Billet breather

**Supersport0126** · 03-14-2012, 05:58 PM

Wanted to put a breather in place of my oil filler. 98 ls1! Is there any benifits to this besides looking cool? What if at all will it affect? noticed a little oil in my intake/tb. Pcv is brand new! Thanks

**Deviant LS1** · 03-14-2012, 06:06 PM

The PCV system either needs to be open or closed. With everything left as stock it's a closed system. If you use a breather you need to cap and remove all the lines running to the intake and TB from the valve covers. If you place just a breather and leave everything hooked up you will have a vacuum leak.

**Supersport0126** · 03-14-2012, 07:12 PM

Is it beneficial in anyway doing that or should I maybe go with a catch can?

**Deviant LS1** · 03-14-2012, 08:39 PM

Running a breather and blocking off the intake and TB from the crankcase is the only way to 100% guarantee that you won't get any oil vapor into the intake tract. But doing this also has negatives. Your oil will get dirty much quicker and you'll have have excess water vapor in the crankcase if you take many short trips and don't allow the engine and oil to fully warm up and burn vapor and containments off regularly. Also depending on how much blow-by your rings have you may get a slight oil smell or mist coming from the breather after high-rpm passes.

A catch can will help pull oil vapor from the PCV system before it reaches the intake and TB but it won't 100% solve the problem. I wouldn't run a breather just because it looks "cool."