Hey guys. I have a evo 8 build engine big turbo. I have small oil catch can with filter on top. I noticed that it is smoking very bad. It does not smoke when car is cold but it does smoke ( vape) when car get warm. You can clearly see a lot of vape from the filter and if I drive with closed windows all smell going inside the car and it is bad. Smells like e85 inside the car all the time. I know I can have some blow by that's why it is smoking ( it was build a little looser for high boost) but is it any way to help the situation? Compression is good, leak down test is good also, but catch can smoking like a train. Should I get bigger catch can or should I locate it to the back of the car? How you guys running catch cans on big hp evo's? I have a lot of water in the catch can even after short drive. Thanks!!

 

What can do you have? I have the STM trans mounted can paired with my STM shortblock w/a -10 block vent and 2 -6 VC fittings with zero issues.

I bet your can size is a factor if the blow by is that significant

 

I have something like this. I think thats too small for 2x 6an fittings from valve cover? I dont see smoke in warm day I can smell it only, but at night when temp drop to lets say 55-60f I can see a lot of smoke coming out of it.

 

My car doesnt have the same issue but I put my breather infront of the intake filter because I was anticipating the oil stink. I basically installed the catch can to hug the vertical intercooler pipe

 

BTW does your PCV work for idle/cruise?

 

I dont have pcv valve. It is out. I did checked yeasterday and my rear valve cover is 10an and side is 6an. I think my catch can is garbage it is too small, and I opened it and there is nothing inside, I think it should have some filter or something inside.

 

you should make pcv work (especially with your build) so that unburnt fuel does not accumulate in the crankcase and just seep out your breather while idling/cruising.
I also have mini return-catchcans but with some baffling and one similar to yours. I have the pcv working and I havent smelled oil/e85 in a long time

not a lazy set up:
https://www.evolutionm.net/forums/ev...l#post11952363

 

Thanks a lot, I learned something new. Isn't pcv valve make restriction? Now without pcv my exit is 10an but with pcv its going to be much smaller. It is smoking only on idle so it would make sense to put pcv back in the car.

 

well i'm not sure about your set up. there are 2 ports, 1 to pcv, 1 to intake...only the latter is for pressure relief. some people with lots of blowby use both to relieve pressure... guessing thats what you have. I needed both too so I made the ports bigger and made the pcv side work for vacuum (suck in moisture) and boost (full WOT blowby)... that heater valve closes the path to the breather in vaccum state so the OE pcv works.
I updated the diagram since i made the pcv side maintenance-free (drain-back also)

 

Ok so my setup i very simple. I get rid off the pcv valve on the back valve cover and I replaced it with 10an and hoes going straight to catch can. On the side valve cover breather I have 6an with hose going straight to the catch can.
On you setup is this red circle that I marked is this pcv valve? Also how about if you boost isn't boost pressure going back in this line where I draw an arrow? Thanks

 

red circle is pcv, correct. WOT blowby uses the 5/8 fat hoses. the line you marked is just what opens/closes the heater valve.
heres the WOT flow for the older diagram

 

Ok thanks a lot! Let me ask you a question. If I install some pcv or one way check valve, and on idle and cruise whenever car is on vacuum the vapor/water will be sucked to the intake manifold. It this ok for the engine? I noticed that my side went is smoking a lot not the one where oem pcv is going. The back one where oem pcv is going It is not smoking as much as side one I dont know why. I can install pcv or check valve and route it to intake manifold but car will suck a lot of water on idle to the engine.

 

its fine, thats what the original motor does, just use a genuine mitsu pcv valve. it just lets a tiny amount of air thru. it sucks dry air thru the maf, into your crankcase, to your manifold, eventually taking some crankcase wet air with it . i tested air intake without the maf and the difference is very little.... definitely better than letting oil go into my intercooler
air pressure will take the path of least resistance. your smokey vent may have a bigger port/hose. plus the crank's rotational direction might be promoting more pressure to that port

 

I highly recommend Radium catch cans. It's way better quality than everything I had. Also fitting for evo is just perfect, you can get a can on right, left or both

http://www.radiumauto.com/Catch-Can-...-8-9-P385.aspx

 

Gas ported top rings from sealed power. Gapless 2nd rings.