Carburated LS1 PCV System/ Catch Can set up need help

[626Chevelle]

I have a stock LS1 Carburated with the Edelbrock/ MSD Kit. My valley tray does not have a breather like other later LS motors. I need to set up a PCV system for it but not sure whats the best way to. I don't want pressure problems and start blowing seals or have the motor running like trash. I also have a catch can with an optional breather that can be plugged. What is the best way to route this? With no PCV set up I noticed when I would pull the oil dip stick it was sucking it in. How I have it set up now is the 2 passenger side ports are plugged. Intake vacuum is going to one inlet of the catch can, and the PCV is going to the other inlet. I noticed when I have the breather on the catch can the idle would raise. When I plug the breather the idle would lower.



Ports and vacuum options:
Pass side valve cover has 2 bent vent tubes.
driver side has the pcv
intake has a vacuum port near the rear of the carb
carburetor has a vacuum port
VMS catch can has an inlet and outlet with an option to run a breather or plug it closed.
no valley tray vents or vacuums.

thanks

[67rally]

I'm not carbed, but I am running a Vic Jr. with a 4 barrel TB on top, and an air cleaner on top of that, so a fairly similar setup. These pics are from my build thread, I posted them there when I did it, because it was tough to explain without seeing the setup.

My first attempt was running a hose from the passenger side valve cover to the VMS catch can (vented), and from the catch can to the driver side cover. This did not work, I had oil pushing out from under my valve covers. Looked like this:


I ended up adding an LS6 valley cover with the build in pcv tube. I ran a hose from the valley cover to the catch can (un-vented) and from the catch can to the vaccum port on my TB. Then I ran a hose between the two valve covers, and added an oil cap with a breather/filter built in. This took care of my issues, and I do not get oil misting on the valve cover from the breather. Looks like this:


Here's a pic of the engine and hoses, the hoses run behind the engine, along the top of the firewall, behind the fender to my catch can, which is mounted next to the radiator:



I would think that you could do a similar setup. Connect the drivers side and passenger side valve covers with a hose, add an oil cap breather, and run a hose from the passenger side valve cover to the catch can, and from the catch can to the vaccum port on the carb.

[626Chevelle]

I did have oil from the valve covers and from the oil pressure sender leaking. You're a life saver! I had it wrong. I'm going to order the LS6 valley cover and let you know how things went. Where did you get the breather for the valve cover? I appreciate it sir.

[67rally]

The LS6 valley cover is the way to go. I got the oil fill breather from these guys: http://nakidparts.com/id49.html

PM sent.

[626Chevelle]

I have seen some valley plates that had a neck and a breather on it. The neck is in front of the intake centered near the steam tubes. How do you feel about using one of those instead of a LS6 valley cover?

[67rally]

I have seen some valley plates that had a neck and a breather on it. The neck is in front of the intake centered near the steam tubes. How do you feel about using one of those instead of a LS6 valley cover?

Can you post a picture of one?

[626Chevelle]

[67rally]

First time I've seen one. I think it would take care of the pressure, but I think it could be messy.

[626Chevelle]

Thanks for the quick response. I really appreciate it.

[au1991rx]

I did this.. Breather in the front of the valley cover. For me, this is actually an inlet for air because there is a bung on the rear of the valley which is connected to a catch can/PCV with a vacuum reference to the single plane intake. So the catch can pulls from the rear of the engine valley to evacuate the crankcase. I saw this on a Carcraft engine build years ago and thought it would work well enough since I did not want to put a breather on my smooth valve covers. I put in a small baffle at the back to try to keep from sucking oil. I have not cranked the engine so I cant verify it works great, but it seems logical.

[626Chevelle]

The LS6 valley cover is the way to go. I got the oil fill breather from these guys: http://nakidparts.com/id49.html

PM sent.

I was advised by someone to run a hose from one side of the valve cover to the other then add a breather to the oil filler neck. No catch can. Have you ever tried that?

[626Chevelle]

Do you think the breather is needed? some are saying no to the breather. The clean air from the catch can goes to the carb port? The passenger side is dirty air? Just making sure sorry for being a pain in the ass too.

[67rally]

I was advised by someone to run a hose from one side of the valve cover to the other then add a breather to the oil filler neck. No catch can. Have you ever tried that?

No, I didn't try that. Should be easy enough to try. Can't hurt.