PCV Valve / Rocker Cover Breather

[Rory]

Well I'm just meaning is that bad the way the stock setup is or is it ok because the intercooler will trap any oil?

Also does more oil come out of one breather compared to the other due to the baffle plate in the rocker cover that weeJohn mentioned?

I'd think this would be the case as I only have a small rubber pipe on the middle breather at the moment and there is oil traces at the end of the pipe and previously when I had a filter there it was very oily. Whereas the pcv pipe seemed pretty clean when I had it off and the inlet manifold was spotless inside too.

@ Gee, I didn't get any feedback.

From what ive read, the only reason the breather is vented int the intake id for emmissions? Weather or not this is right, im unsure.

As for which one breathes heavier, im also unsure. Will have to check the colour of the hoses next time out in the garage (this would be my only indication)

 

[WallaceGlanza]

Lol cheers, I was only joking though I haven't really helped.

Rory what I was trying to get at was if its bad having the breather vented into the inlet after the intercooler as apposed to the stock setup of before? I'm guessing the intercooler would catch any oil/vapours that aren't caught in the catch can, this is obviously where your setup is better as its guaranteed that nothing will be getting back into the intake.

As Gee said earlier this seems such a simple thing yet there's so many different ways and opinions to do it!?

 

[Gee]

Hi Dan,

Thanks for taking the time to draw that diagram.

My filter intake is silicone hose, are you suggesting a plumb a line into that somehow?

RedHot,

Some feedback from other members as to why my setup could probably be wrong or cause issues:

The filtered catch can setup is perfectly ok for racing setup where just venting the blowby gasses is ok.
Race setups dont need to worry about oil contamination as its changed very regularly anyway (ie, every meet).
The problem is lots of people then see these "race" setups and think whats good for race is good for a street car.
Hence why there are sooo many catch cans around that are setup incorrectly.

Street cars oil need to last a lot longer though, and thats why the PCV system exists.
Its not just there for emissions, its there to lengthen the life of the oil and stop a few other effects that blowby gas can create (like corrosion due to condensation).
You can still have a catch can with a normal functioning PCV system... it just needs to be setup properly

PCV is a Positive Crankcase Ventilation system.... therefore it is there to relieve the pressure caused by the small amount of blow by all cars create....

This is THE common misconception!
Read those pages i linked to... its not just about "relieving the pressure caused", its also to put fresh air into the crankcase.

The links:

http://rdx.acurazine.com/forums/showthread.php?t=682236
http://www.machinerylubrication.com/articl...p?articleid=234

And a Toyota mechanic guide:

http://www.autoshop101.com/forms/h63.pdf

Steps to correct setup from another member:

The vent that goes from between 1&2 spark plugs to the plastic inlet tubing (or factory BOV) leave as is.... it doesnt need to be changed at all.

Remove the pipe that goes from the PCV valve to the intake manifold.
Plumb a pipe from the PCV valve to the inlet of the catch-can.
Plumb a pipe from the outlet of the catch-can back to the inlet manifold.

The catch-can should be sealed (no air-filter) and have internal baffles of some type (a maze, steel wool, etc).

I am not posting this stuff to agree or disagree with anyone's comments, advice or suggestions. I am simpy making all of this information available to everyone for educational purposes. I have not read the links myself yet, but I will be.

What turned out to what is supposed to be a simple setup turned out to be educational or this forum and on Aus Starlet Club.

For more also see here:

http://www.austarletclub.com/forums/index.php?showtopic=11785

 

[dan_ep82]

yep gee just get a silicone t piece off ebay

 

[Gee]

yep gee just get a silicone t piece off ebay

According to those links, is the PCV valve not there to also let clean air back in? So should not be removed completely?

 

[dan_ep82]

personally i would't worry, the way i have drawn will do exactly the same as stock look on any of the big power supras etc they have them plumbed in the same way as i have drawn.

clean air will never enter via pcv valve as it flows outwards only and the breather goes into the efi pipe in stock form the same as the way i have draw

 

[Rory]

Lol cheers, I was only joking though I haven't really helped.

Rory what I was trying to get at was if its bad having the breather vented into the inlet after the intercooler as apposed to the stock setup of before? I'm guessing the intercooler would catch any oil/vapours that aren't caught in the catch can, this is obviously where your setup is better as its guaranteed that nothing will be getting back into the intake.

As Gee said earlier this seems such a simple thing yet there's so many different ways and opinions to do it!?

Exactumundo

So many diffirent ways, its down to personal choice really.

 

[Gee]

Yeah it is personal choice.

But I'd rather have the safer setup that is working properly and not contaminating my oil etc etc.

Going to get another rocker and maybe change the setup.

 

[dan_ep82]

why? if you done it the way i draw it will work better than using a pcv valve

 

[Gee]

What part of the setup you have drawn puts fresh air back into the engine Dan?

 

[dan_ep82]

on the stock setup what lets fresh air back into the engine?

 

[davehart]

The way Dan has drawn it is exaclty the same as the stock setup if you were to leave the pcv valve as it is.

It just puts the can in the place of the re-circulating bov to catch the oil from the rocker outlet.

 

[dan_ep82]

The way Dan has drawn it is exaclty the same as the stock setup if you were to leave the pcv valve as it is.

It just puts the can in the place of the re-circulating bov to catch the oil from the rocker outlet.

the way i have drawn gets rid of the pcv valve too, as it would't be needed.

 

[dan_ep82]

paul whifins supra runs exactly the same setup i just drew, im sure a starlet will be fine

 

[davehart]

Thats the setup I'll be installing but as I've still got a top mount it will just be a closed system that runs it back into the intake where the stock re-circ bov is.

Leaving the pcv system as it is as my can has two inlets.

 

[Rory]

paul whifins supra runs exactly the same setup i just drew, im sure a starlet will be fine

Still cant think, why would you want to have the risk of contaminating the inlet charge?

BUT as stated above, do as you see fit.

 

[dan_ep82]

the catch can catches the contamination tho

 

[Gee]

Yeah thats right.

From the pressure drop of the fumes going into the catch can, the fumes drop to the bottom of the can or turn into droplets. Thats what all the shit is that gets emptied out of the can.

Also helps if the can has some baffle inside, like metal wire. I will be doing this.

 

[munday]

Will the can really catch 100% of it though? I highly doubt it, which is why i personally would vent it to atmosphere. I'm with Rory (well not WITH him) :kiss: :slap:

 

[Gee]

No it won't, but I doubt any setup will without some sort of vacumm like an electronic pump or exhaust valve?

But it will help...