PCV on a boosted engine???

[LS1NOVA]

Anyone have a good setup?

Needs to be an actual vacuum system. I dont really want just a vent system, Id like to use vacuum to pull the vapors and keep the oil cleaner.

[shmoov69]

The only way that I know of is to run it into the intake behind the air filter(s), but before the turbo(s). But I do not have one and am not sure if it will work decent enough or if it will "clog" the system with oil vapors and such. Another route is a devoted vacum pump system.
Any others?

[Mike Norris]

Not sure what intake you are using, but with the stock LS style manifold I run the standard LS PCV system with a one way check valve between the PCV valve and the intake manifold to keep boost pressure from getting into the crank case.

I am sure you can do the same with a carb manifold with a set up like John Parsons or with a remote PCV valve.

Of course I would install one of my catch cans also to keep any vapors out of the intake :cheers:

Hope this helps.

Mike Norris

[LS1NOVA]

Victor Jr intake, valve covers have none of the factory ports, throttle body port gone, etc. I was thinking running 2 -10 lines from the valve covers to a catch can then to the inlet of the turbo. Fresh air from a vent on the valve cover with a one way valve??

[Blown353]

Victor Jr intake, valve covers have none of the factory ports, throttle body port gone, etc. I was thinking running 2 -10 lines from the valve covers to a catch can then to the inlet of the turbo.
That setup as described will catch all oil vapors emitted from the engine and suck them back in and reburn them... but it will not provide constant fresh air circulation through the crankcase to help keep the oil clean and actively suck out combustion blowby and contaminants.

To properly ventilate the crankcase and keep the oil clean requires that fresh air be constantly circulated through the engine... that's what a PCV is for.

Also, a good PCV will seal on it's own under boost-- but as Mike mentioned it isn't a bad idea to add a check-valve in line for additional reverse-flow protection.

Also like Mike said, adding an in-line air/oil separator (like his good catch can, AMW also makes a good one) is an excellent idea. Oil in the intake charge helps promote detonation.

I have my blower engine set up with large filtered breathers on baffled stands in each valve cover, and a PCV in the intake valley that is baffled. The PCV runs through an AMW catch can prior to going up to the plenum, it does a great job separating the oil vapors and the intake plenum is extremely clean even after several thousand miles. The PCV is sourced off a Buick Grand National, easy to retrofit because it has hose barbs on each end and as the OEM application involved boost it seals very well. You can't blow back through it either with your mouth or with an air compressor.

[Mike Norris]

"Victor Jr intake, valve covers have none of the factory ports, throttle body port gone, etc. I was thinking running 2 -10 lines from the valve covers to a catch can then to the inlet of the turbo. Fresh air from a vent on the valve cover with a one way valve??"

The setup you are describing is more of a breather package then a PCv system. In this case you would not want it going back to the intake tract as it would most likely allow oil to get there anyhow. I have attached a picture of a billet 3" can we have used for that in the past.

If you do not have a baffled source for the PCV system such as the stock valve covers use, you could use the LS6 style valley cover from a 2004 Vette as Blown353 has. This works very well to say the least. If the area for the PCV source is not baffled initially it will tend to get a lot of oil into the hose.

The GN piece is another option for sure, but I have not used one. I try to stay with all LSx pieces and a catch can on these engines as it is just my preference.

Hope this helps.

Mike Norris

[LS1NOVA]

So run the whole pcv system through one little hose off the valley cover?

[Mike Norris]

"So run the whole pcv system through one little hose off the valley cover?"

Yes sir pretty much. The factory 2004 LS6 valley cover incorporates the PCV system in it and it just uses a short "U" shaped hose from the valley cover nipple to the inatke behind the throttle body. You can run the hose from the valley cover nipple to a fitting at the intake near the base of the throttle body and some kind of catch can in that line to prevent any oil vapors from getting into the intake manifold.

You do need to be sure that you have some kind of breather or breather syetm on there also so the car does not pull full vacuum on the crank case. This will cause either the front or rear seal to go bad as well as some noise from air passing by the seals. You can just add a breather filter to the oil fill or a remote breather as you descibed with the two lines from the valve covers into a catch can.

Hope this helps.

Mike Norris

[LS1NOVA]

That sounds good. Do I also need a one way valve in the hose from the valley cover to the intake?
Thanks for the responses.

[Mike Norris]

"Do I also need a one way valve in the hose from the valley cover to the intake?"

I definitely would on a forced induction car. Just one more way to help keep things in check.

Mike Norris

[kenhaw]

Sorry for jumping in here but I have a similar question.
My setup is two breathers in the right valvecover and the pcv in the left valvecover connected to vacuum in the lower part in the back of my carb. Will this setup work ok if I install a checkvalve in this pcv line?
I also run a procharger.

Thx

[big_G]

Yes, but I don't use a check valve. The minimal leakage through the PCV valve under boost is insignificant.