S&H Performance turbo build,

[BruceH]

It can work, the problem is under boost it only leaves that one little passenger side breather to vent the crankcase pressue. The higher boost from the manifold prevents the pcv valve from allowing the crankcase pressure out, effectively keeping it closed under boost. When you let off it will open back up and vent. By removing the boost from the top of the valve it allows the crankcase pressure to vent on that side as well as the p-side when under boost. On a turbo setup you want to vent the crankcase as much as you can sicne it generate full boost down lower in the rpm range. I would reccomend a oil fill neck breather as well. The passenger side being designed to or drawing in air to the crankcase is a myth.

I've seen a better description but this is all I can find at the moment. It's from the s197 workshop manual. Fresh air in one side and crankcase gasses out the other to be burned.

http://iihs.net/fsm/?dir=7&viewfile=Positive Crankcase Ventilation (PCV) System.pdf

 

[JoshK]

Oh look what I started now.

Just for sayings sake, I run breathers on both valve covers and will be installing the oil neck breather soon as well.

I believe the same size tap that you use on the oil pan works in the hole on the intake manifold to install a plug there. That is what I did on my intake manifold(actually used that for a source for my boost/vac gauge for awhile).

 

[jodadejss06gt]

I run open on the drivers side and the passenger side is open into a catch can.

 

[JeremyH]

I've seen a better description but this is all I can find at the moment. It's from the s197 workshop manual. Fresh air in one side and crankcase gasses out the other to be burned.

http://iihs.net/fsm/?dir=7&viewfile=Positive Crankcase Ventilation (PCV) System.pdf

Sorry for not clarifying, sure on a na setup Bruce where blowby pressure is minimal, during and after wot, when the pcv valve releases pressure a small amount is drawn in from the other side. I'm talking about boosted setups when there is a breather there. Pressure is much higher and that side only vents. Thats why leaving the other side closed routed to the manifold prevents the pcv from working correctly with boost. Its a myth that air is drawn in through that breather like some like to think.

 

[BruceH]

Oh look what I started now.

It's all good. This is just a friendly discussion. By no means do I claim to be an expert but I have fairly good recall of material I've read. I'm just relating my personal experiences. Now if it was about oil there would probably be some name calling, lol.

Sorry for not clarifying, sure on a na setup Bruce where blowby pressure is minimal, during and after wot, when the pcv valve releases pressure a small amount is drawn in from the other side. I'm talking about boosted setups when there is a breather there. Pressure is much higher and that side only vents. Thats why leaving the other side closed routed to the manifold prevents the pcv from working correctly with boost. Its a myth that air is drawn in through that breather like some like to think.

FWIW the only time I had oil residue on the passenger breather was with a breather on the other side. As long as the drivers side was hooked up no residue or blowby came out of the passenger side. It was only run like that after going to a blow though maf. The whole system was closed when it was suck through. I ran a closed system with my Whipple at up to 17psi too.

I know my crankcase couldn't overcome the pressure of full boost with the Paxton but it didn't hit max boost until higher rpms so I kept the semi closed setup. Max boost was only 10psi.

The Whipple was run as a closed set up at 17psi. No issues.

 

[JeremyH]

Makes perfect sense for those setups you had. Kinda funny but it seems to be progressive and go like this based on the way the different power adders operate:
PD/twin screw- closed works fine. (then again this is why you usualy see alot of oil in the blower intake when guys remove it later so a seperator wouldnt hurt)
Centri- half open half closed, can still to vent to atm under boost with the one breather since not always in high boost and the rest can be managed by the pcv coming off throttle.
Turbo- fully open and then some, the one breather doesnt cut it and alot of turbo guys will actualy end up making the valve cover openings larger to vent properly or adding the oil fill neck breather filter etc. Otherwise you back up the turbo oil drain affecting the turbo seals. Also fully open avoids getting any oil back through the turbo into the coldside and onto the the blow-thru maf etc.

 

[W3bb3r04]

What is the best way to do the breather set up? And what all is involved? Do they make them that replace the factory Pcv?

 

[mikeyfitz]

I just put this piece of ship rubber cap over the part on the intake and worm geared it on. Think that could cause a vacuum leak lol?

I'm runnin breathers

 

[JeremyH]

I just put this piece of ship rubber cap over the part on the intake and worm geared it on. Think that could cause a vacuum leak lol?

I'm runnin breathers

Been doing that as well since day one. lol

 

[mikeyfitz]

Hahaha good shit. I didn't think that would be why I'm at 12hg idle. But I have an idea as to why I was

 

[retfr8flyr]

I apologize for the hijack but since the thread got into PCV setups I thought I would explain what I am doing.

I currently run breathers on mine and I am tired of the oil smell that I get. I am redoing my setup and I'll see how it does. I have had #10 bungs welded into the covers and will run lines from them to a pair of open breather catch cans. On the drivers side I am installing a KrankVent PCV type valve in the breather line to prevent the air from back flowing into the cover and run a JPC catch can from the stock opening to the intake with another KrankVent in that line to prevent flow, I don't trust the stock PCV valve, from the intake to the cover under boost.

This setup should give me vacuum draw, for normal non boosted driving and take care of the oil fumes I normally get from the breathers. I will still have plenty of breather capacity, for the blow-by under boost, from the open breathers.


Earl

 

[908ssp]

Don't run breathers on your crankcase. You want vacuum and if you're worried about oil get catch cans.

http://www.enginebasics.com/Engine%20Basics%20Root%20Folder/Crankcase%20Ventilation.html

 

[retfr8flyr]

Don't run breathers on your crankcase. You want vacuum and if you're worried about oil get catch cans.

http://www.enginebasics.com/Engine Basics Root Folder/Crankcase Ventilation.html

All those descriptions would work fine on a N/A engine. When you start talking about blow through turbo setups, it's a different world.


Earl

 

[JeremyH]

All those descriptions would work fine on a N/A engine. When you start talking about blow through turbo setups, it's a different world.


Earl

+1.

 

[W3bb3r04]

What kind/brand of breathers should I buy? Links would be great!

 

[JoshK]

K&N part #s

62-1320

62-1340

KNfilters.com

 

[mikeyfitz]

I think the culprit to my vacuum leak is the waste gate down there. Think it's not as tight as it can be. It was a bitch to attach

 

[JoshK]

I thought I told you about hooking the line to the wg off the compressor housing Mikey? If you did that, then that can't be a vacuum leak.

 

[W3bb3r04]

The link didn't work for me Fuel

 

[mikeyfitz]

I thought I told you about hooking the line to the wg off the compressor housing Mikey? If you did that, then that can't be a vacuum leak.

I did, I mean the WG itself. The 2 pipes that hold it together.