Boost into the crankcase is bad
Originally Posted by Standing Room Only,Jun 8 2006, 11:42 AM
Haven't been able to speak with "Billy" at Comptech, but at this point I'd agree that the stock PCV valve (if that is what Comptech is relying on) isn't up to the task. So - what kit? The "mini" vent kit?
Hey guys
Sorry to bring up an old post.
I'm new here. Although I don't have an S2K, I was wondering if you could help me out. I have a 95 turbo integra RS, with a greddy turbo kit. I just installed a greddy catch can, but I know its not enough in helping relieve crank case pressure. I'm interested in purchasing a set of these krank vents but I have a few questions.
1. I know one of the krank vents fits between the PCV valve and the IM. Where does the other krank vent fit? Where the breather is? If I have a filter where the breather line used to be, just fit a krank vent on there inline with the filter?
2. I'm still confused how this will relieve crank case pressure. When on boost, the crank case will still get pressurized, and the only way you can relieve that pressure, is thru the PCV valve? Well, that valve is still small, so how can it relieve pressure correctly with these krank vents? Wouldn't it be better to purchase this: http://www.theoldone.com/components/breather/
since the fittings behind the block and will relieve crank case pressures correctly?
Here's a pic of my setup. Any help would be greatly appreciated.

As you can see, I have my catch can going to the IM and PCV valve.
Sorry to bring up an old post.
I'm new here. Although I don't have an S2K, I was wondering if you could help me out. I have a 95 turbo integra RS, with a greddy turbo kit. I just installed a greddy catch can, but I know its not enough in helping relieve crank case pressure. I'm interested in purchasing a set of these krank vents but I have a few questions.
1. I know one of the krank vents fits between the PCV valve and the IM. Where does the other krank vent fit? Where the breather is? If I have a filter where the breather line used to be, just fit a krank vent on there inline with the filter?
2. I'm still confused how this will relieve crank case pressure. When on boost, the crank case will still get pressurized, and the only way you can relieve that pressure, is thru the PCV valve? Well, that valve is still small, so how can it relieve pressure correctly with these krank vents? Wouldn't it be better to purchase this: http://www.theoldone.com/components/breather/
since the fittings behind the block and will relieve crank case pressures correctly?
Here's a pic of my setup. Any help would be greatly appreciated.

As you can see, I have my catch can going to the IM and PCV valve.
Originally Posted by Sideways,Jan 20 2007, 05:31 PM
The one Krankvent keeps the PCV from flowing backwards and the other would go next to the little filter.
Ok sounds good. I still dont understand how these krank vents will relieve crank case pressure especially when boosting. Boosting will increase the crank case pressure by a lot, so the only way its relieved is thru the PCV. Even with the krank vent, extra crank case pressure will have to go thru the PCV....
The KV only creates a vacuum when there is vacuum in the intake manifold (the PCV KV opens and the front valve cover breather KV closes). You put the catch can in this line to get rid of all that oily gunk before it enters the intake manifold. Under boost conditions, the PCV KV closes and the front valve cover breather KV opens, relieving any blow by pressure, but not creating any vacuum. If you want a vacuum under boost, you need a vacuum pump or some other form of vacuum generator. On my current build, I'm thinking of using the air pump to switch on under boost and evacuate the crank through the front valve cover KV.
Ah makes sense. Let me see if I got this right. The KV prevents the PCV valve from opening. Therefore, the only way crank case pressure is now relieved, is through the breather filter...under boost conditions.
Hmmmm although the opening on the breather filter is bigger than the PCV location, is it sufficient in relieving crank case pressure? Now it seems all that crank case pressure/gases will be vented in the atmosphere. Whew that must smell pretty bad under boost haha.
So what you're saying, although crank case pressure is relieved, it might not be enough, so a vacuum pump can be used to relieve any other crank case pressure and blow by.
So in essence, it might be better to use the endyn setup, as the design on that is supposed to relieve any crank case pressure & blow by.
Hmmmm although the opening on the breather filter is bigger than the PCV location, is it sufficient in relieving crank case pressure? Now it seems all that crank case pressure/gases will be vented in the atmosphere. Whew that must smell pretty bad under boost haha.
So what you're saying, although crank case pressure is relieved, it might not be enough, so a vacuum pump can be used to relieve any other crank case pressure and blow by.
So in essence, it might be better to use the endyn setup, as the design on that is supposed to relieve any crank case pressure & blow by.
You can have it create a vacuum without the need of a vac. pump if you plumb the line back to the inlet side of the turbo (where your air filter is located). It will more so suck the blow-by and not so much create a vacuum but it will keep the crankcase from being pressurized since the amount of air the turbine will attempt to pull in will be much greater than the total blow-by that can be generated.
FPerra has his car set up a bit differently from what is recommended by the manufacturer. He has a breather filter on his KV on the breather side so his cannot create a vac. in the crankcase which is why he was talking about a air pump.
FPerra has his car set up a bit differently from what is recommended by the manufacturer. He has a breather filter on his KV on the breather side so his cannot create a vac. in the crankcase which is why he was talking about a air pump.






