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I have a fresh LQ4, L92, LS3 combo with "fabbed valve covers" that have no baffling or ventilation. SEE PICS.
What is the best way to vent crankcase pressure?
I was thinking some AN fittings to cross over in back and a front fitting to a catch can. Do I have to go to intake? Or can I vent the catch can?
This will be a track only car. Thanks,
Last edited by ragtopz28; May 3, 2016 at 02:00 PM.
The best way is probably a real LS6 valley cover. I bet ports on valve covers would work just as well but I dont have any other tips about that. And get an RX catch can, I am reading lately they are the best.
Depends -- Are you running a MAF or going with a Speed Density Tune?
If you are going with a MAF you need to plumb the drivers side valve cover to the throttle body. Then I would get an LS6 Valley Cover and run it to the intake manifold (or run a catch can in between the valley cover and the manifold).
If you are running a speed density tune, I would do a screw in breather where the oil fill cap is. Then run an LS6 valley cover with a catch can. You would run from the valley to the catch can, and then from the can to the intake manifold. Block off the throttle body connection. This is what I currently do.
Depends -- Are you running a MAF or going with a Speed Density Tune?
If you are going with a MAF you need to plumb the drivers side valve cover to the throttle body. Then I would get an LS6 Valley Cover and run it to the intake manifold (or run a catch can in between the valley cover and the manifold).
If you are running a speed density tune, I would do a screw in breather where the oil fill cap is. Then run an LS6 valley cover with a catch can. You would run from the valley to the catch can, and then from the can to the intake manifold. Block off the throttle body connection. This is what I currently do.
It will be a SD tune. Don't really want to change valley covers at this point.
My current car in sig has a "cap" filter and all the other stock LS1 valve cover ports going to another filter...I have to put wrist sweat bands on both filters due to high rpm oiling.
That's why I was thinking just vent to a catch-can and then vent the can so not to run to intake. This will be short 7K rpm pulls down the 1/8 and 1/4 mile only.
I'd just run 10AN lines off the valve covers to a good breather can, change your oil more often and ditch the PCV since your a track car. Oil vapor into the air/fuel mixture? I know it's how the engineers designed it but somehow I feel it was more for emissions than anything else.
Track only car? If the exhaust setup allows check out crankcase header evac kits.
Catch cans will work or they won't, IMO there isn't really a sort of working option.
PCV with a working catch can should lead back to intake. No drawback with a properly working system. PCV without a working catch can is garbage and worse than nothing beyond stock setup.
Vented can is same as breather on fill cap except now you added weight, clutter, and potential points of failure.
Header evac lets the exhaust draw straight from valve cover and out the exhaust. No oil returned to intake, no crankcase pressure, and it works when you need it most for high rpm duty.
With the LS6 valley cover, you'll only need to get air into one valve cover. As the factory used the right cover, so did I. Filtered fresh air from the throttle body gets plumbed to the valve cover, gets drawn out through the valley cover which has a simple air/oil separator built into it.
I used -6 AN line.
As you have a LQ4 block, you won't need to remove the thing in the block that's in LS1 motors.
Last edited by Paul Bell; Jul 17, 2017 at 09:11 PM.
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Nobody got nuttin? 
How/Best way to vent this thing... 
