, and I'd like to get the lower ported to a 1250.
don,
if you do this setup, keep me posted on IM or just on here, I don't know if I will be doing it anytime soon, however it would be interesting to see if the white smoke would cease?

Dan

[WA2FAST]

I definitely will... I am probibly going to go out and get the parts as soon as I have my 8-rib blower belt cross refrenced with a goodyear gatorback and have it ordered. I still would like to find out the other questions I asked though so that I make sure I get the right stuff.