Crankcase evacuation using turbo intake.

[ShadowFromHell]

I'm in the design phase of building a proper crankcase evacuation system for my CSX. In vac I'm going to use a typical PCV setup. In boost I want to use the turbo intake. I searched and found a couple threads referring to using a slash cut pipe in the intake to take advantage of the Bernoulli principal. Sounds like a great idea. Does anyone have a pic or diagram on how to properly do that? If I copy how guys set up the tube for exhaust evacuation will that work?

Thanks

[GLHS60]

Are you going to evacuate octane reducing crankcase vapors directly into your engine's air intake??
I like to keep them totally separate by totally eliminating the PCV on all my 8 V engines.
Have you considered crankcase evac using exhaust??

Thanks
Randy

[puppet]

If you have to run it back into the inlet side you should provide a catch can and another filter to scrub the crankcase gasses before the turbo eats them. As Randy points out this isn't ideal but doable. You shouldn't need any fancy slash cuts here because the engine will be pulling on it pretty hard. The slash cut pipe is done in the exhaust to help create a needed pressure differential. Even with that we just see about 3-5psi pull on the block.

[ShadowFromHell]

Im planning on a catch can, and will also be using a pcv valve system for when it is in vac. Just trying to figure out my "boost" side. What kind of filter would I use to scrub the gasses? Im not opposed to putting it in the exhaust, but it would be a lot easier to put it in the intake lol. I also have very short exhaust. I only have 36" of exhaust and that's only because I need 18" before and 18" after for the WBO2 to read properly.

[Reaper1]

I wish the T.O.O. forums still existed because that place had this covered up, down, and sideways. This isn't the *exact* answer you were looking for, but it might help:

http://www.theoldone.com/archive/pcv-breather.htm

[DoubleD]

Take a look at this thread:
http://www.turbo-mopar.com/forums/sh...I-s&highlight=
I finally have a handle on this set-up and it is working really well. This is a TIII car, but the principles are the same.

[ShadowFromHell]

I've looked over that thread many times. I think I'm going to try exhaust evacuation coupled with a pcv system. Check valves to separate the two. Here is my question though, in all my research over the years one of the problems with exhaust evacuation is pulling to much vacuum. What if I put a pcv valve inline with the exhaust evacuation? Part of what they do is limit the amount of vacuum to safe levels right? So any reason one wouldn't work to regulate the vacuum with a exhaust evacuation setup?

[ShadowFromHell]

Exhaust vac is in and working! I'm going to start a new thread with all the info and pics. I'm excited, I've wanted to try this for years and finally got off my butt and did it

[Ondonti]

Only problem with exhaust evac pulling too much vacuum is if its from the head and your head fails to drain oil. Had that happen when I ran two valves, one on each head and 3.0's have poor drainback with lots of casting flash in them. Just run 1 valve on daily driver that tee's to both heads. I would also add a better check valve to your PCV.
A lot of engines have to run the breather directly to the crankcase through the block or top of the oil pan.

[tryingbe]

Exhaust vac is in and working! I'm going to start a new thread with all the info and pics. I'm excited, I've wanted to try this for years and finally got off my butt and did it

Please do.

[ShadowFromHell]

Anyone ever added a port to the pan or block? I would much rather pull from the pan then the VC. That way the oil returning to the pan isnt fighting with the evac system. Instead it would be helping the oil return.

[Reaper1]

Yes, people used to add ports to the fuel pump block-off back in the day on non-CB's. They would also run a hose between the block and the head/valve cover to balance the pressure between the two to help drain back.

[ShadowFromHell]

Ya I know about the block off plate trick but I am running a CB. What about tying into the turbo oil return line? I had thought about that but am afraid it would cause issues with turbo being able to drain properly. I am also running a Shelby VC I don't want to remove or add ports too...

[Reaper1]

So, there is still enough meat in the block skirt that you can drill/tap for a fitting, or use a through bulkhead style. Instead of running a standard oil fill cap, use either a modified one that allows for venting.

[johnl]

I've looked over that thread many times. I think I'm going to try exhaust evacuation coupled with a pcv system. Check valves to separate the two. Here is my question though, in all my research over the years one of the problems with exhaust evacuation is pulling to much vacuum. What if I put a pcv valve inline with the exhaust evacuation? Part of what they do is limit the amount of vacuum to safe levels right? So any reason one wouldn't work to regulate the vacuum with a exhaust evacuation setup?

Look at Jegs or Moroso; they sell a regulator, 3/4" NPT, which is just an adjustable flutter shim stack that is pulled open by vacuum to allow air into the VC. It is 1" OD so one of those small K&N crankcase evac filters can fit over it to ensure that your evac system does not pull dirt into your engine.


Edit - could be 1/2" or even 3/8" NPT

[Ondonti]

Ya I know about the block off plate trick but I am running a CB. What about tying into the turbo oil return line? I had thought about that but am afraid it would cause issues with turbo being able to drain properly. I am also running a Shelby VC I don't want to remove or add ports too...

Don't mess with turbo oil returns. Those need to be pampered.

[GLHNSLHT2]

alll the 90+ turbo returns had T's in them for crank case drain back from the air filters. At least on the 8v motors.

[Ondonti]

I would really like to find a better exhaust check valve. I have two inline and they still don't hold. One is a moroso (they fail completely eventually) that reverberates so much that the check opens and closes constantly which lets stuff go "out"
Maybe it needs a stronger cracking pressure.

[Reaper1]

Are you talking about the EGR ones or something different? I can't remember right now...

[Ondonti]

Are you talking about the EGR ones or something different? I can't remember right now...

My phone is broke btw, no phone till the 20th.

I did some research on it and it sounds like the Ford valves have almost no cracking pressure while the GM air pump (smog) check valves are supposed to have higher cracking pressure. People also noted an incredibly high variance in cracking pressure between the "same" valves. Then I also wonder how close random aftermarket manufacturers get to the OEM intended cracking pressure (whatever that is).

I did find that the extra check valve I put in a few months ago on the PCV was backwards, so zero function there. I only dug in because when the rain came I noticed I was leaving a trail.

I bought a GM style valve today. Its the type that will screw onto my port. One thing I wonder about is which of my 2 ports might be better located. Both have the notch not into the flowpath and some people seem to think that is vital. Funny to see so many different ways of installing the slash cut pipe nipples as well as instructions that are so blurry you can't see the notch.
I am also a big concerned backfires will kill the valves, since I backfire on purpose