Posted 22 August 2012 - 12:46 PM
*UPDATE: With some trial and error I have modified this setup a little since this writeup. I have kept the smaller Krank Vent in place that replaces the stock PCV valve between the front of the VC and the TB, but I removed the fatter one between the rear of the VC and the turbo intake tube and now run an oil seperator in between. This is due to the lack of a need for a check valve in that location, there is constant suction there and never any pressure on that line.
This writeup features the KrankVent system, from ET-Performance. I love these kinds of mods because they are simple, and WORK well. KV's have been around the Starion scene for a long time, but I had never installed them before.. *Update: This is the Turbo "mini" kit.
I looked into KV because lately on hard runs my PCV would fail and allow boost into the crankcase. The bottom end is also a little worn out, smoked a little bit, so.. getting some blowby. At the time, the breather setup was similar to stock: I had the stock PCV valve on the valve cover and a catch can that drained to the oil pan on the turbo intake side, with lines running from the back of the valve cover and to the turbo intake tube.
The idea is that the turbo intake tube provides suction to pull pressure through the catch can from the crankcase (back of valve cover), and from the intake though the PCV under vacuum. The KrankVent parts just make the system work the way it's supposed to. The system consists of two one-way check valves, one larger than the other. They are sealed, precision high flow valves that allow zero opposite flow up to something over 75 psi or something. It's on the website.One KV connects inline with the PCV valve hose (basically replaces it), the other connects between the turbo intake tube and the rear valve cover breather port. You take take factory oil seperator can out, and plug the line running down to the oil pan.
Doesn't get any easier than that!
Now what happens is the KV valves only allow pressure to leave the crankcase, creating a constant vacuum situation. The vacuum is strong enough to suck the dipstick back down into the tube with a loud HISSSSSS-THUPP. No matter whether you are boosting or not, vacuum is maintained in the crankcase and there is a suction on the pistons coming down. The car stopped smoking almost completely (lol), the effect even minimizes any oil leaks because of the negative pressure on all the seals in the motor!
I replaced the PCV valve with this 1/8NPT to 3/8" hose fitting for more flow. Some people drill out the stock one, some leave the stock one alone.
This is only screwed hand-tight but you get the idea.EDIT* I have since removed this part as it was not necessary.
This is the fatter KV attached to the turbo intake tube. Notice the flow direction, it's critical.
I left a small length of clear reinforced hose to see if oil was being sucked in... so far, nothing. I reused the AN fittings from the catch can I had before.
You can see the line running from the rear of the valve cover up to the intake tube, the KV is hidden under the turbo piping.
There it is. This is the fatter KV.
This is the smaller KV on the intake side, you can see the fitting that I replaced the PCV with. Notice flow direction... Works like a charm.
Edited by Fuze, 08 September 2014 - 10:38 AM.