Crankcase Ventilation - Supercharged Application

[dzolalaw]

Hello guys:

I am looking for some ideas for crankcase vent setups on supercharged 5.0's. I'm running 5lbs of boost off my intercooled procharger. I am experiencing the obvious sign of crankcase pressurization with oil leakage from gasket areas. All gaskets are brand new with less than 250 miles on them.

I am currently running the pcv system with no valve cover breathers. The pcv is stock, but brand new.

I am looking for any photos or diagrams of ventilation set ups using the pcv system that have worked for you in either eliminating or minimizing oil seepage.

Any and all help would be greatly appreciated.

 

[a91what]

Do you still have the tube from the valve cover to throttle body installed? If you do take it off. Plug the TB tube and place a breather on the valve cover port. For the pcv place a filter directly on the pcv valve. This is a temp fix but works.

A vented catch can with 3/8 ports, take the Valbe cover and pcv valve to the can. Plug the manifold lines

 

[dzolalaw]

Here is my set up. I have alcohol injection ported into what was the nipple for the stock crankcase vent set up. Following prochargers instructions, I ran 3/8" hose from the nipple on the oil fill neck to a Brass T fitting above the pcv valve. The bottom of the T is connected to the pcv valve (on stock pcv there are two ports, I capped one). The exit side of the Brass T is fitted with more 3/8" hose which runs all the way to 1" of the air filter. Now, because I was still seeing seepage, I recently spliced in an RJC aftermarket pcv valve just after the exit end of the brass T. I did this because I have heard that the stock pcv's simply don't work under boosted conditions.

I attached a photo to illustrate.

Any help or comments from those with experience with venting supercharged motors is greatly appreciated.

Thanks,
Daniel

 

[mikestang63]

Odd that you are experiencing such issues at only 5# of boost. Here is a simple setup that works

1. Remove the vent tube from the passenger valve cover to the throttle body
2. cap off the nipples on the valve cover and throttle body
3. replace the stock closed oil fill cap with a breather element cap
4. replace the stock PCV valve with a one way PCV check valve from a turbo coupe

Easy peasy

IF you still encounter excessive pressure, then remove the PCV valve and lines altogther, plug off the PCV ooening and run a hose from the valve covers to a catch can with open element breathers. I can't see why you would need that with only 5# though. I'm running 10# at max boost and run the system outlined above with no issues.

 

[nickster1]

Bringing this one back from the dead. I'm figuring out this "new" car (new to me) and supercharger (new to me as well - first one I'v had).

The current setup is seeing tons of oil in the intake tract as well as popping the dipstick - so obviously seeing lots of crankcase pressure. The car came with the PCV in place (actually hanging off and not connected) at back of manifold (Holley Systemax) connected to a Steeda oil separator and then Tee'd back into the "Source" line coming from the firewall mounted vacuum tree. I also have a breather cap on my valve cover and the line from the oil filler tube and throttle body are capped off.

First diagram is what is currently on the car - besides the obvious oil contamination, I don't like the PCV Tee'd into the "S" source vacuum especially if it's sucking oil. I would rather have straight runs for anything that needs vacuum. So, on the Holley - I have one of these metal vacuum trees with enough ports on it to accomplish everything I need (2nd pic). The only issue is that the Source vacuum and the PCV vacuum is sized at 3/8 hose and there is only one 3/8 port on the metal tree in the center - the other ports are sized smaller and of differing sizes.

Can I run the PCV into the 3/8 port and just use a reducer to run the 3/8 "S" source vacuum line (orange line - 3rd pic) into the 5/16 hose and into the appropriate port on the metal vacuum tree? Will that have any adverse effects on the other accessories running off the tree (AC, cruise and brake booster) if I run to a slightly smaller hose/port?

The other question I have is I want to replace the breather with a CFM check-valve breather to vent the crankcase as needed and remove the oil-soaked regular breather and also insert a metal check valve after the oil separator in the PCV line. Anyone see any issues with this? And do I have the flow of the check valve and oil separator correct (as shown by the arrows)? As this is a street-driven car - i'd like to keep the PCV functioning. And I've read so many different opinions on this that it's gotten pretty confusing. I'm thinking that PCV should either be run closed and without regular breather (remember I'll be running a check-valve breather keeping the system closed) or open with PCV removed and catch can vented valve covers.

Does that sound about right?

I have this post up on the corral as well and one member commented that I need a source of fresh air for the PCV? My response was that for the fresh air - I thought that wasn't needed since this is a closed system but I guess that's not accurate? Since this is a blow-thru setup - would it make more sense to put back the tube between the TB and VC? That way it's metered air after the MAF and any bi-directional crankcase venting would be handled by the CFM check-valve breather element since it would be the path of least resistance (rather than the small TB/VC cross-over hose)?

 

[nickster1]

TTT - looking for any responses please

 

[General karthief]

Read through this thread, it may answer your question:
http://forums.stangnet.com/showthread.php?t=642930&highlight=pcv

 

[nickster1]

Thanks General, the only issue with that is that it's using un-metered air to feed into VC. I'm trying to keep the air metered which would mean i would have to grab it after maf and before TB. Trying to see if anyone has been able to work up a solution that might work - maybe with an inline reducing valve or similar.