wont you loose boost pressure through the crankcase vent on the vavlve cover if you dont have a cath can?

 

no, pcv valve closes w/o vacuum.

 

yeah but the tube that connect from the valve cover to the intake tube or charge pipe right before the tb....is there a one-way valve there somewhere also?

 

the tube from the valve cover should not be connected to the intake after the turbo. either connect it before the turbo, or better, add a valve cover breather filter.

 

 

A crankcase vent attaches to the the block, not the valve cover.

JK with the

 

It depends on the design of the engine, PCV (positive crankcase ventilation) can be located on the block or on the valve cover. crankcase vapor can pass through the valve cover through the oil galley passages in the cylinder head. That's how oil drains down to the crankcase.

 

Im using a catch can which connects to the valve cover vent
and also to the PCV in the back of the block.

 

yeah, that doesn't do much of anything. the valve cover is where air ENTERS the crank case. Seeing how there isn't any oil in the air to catch, it isn't doing much. If you are catching oil, that means your getting blow by gas and your rings might be going.

 

the oem tube goes from the valve cover to the intake tube. the air from the intake tube sucks the pressure out of the valve cover i thoght.

 

you have it backwards. the tube from the intake manifold sucks air from the crankcase (through the pcv). the valve cover is just an inlet. it should be setup like this:

 

So it sucks through the intake tube goes through the oil passages and out the pcv for circulation.

 

yep.

 

mine was on the head, not block, just left a piece of hose on it, ghetto style

 

flow of the air goes from the intake through the hose and into the valve cover......

 

never knew that

 

That pic looks wrong.

The intake tube has a higher preassure than the intake manifold, so the air is pusher through the valcve cover, through the head, through the block then through a really shitty filter, the output from that filter is conected to the PCV valve which then conects to the intake manifold after the throttle plate.

If I were to add a catch can I think the most productive place would be between the stock filter and the PCV valve.

-Dustin