circuiticon

I checked out the sticky here, but wasn't exactly sure what I should do.

Basically, I have an LS1 with an LS2 intake mani (bought it that way) swapped into a tube frame car. Not sure what I should do with PCV/catch can routing:

circuiticon

bump!

BudRacing

iTrader: (3)

You effectively have a draft can which is basically a passive vent. I'm not sure if that's why you have oily residue on top of the intake manifold, but it could be related. If it's street driven more often than it's track driven, I'd probably rig up a PCV with a catch can if it were mine. The PCV helps to remove water and other such contamination from the oil. However, if it's just a weekend thrasher and you change the oil often enough then you're fine leaving it as-is. I'm assuming it's been that way since the intake was swapped, so your intake is probably very clean, which is obviously a good thing.

If you are to rig up a PCV catch can, you're going to need a can that's sealed (or one of Mighty Mouse's with a VALVED breather that is closed under vacuum).

The line to your valve cover from the top of the throttle body is correct. That is the fresh metered air inlet.

The capped line from the valley cover should go to the top port of a catch can which typically has some sort of mesh or filter to help separate accumulated vapors from the air stream. The outlet of the catch can should go to the capped port on the intake manifold.

The older style PCV valve on the driver side valve cover can either be capped or tee'd into the inlet side of the catch can (top port). Or you could leave the valley cover port capped and run the driver side line to the top of the catch can.

circuiticon

I'm not aware of a PCV on the driver's side VC...unless it's internal? I just have a hose there that goes to a catch can which is VTA.

So the way I see it, I need to do one of the following:

1. Put a closed catch can on. Input would be the valley cover, output would be the intake mani behind the TB.
2. Do #1, but with a PCV valve (pn please?) between the valley cover and the can.
3. Run the valley cover into my driver's side catch can.

I'm not sure which way to go, but clearly it being looped is no bueno, correct?

Depending on which of the above routes I take, do I need to do something different with my driver's side catch can?

G Atsma

There is a whole sticky on catch can routing at the top of this section of the forum. It might be able to help you.

circuiticon

Yeah, I read it (noted it in my first post), but I'm still not clear.

G Atsma

OOPS! Sorry, must have overlooked it somehow. I hope you can resolve it soon!

dreadpirateroberts

iTrader: (1)

just cap the driver side valve cover port.

later year model LS motors do not use a PCV valve. you do not need to use it.

if you have an LS6 valley cover, you should have an air/oil separator in it. you can just use a line from the valley port to the intake manifold and just run it. I am sure there is an LS2 part number for the hose you can use. You don't NEED a catch can.

if you do decide to run a catch can, run one as budracing described. airflow should be from fresh air intake to crankcase to valley cover to catchcan to intake manifold.

BudRacing

iTrader: (3)

I'm not sure about the exact origins, year model, etc of your LS1, but early LS motors had a PCV valve on the rear of the driver side valve cover. The LS6 had a revised PCV function through a baffled orifice in the valley cover and the DS valve covers were capped. It appears you have both because someone upgraded the valley cover to the LS6, but the valley cover port is capped and the valve cover is vented through your draft can. You can use either or both PCV outlets to serve as vents to the crankcase.

#1 is correct.
#2. The output of the valley cover does not require anything more than hose to the can.
#3. You could run the valley cover port to your current can setup, but it would be of no benefit as your draft can seems to be setup properly.

nhra686

Put a vacuum pump on it and reap the benefits

dreadpirateroberts

iTrader: (1)

reap the affect on your wallet, too.

circuiticon

So if I do #1 (Put a closed catch can on. Input would be the valley cover, output would be the intake mani behind the TB.), should i remove the catch can from the driver's side and just cap off the port on the valve cover?

Or should I remove the breather from the catch can and have the driver's valve cover and the valley both go into the catch can, then recirc the "clean" air back into the intake mani behind the TB?

Also, if it helps, my LS1 is from a 2004 GTO, so I believe it has the LS6 valley cover (even though it has the wrong intake mani - from an ls2).

I plan on upgrading my mani to a FAST 90 at some point.

circuiticon

Sounds expensive.

Got a link to a decent kit?

BudRacing

iTrader: (3)

Correct.

Also an option. You could use the threaded (I'm assuming it's threaded) breather port as the input for the can with a 90* barbed 3/8" fitting, but I'm not sure if there's a decent filter element in the can you have. You'll want something for the oil particles to collect on to drip into the can since they're mostly in a vapor state when entering the can. Reusing and adapting your existing can is probably the most cost-effective option.

I'm running this inexpensive can: https://www.ebay.com/itm/LS-Catch-Ca...5ZNz2R&vxp=mtr

Easy install, well made, probably won't find a new one cheaper. In the 2nd photo in the ebay listing you can see the filter portion under the removed lid.

5.7stroker

iTrader: (36)

Get a mighty mouse catch can and be done with it.

https://www.mightymousesolutions.com...en-f-body-mild

You want a can that does NOT:

-have oil build up in the intake
-hurt performance
-have increased pressure that causes seals to blow
-result in smell caused by off gassing into the engine compartment due to use of breather filter