john.tempest

Hey everyone, so need some help.

The LS is finally installed in the 240z and I need some help in regards to catch can / re circulation setup.

I am posting a couple pictures of the DR 525 valve covers that I have on the build and need some help with running lines.

So my questions are as follows:

1. Can you guys comment or possibly draw me a diagram that includes where lines to / from each valve cover go? I am still a little lost on this topic and don't understand the re circulation of the air from the valve covers to the intake, or where I would integrate a catch can, if I need one, or if I need breathers?

2. The DR525 valve covers are different then the stock LS3 covers. There are two threaded AN fittings on the driver side and only the one outlet that goes to the intake tube on the passenger side valve covers. Does anybody know what size of AN fitting I would need for these?

3. I think i would like to go with a Mighty Mouse setup, perhaps they can chime in?

Thanks everyone.

john.tempest

Bump, need some help guys

kingtal0n

iTrader: (1)

I dont know how much you already understand about PCV so I am not sure where to jump in here,

the crankcase systems in automotive applications that are NOT running vacuum pumps generally have two ports in the crankcase. One is on one valve cover and the other is on the other valve cover (but we can put a port anywhere we want; for example LS-6 valley cover has a port in it. Its like adding another hole in the crankcase. Usually we just want 2, so no, I did NOT use the LS-6 valley cover in my daily/Turbo LS swap for example).

One side will have a check valve, this is the "pcv valve". The side with the check valve is typically the intake manifold vacuum signal, since during boost you can imagine the check valve will shut tightly against the intake manifold boost signal, this should help you visualize both the direction of flow and necessity of the check valve on that side.

The other side is a simple vent tube, which often extends from the other valve cover to some fresh air source, usually the post-air filter tract is used. This applies even in OEM turbo applications as this is the only source of vacuum during boost (precompressor, post air-filter tract).

The way it "works" is, during engine vacuum the intake sucks on the check valve side valve cover crankcase port, and fresh air is replaced into the crankcase from the other fresh air source tube (other valve cover) to replenish what the intake manifold sucked in. If you blocked the fresh air port the intake manifold would pull intake vacuum on the crankcase and it would probably damage an oil seal permanently or pull a bunch of foil into the intake, so this is a common port/tube to replace/wash/inspect.

During boost the check valve shuts and flow is reversed, now the checkvalve side is acting like a "wall" and the only vacuum source is the compressor inlet, which is tied to your fresh air source. This is the OEM manufacturer method, once again, for all turbo cars in the world pretty much.

ss4chad

iTrader: (26)

Try this;

https://ls1tech.com/forums/generatio...fo-needed.html

It has pictures and everything!

Chad

MIGHTYMOUSE

iTrader: (59)

all i need to know is what application this is. street, street/strip, road race. etc. and how much power you are looking to support.

it sounds like you want to run a pcv system, which is most popular, so we would start with that and work backwards as needed.

the aftermarket valve covers are usually harder to work with than stock for these situations, because they are often built for a purpose not reviewed by the buyer or seller prior to transaction.

john.tempest

Hey there, thanks everyone for the help.

Mightmouse

So yes, would like to retain PCV Valve. It is going to be primarily street driven, but will definitely see some 1/4 track time on the weekends.

I am building for 600 HP right now, might get more down the road, but 600 for right now.

The valve covers aren't aftermarket, well I guess maybe they are? They are off a GM performance crate engine, the DR 525. They have two AN fittings on the drive side valve cover, not sure what size.

00pooterSS

iTrader: (40)

Everything you need to know is in this thread posted above.


You need on valve cover hooked to the vacuum source (intake manifold) and the other valve cover hooked to a fresh air source after the mass air flow sensor (either the port on the throttle body before the throttle blade or in the intake tube before the throttle body.

I would hook the driver side cover to the catch can and then to a pcv and then to the intake nipple

Then figure out how to adapt an AN fitting down to a 3/8 hose and hook it to the fresh/filtered air source.

MIGHTYMOUSE

iTrader: (59)

the LSF mild system i have includes the pcv control, and you would need to make the can connection to one of your v/c ports, and one port on opposite side to atmospheric reference, after maf sensor if possible.

john.tempest

Mighty Mouse, if you give me a price on a kit, shipped to Canada, with what I need and a diagram of all the connections and what goes where in terms of venting, lines, from which valve cover and intake manifold, etc I would be greatful.