Can the valve cover breather be connected to the same catch can that I will connect to the pcv/oil separator box? Or, does the valve cover breather need to be connected back to the preturbo intake tubing?

 

I dont understand this concept of putting a catch can on the breather, there should not be any oil coming out of there. The breather is simply the inlet for fresh air into the crankcase. between the crankcase and the PCV valve is where a catch can is needed but most of the older motors 95 and lower have them and I belive the new motors have some sort of catch can device built into the valve cover

 

Not true. The vacuum created by the intake sucks vapors out of the space above the valves and that vapor is loaded with oil vapors.

 

You're thinking of the PCV valve, the breather is the inlet for the PCV system (do not argue with that). The only reason any oil comes out of the breather is on a boosted Honda if you have slightly bad rings. otherwise you should not have so much blow by as to cause oil to come up out of the breather. There is no vacuum on the intake tube where the breather is connected, it is after the TB.

 

Can you expand on reasons why oil comes out of there? is that the only reason? On my engine it does shoot out oil from there. How much I don't know. is there anytihng I can do to prevent that w/o overhauking engine?

 

well if the rings are starting to get bad compression will leak past the rings and shoot oil out the only hole in the crankcase which is the breather. Under boost the PCV valve is closed so that hole is not an option for the blow by to go through. otherwise, the hose or whatver you have connected there should be just slightly oily.

 

Why do you say there is no vacuum after the TB? There is vacuum created before and after the throttle body just by the principle of air moving past the open tube at the junction point--simple physics.

 

NO. Do not do this or you will blow out your front and rear main seals. The pressure will have no place to go, trust me bad things will happen.

 

there may be slight vacuum at the breather but it's not enough to overcome teh vacuum that is sucking on air. I dont think anyone here understands how teh PCV system works. The reason that tube is connected to the intake is simply to provide filtered air for your crankcase. You dont want dirt and debris getting into your crankcase. that is why you just stick the filter on there and let it suck in clean air. The only time anything comes out of there is when you are under boost and have bad rings.

 

Gruvy tune, I forgot to answer your question. if you absolutely positively need a catch can on your breather they cannot be hooked up to the same catch can as the one inline between the oil seperator (stock catch can) and PCV valve. the breather needs to be open to the atmosphere. the line running from the oil seperator to the PCV need to be sealed because it needs vaccum for the PCV system to work properly. if you need to have a catch can on your breather then get another one. the reason the say to hook up the breather to the intake of the turbo is simply because that air is filtered. believe it or not, air is being sucked though the breather at vaccum because the PCV valve is open. if you're rings are stll in good condition you can just put a little filter on the breather and that will filter the air good enough. there should be no excessive oil coming out of there.

 

thanks.
what do you do?

 

my breather has a little tube on it that runs down with a little filter on it. The PCV is hooked up to the stock location. The only thing I would consider doing is putting a catch can between PCV and stock oil seperator (which is in the valve cover on my 97 LS motor, kinda hokey if you ask me), but that's only if you're super **** about getting oil in your combustion. Remember when you're racing the PCV valve is closed so there's nothing getting in there anyway.

 

Run open loop. Connect the valve cover breather and hollowed out pcv valve to a catch can/oil breather can. The can must have an air filter on top of it. Plug the hole in the intake manifold.

Illegal as hell, but no oil vapor is going to get back into the motor.

 

well, I'd like to get some PCV action in there. so I just leave the PCV valve connected.