PCV System

[1ViciousGSX]

Originally Posted by Andrew7dg

Not picking on you but the vent on the side sees lots of vacuum when the turbo is spooling. Thats when the engine needs vacuum under boost. When it is at idle (off boost) for example, is when it doesn't see much vacuum however that when the PVC valve works and is sucking air out.

The other reason that it is routed into the intake line is because it needs metered air.

So the people that have vents on the side of their valve cover are also pulling in unmetered air through the PVC system. Kind of like what I am dealing with using a GM MAFT

Not picking on you either, but the last thing I want on on my turbo inlet is vacuum. It doesn't really matter because once you go WOT there is no vacuum at the PCV.

[Kracka]

Best solution yet:

Use Krank Vents and have them open to the atmospehere (both the crankcase breather and PCV ports on the valve cover). You can either retain the stock PCV valve and hook up the KV to that, gut the stock PCV valve which is a better decision, or even better yet use the nipple from a stock 1G intake manifold where the PCV gets routed back in and screw that into the PCV port in the valve cover. The whole purpose of this is to let air out, but none in. The crankcase vacuum should help the pistons rings seal better thereby reducing or eliminating blow-by which is partly what causes crankcase pressurization and oil consumption.

[Andrew7dg]

Originally Posted by 1ViciousGSX

Not picking on you either, but the last thing I want on on my turbo inlet is vacuum. It doesn't really matter because once you go WOT there is not vacuum at the PCV.

so, if you don't mind me asking, what do you have on the side of the valve cover. is that were you have your catch can? is it venting off to the atmosphere or is it sealed?

[1ViciousGSX]

Originally Posted by Andrew7dg

so, if you don't mind me asking, what do you have on the side of the valve cover. is that were you have your catch can? is it venting off to the atmosphere or is it sealed?

Catch can breather venting to the atmosphere.

[Andrew7dg]

Originally Posted by 1ViciousGSX

Catch can breather venting to the atmosphere.

A setup like your only take care of half of "crankcase ventilation", it will be enough to relief pressure in most cases but it will do nothing to ventilate crankcase due to lack of vacuum in the system, ventilation as in removing blow by and contaminates which will settle into your oil if not pulled out.

[1ViciousGSX]

Originally Posted by Andrew7dg

A setup like your only take care of half of "crankcase ventilation", it will be enough to relief pressure in most cases but it will do nothing to ventilate crankcase due to lack of vacuum in the system, ventilation as in removing blow by and contaminates which will settle into your oil if not pulled out.

What do you think the PCV is for???

Here is how it works, at idle and cruise intake vacuum from the intake manifold is transfered thru the PCV hose, throught the PCV valve, thru the engine and on to the breather. All the breather does is supply incoming air to counter act the vacuum inside the engine which removes fumes and contaminants by sucking them into the intake to burn in the engine. So whether you get the fresh air from the intake pipe after the air filter, but before the turbo or from an external breather, it doesn't matter to the PCV system. At WOT there is no vacuum, so the PCV shuts closed and is not used.

So would you rather have the fumes and contaminants go out thru an external breather/catch can or feed it into your turbo at WOT?

[Andrew7dg]

It flows both ways. Under boost, the PCV closes, and blowby and other CC leaks need a way out - through the VC breather. It helps to have vacuum to pull gasses out or they stay in the oil.

If you look at my arrangement I do have a catch can but it is sealed and hooked up back to the intake tube. So get the best of both, vacuum and something to filter out the crud that comes out the VC breather so it doesn't go into the turbo.

[1ViciousGSX]

Originally Posted by Andrew7dg

It flows both ways. Under boost, the PCV closes, and blowby and other CC leaks need a way out - through the VC breather. It helps to have vacuum to pull gasses out or they stay in the oil.

Yeah, I think I covered that already. The stock PCV system do not create a vacuum in the crankcase either, it only moves air thru the crankcase. You want a vacuum on the crankcase, block off the breather port. And then watch oil shoot out of every possible area under boost.

With the amount of blowby coming out of our engines under high boost, you'll never have a vacuum inside the crankcase. Even if you could put together a system to create a vacuum in the crankcase under full boost. the gains would not offset the effort.

Possitive Crankcase Ventilation. Not Positive Crankcase Vacuum, get it?

[1ViciousGSX]

Originally Posted by Andrew7dg

If you look at my arrangement I do have a catch can but it is sealed and hooked up back to the intake tube. So get the best of both, vacuum and something to filter out the crud that comes out the VC breather so it doesn't go into the turbo.

When was the last time you looked at your compressor wheel to see if it's crud free?

[blageo23]

Originally Posted by 1ViciousGSX

Not picking on you either, but the last thing I want on on my turbo inlet is vacuum. It doesn't really matter because once you go WOT there is no vacuum at the PCV.

When at WOT the PCV system goes in reverse because of the boost. Thats why you get oil in the intake because the blowby goes through the breather side and into the intake.

[1ViciousGSX]

Originally Posted by blageo23

When at WOT the PCV system goes in reverse because of the boost. Thats why you get oil in the intake because the blowby goes through the breather side and into the intake.

That's why I have a catchcan/breather, so that doesn't happen.

The system doesn't go in reverse, the PCV valve closes off the flow under boost, what comes out of the breather is blowby.

[blageo23]

Thats what i ment by reverse. Just in the intake hose it goes back into the intake.

[Kracka]

If the pressure inside the crankcase is greater than the boost level then the PCV valve will open, even while WOT under boost.

