1st-- What is their purpose?
2nd-- Why do somepeople connect a vacc hose to their intake and others put breaters. What difference does each make?

3rd-- When the vacc line running from the head to the intake is connected, doesn't the intake suck out the oil from the head?

 

1. to catch oil
2. neither really is an advantage
3. the catch can runs inline from the PVC to IM, and its supposed to bring in a tiny bit of oil

 

hmm... ....still confused

 

try searching then. its covered all the time. especially in FI forum

 

will do.

 

Air and oil usually flow from the PCV to the intake manifold, which is then combusted and the oil lowers you octane very slightly.
Put some sort of can between, and the small amount of oil will drip into it, instead of into your engine.

 

The vacuum hose on the intake actually provides negative pressure to the valvecover case under acceleration. Putting a breather filter on the valvecover eliminates the vacuum scavenging effect of an actual breather tube, but it's the only way you can prevent pressurizing the valvecover case if you're running boost.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by raene &raquo;</TD></TR><TR><TD CLASS="quote">The vacuum hose on the intake actually provides negative pressure to the valvecover case under acceleration. Putting a breather filter on the valvecover eliminates the vacuum scavenging effect of an actual breather tube, but it's the only way you can prevent pressurizing the valvecover case if you're running boost.</TD></TR></TABLE>

So is it better to have a catch can and a hose from the valve cover to the intake or what??