Slow Z06

HEY.......Get off my Madd CraZzyyy Skillzzz at relocating someone elses paint picture...

Warp Factor

Getting fresh crankcase replacement air from breathers or a catch can with a breather is probably better than taking it from the compressor inlet. The supply will backflow under boost, and with it attached at the compressor inlet, all the blowby and oil mist will pass through your entire induction system.

Slow Z06

Wouldn't the line run to the turbo provide vacuum to the crankcase under a boosted condition? It seems it would take over when the normal PCV operations stop and help to seal rings under load. In a closed vacuum system like that, where in turn would it draw in the fresh air from?

Warp Factor

Minimal, unless the filters are extremely restrictive. Probably not enough to ever show up as vacuum at the crankcase.

I wasn't seeing this as a closed system. Makeup air (and blowby under boost) would pass through a breather, either on the engine, or remotely mounted, like on a catch can.

Slow Z06

My current setup with my mad paint skills lol

Overboosted

Looks good to me, I would still want something off of the valve covers too.

0C_Williams@RPM

Yes, you need to provide venting of the crankcase - either back into the system (factory) or into some catch can/filter/atmosphere. Without that, the crankcase pressure will find the easiest escape - usually the front or rear seal.

Overboosted

I would have one line off of the valley cover and one line off of the valve cover into a vented catch can if it were my setup.

Slow Z06

So even with the open filter on the oil fill cap, I should still run a line from the valve covers to the turbos or some other open source?

Warp Factor

Looks like it would work, as long as the filter on the valve cover has sufficient flow.

What's the deally-bobber coming off the tubing between the intercooler and throttle body, teed into the PCV line?

Edit: Never mind. Now I can read that it says BOV.
Is there an orifice or PCV valve in there someplace to restrict flow? Teed into the PCV system, will the BOV see actual manifold vacuum?

Slow Z06

The PCV sys has a one way high pressure, low cracking check valve. The BOV is t-d into manifold vacuum off the brake booster line.

Warp Factor

Sorry for the confusion. In the schematic in post #25, it looks like the BOV vacuum source comes from the PCV line.

There is no "flow control" valve in the PCV system (either a small orifice or a PCV valve)? Or is that incorporated into the valley cover?

Slow Z06

The only "flow control" that I have is the check valve.

C_Williams in this pic, where my oil filler filter is, do you suggest removing that and using a normal cap or retain the filter?

0C_Williams@RPM

Just the filler cap -

- in this diagram the filter is located off-board. Also note that in-line to the new filter/catch can is a check valve. This check valve maintains a closed system until WOT. At WOT the check valve opens and pressure is vented to atmosphere.

On N/A cars we run two -6 lines off the valve covers to the -10 check valve line- on boosted apps we run -10 all the way.

Charlie

EVLZ06

Not to hi-jack but this is my poor attempt at how I'm going to re-do my setup. What issues do you see?

Also it is going on my built 347 and F1A which is making upwards of 18#.

Warp Factor

You run full manifold vacuum to the closed crankcase?
How high does that get on decel?

Slow Z06

Last question. Where would the car draw in fresh air from? When I closed off the system for a test, I could hear it sucking air through the dipstick. Also, wasnt the function of the hose from the valve cover to the TB to allow fresh air in under light throttle situations when the TB closed?

Robert56@RNS

I too went vacuum pump after trying all the other methods, however, I am heavily sprayed and have a lot of blow by. The Vacuum pump can even help with better over all HP numbers. One hose into the pump and one hose out to the puke tank and the PCV system eliminated. The stock PCV system is only a partial fix to the oil ingestion issue that the LSx platform suffers.

Robert

Overboosted

I like that pump setup Robert. Any more info on it?

Robert56@RNS

I am in the process of a full write-up on the PCV system and it's down falls, along with a how-to Vacuum pump install.
http://www.robertsnitrousservice.com/vacuumpumpinfo.htm
Robert