Seriously, I think Krank Vents would solve everyone's problem. No more blow-by (or at least seriously less), all the gasses and crap can flow out, and no crap being thrown into the intake track. No more dipstick popping out, better engine efficiency, and less resistance on the engine internals.

[1ViciousGSX]

Originally Posted by S2kracka

If the pressure inside the crankcase is greater than the boost level then the PCV valve will open, even while WOT under boost.

Seriously, I think Krank Vents would solve everyone's problem. No more blow-by (or at least seriously less), all the gasses and crap can flow out, and no crap being thrown into the intake track. No more dipstick popping out, better engine efficiency, and less resistance on the engine internals.

DUDE, if you ever see 30 psi in the crankcase with a vented system, let me know how long it took to blow all of the seals out or lift the valve cover!

You can't say there is no more blowby, it's always there. It's just how you get rid of it that counts.

[Kracka]

Originally Posted by 1ViciousGSX

DUDE, if you ever see 30 psi in the crankcase with a vented system, let me know how long it took to blow all of the seals out or lift the valve cover!

You can't say there is no more blowby, it's always there. It's just how you get rid of it that counts.

I said IF, not ALWAYS. Not to mention, most factory PCV valves, especially the plastic ones, leak boost into the crankcase. I can say there is no or less blowby since a vacuum in the crankcase helps the piston rings seal better. You can scream all you want about how its impossible and that the crankcase is always going to see preasure blah blah blah blah but Krank Vents and other similar projects have been tested on numerous applications and are always found to be beneficial. One easy to understand real world example is the fact that the dipstick won't pop out anymore. The dipstick will only pop out when the crankcase is seeing preasure, which these Krank Vents eliminate and all of a sudden rather than the dipstick being popped out its being sucked in.

[1ViciousGSX]

I would be highly surprised if the Kranks vents do anything else more than seal off the boost from the intake manifold. Our cars have metal PCV valves, at least my 2g does. No Krank valve on my car, the system works as it's supposed to, and I've never had a dipstick pop out. So maybe I'm just not seeing the miracle cure you guys are seeing. As long as you can relieve the crankcase pressure under WOT boost conditions, the stock PCV will work fine under normal driving condiions. That's all I'm saying.

[Kracka]

I think we are going in circles here and we're both right, but still not agreeing

A stock PCV system will work fine under normal driving conditions, but what I'm trying to get at is these KV's will help create a crankcase vacuum which has many benefits. They aren't exactly cheap, but they work as claimed.

Now lets hug!

[Andrew7dg]

wow leave for lunch and a bunch of stuff is said....

ok...

I would like to state I don't have any crap in my compressor wheel or intake tube because of my setup. It is pretty much the origional setup but with filters and a heavy duty check valve.

Look at my set up for just a second...

Breather side : VC -> catch can (sealed) -> intake pipe.

intake goes before the turbo just to clarify so it never sees boost

Catch can catches everything that the VC spits out which is kind of a lot of crud. After it is filtered it goes into the turbo. No crap.

Now why don't I just vent to the atmosphere like everyone else...

Because I believe that under high boost/ WOT when the PVC valve is closed there is a lot of blow by. This Breather side takes pressure out because the turbo take in so much air that it creates a vacuum (again before turbo) By having some sort of vacuum on it will take away pressure PLUS suck out unwanted gas. If you have it vented to the atmosphere there is a weird gas smell which I don't like. If this is hooked up to the turbo inlet tube. It does reburn it but it doesn't have the oil to go with it because the catch can caught it.

Make it short

No boost---> air going into valve cover side
Boost ---> air going out of valve cover side

If you have it vented to the atmosphere air goes in (no boost). However when you are running boost, there is pressure in the crank case and it need to go somewhere and by pressure it forces itself out of the breather side and you get weird smelling fumes

The other side

PCV side : VC -> PCV -> optional 2nd catch can (sealed) -> heavy duty check valve -> intake manifold.


I don't get that much crap in this filter but it still works.

I have a heavy duty check valve (good up to 125psi) that helps the pvc valve out. What people are experincing with just using the PVC valve is that the PVC valve won't hold high pressure boost and get pressure going the wrong direction.
Some people have installed the check valve without the catch can and still get good results. Since mine is a street driver I want to be safe and install another filtration system so my intake manifold and heavy duty check valve doesn't plug

Air only goes one way out of this system and that is into the intake manifold.

I have 3 more check valve selling for $2.00. easy for high boost applications.

Now why don't I just remove the PVC valve then? The PVC valve is calibrated for flow ratings. Thats why there is a spring and cost about $110 instead of my easy $2.00 part


This is how I have my system set up. It works for me just fine. I don't get any gas smells plus my turbo, intake, and intercooler is clean. I can also run high boost on my PVC valve with out it failing on me.


Now going onto this expensive $110 kit. I think it is shiny, crome and does everything that the $2.00 part does on the PVC side. However it also puts a check valve on the Breather side. What would this do though... When there is positive crank case (boost) it would let gasses leave, (off boost PVC valve open) it would block air going into the engine. There would be a vacuum at the pvc valve and no air going into the breathing side so what happens, the system has high vacuum and thats why you get the air wooshing in when you pull the dip stick.

http://dsm.dejonpowerhouse.com/
Has the product and look how it is set up.

[1ViciousGSX]

Originally Posted by S2kracka

I think we are going in circles here and we're both right, but still not agreeing

A stock PCV system will work fine under normal driving conditions, but what I'm trying to get at is these KV's will help create a crankcase vacuum which has many benefits. They aren't exactly cheap, but they work as claimed.

Now lets hug!