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I ran lines from each valve cover to a T that went went into the waste gate dump tube, so when the waste gate opens it pulls vacuum from the valve covers.
so, those that have draw through type cans that see vaccum in non-boost throttle areas, how much oil do you get in the can? say every oil change if its around 3k or so
you have to consider if it is enough breathing to adequately vent your power level
how will they fit the valve covers you have
will you be ok with oil leaking out of them down onto the covers and exhaust
will you be ok with the full time crankcase fumes going into your engine bay, and nose
will you be ok with your oil becoming dirty more quickly (lack of pcv system or scavenging)
i think some sort of PCV system is useful. once the oil is hot enough to boil out any water (just one byproduct of combustion which reaches the oil via blowby) it's gotta go somewhere.
i'd rather not have combustion byproducts acidifying my oil and attacking my bearings.
the added bonus of having a proper catch can is pulling any aerated oils and hydrocarbons out of the PCV line and preventing it from entering the intake and causing detonation.
Here is my setup, probably something similar on the MM website, since I bought the can and some pieces there.
My setup uses a modified AC drier bracket.
Vents out through the oil fill hole, for the dirty side, with a -12 line I believe, again got the fittings for this from Mighty Mouse. The PCV valve is in the can, and vacuum is provided by the hose running to the factory location on the intake manifold.
For the clean side, I used the factory fittings that was the dirty side on the back of the drivers side valve cover. I then put a small K&N filter on with a 3/8" opening that matched the factory tubing there. You can see it over by the brake master cylinder.
I removed the little pipe, and filled the section of the throttle body with epoxy where the factory PCV drew in its metered air for the clean side, through the throttle body. You can only do this on speed density cars, with a MAF car my set up would introduce unmetered air into the engine, and that would have it running lean. If you do not do this, with a turbo car, it will boost the crank case, which will cause lots of problems, like it will push oil back up your turbo drain line back into your turbo.
Bumping old thread. Currently running 3/8 hoses from each VC to a catch can that is vented at the top. Getting tired of fumes in my car so I'm looking at revising the setup. 7875/6.0, 8psi for now.
Here's what I'm thinking...
Open breather filter on the oil fill cap. Each valve cover nipple has a 3/8 line to the sealed catch can (filled with coarse steel wool). Top of catch can has a 3/8 line running to intake manifold with an inline check valve.
Under cruise/vacuum, intake manifold sucks vacuum through the crankcase and catch can, with the breather on the oil fill providing make up air.
Under boost, the check valve closes so the crankcase isn't pressurized and any blowby is vented out of the breather. Once I let off the gas, vacuum pulls the vapors out of the crankcase and the can.
My concerns:
-The oil filler breather is pretty close to the passenger side valve cover nipple, so there may be some short cycling there.
-oil filler breather necks down to 3/8 which may be a restriction on the make up air side-engine will still have blowby during boost, vented out the breather
-unmetered air means tune will be affected, does this matter since I have no MAF? It's a TermX using a standard MAP.
you cannot have unregulated vacuum application to the crankcase
correct on both your concerns
How is the ideal PCV orifice calculated?
I could cap the passenger VC nipple so the short cycling issue is eliminated, which forces the fresh air drawn through the oil filler breath to go through the entire crankcase before exiting the rear of the driver's VC. Since I'm effectively halving the amount of air that is able to exit the crankcase, that would help with the regulation issue, but I don't know if it's too little or too much.
For those running a turbo setup with no filter due to packaging issues, where are you grabbing your fresh air source from? I have a breather on the filler cap now which is managing the PCV nicely under vacuum, but under boost the blowby is venting out the breather and momentarily sending fumes up to the cabin. Minor annoyance but enough to be a pain. Perhaps drill and tap the flange in front of the impeller for a fitting?
01-07-2017, 01:42 PM
