LS PCV Routing for Ultra4

[RM222]

After the Montana Big Sky 200 in May and a couple short races that broke out with friends in Idaho following week, there's oil seeping from the front and rear main seals on my LS3. It's not dripping oil, it's just stuck on the front and rear of the engine and oil pan in a fairly large area. Maybe I'm making something out of nothing but I would like to get ahead of this if it results in not having to replace the main seals. The engine temps spiked @ 250° during the Montana race , the highest I've seen so far. The oil on the dipstick was a little lower but nothing to be concerned about. I changed the oil with 15W50 AMSOIL Dominator the week before we left. This is the first time I've run AMSOIL because that's what my local sprint car shop had it in stock.

Anyways, it got me to looking at my PCV system because I'm concerned the crankcase pressure is possibly forcing oil out the main seals. My crankcase is vented to atmosphere via 1/2" rubber hose exiting both valve covers, to a T-fitting, to a catch can with a filter on the top. No PCV valve is is being utilized. I'm NA with a Holley Terminator Max EFI, Trail Blazer SS Intake and DBW TB (GM PN 19420707) which doesn't have any ports. I don't use a MAF, Holley uses an internal MAP and an IAT in the intake tube and the wideband O2 for engine management.

Here's my setup:

What are your thoughts and experiences regarding PCV routing for an Ultra 4 car?

 

[Bebop]

Don't T the lines, get bigger lines, a bigger catch can and run them direct to it. Re-use your existing catch can for the front diff only. You don't want to be mixing these anyway.

 

[mobil1syn]

-8 off each cover to a combined catch can. 3 sides and down on the catch can

 

[SLOWPOKE693]

Personally I would run -10 or -12 hose off the valve covers to a catch/breather tank. -8 is a bit small for a race engine IMO

 

[cdemart2]

I run -8 hose from each valve cover 3 sides and down to atmosphere. no catch can.

 

[Wisconsinite]

I ran -8 hose from each valve cover 3 sides and down to catch can, to a filtered outlet.

 

[HYDRODYNAMIC]

You might have restriction at the valve cover using factory barbs. Some have restrictors for vacuum for PCV use. Some are open. Either cut them out and weld on an AN of equal size to hose or port the valley cover. Valley cover is less likely to fill with oil. Valve covers are more likely to hold oil and blow into the lines. A line full of oil has a lot more restriction than a clean line when you are trying to move air.

 

[RM222]

Thanks everyone. I'm going to work on adding bigger breathers, separate lines and catch cans to my system then.