Vented valley cover?
Thread Starter
Teching In
Joined: Jan 2023
Posts: 49
Likes: 5
From: St. Louis
Vented valley cover? So I'm building an LQ4 with a LS1 intake, and DBW throttle body.
I'm trying to figure out the PCV system.
Do I need a vented valley cover that LS1 use?
Or am I ok just using the LQ4 valve cover vents and sealed LQ4 valley cover....
Planning on a stock PCV routing plus catch can.
Also, if you know, could you spell out crankcase ventilation flow in one concise sentence.
(There's 500 threads with so much different info it's boggling)
I'm trying to figure out the PCV system.
Do I need a vented valley cover that LS1 use?
Or am I ok just using the LQ4 valve cover vents and sealed LQ4 valley cover....
Planning on a stock PCV routing plus catch can.
Also, if you know, could you spell out crankcase ventilation flow in one concise sentence.
(There's 500 threads with so much different info it's boggling)
TECH Senior Member
Joined: Jun 2016
Posts: 22,308
Likes: 3,625
From: Central Cal.
OK bear with me-
Pick up clean air AFTER the MAF (if you have one), but BEFORE the throttle blade (there should be a nipple for this on the throttle body).
Route this to the valve cover with unrestricted nipple.
From the other valve cover with restricted nipple OR PCV valve, route to either the catch can (see below) or the manifold vacuum nipple on the throttle body.
If a catch can is used, route from it to the throttle body as above. See catch can instructions on how to plumb it.
I hope this helps!
Pick up clean air AFTER the MAF (if you have one), but BEFORE the throttle blade (there should be a nipple for this on the throttle body).
Route this to the valve cover with unrestricted nipple.
From the other valve cover with restricted nipple OR PCV valve, route to either the catch can (see below) or the manifold vacuum nipple on the throttle body.
If a catch can is used, route from it to the throttle body as above. See catch can instructions on how to plumb it.
I hope this helps!
12 Second Club
Joined: Dec 2017
Posts: 1,034
Likes: 224
From: San Antonio
I don't think the LS1 has a vented valley cover. I know mine doesn't. You are probably thinking about the LS6 valley cover. That one does have the vent. Either way. the vented valley is not necessary. You can make it work either way. There is more than one way to set-up the PCV system. Mighty Mouse has a really nice PCV system. That's what I'm using. It took me about 10 minutes to replace the factory PCV system with the Mighty Mouse system. It's super easy.
