for turbo applications which form of oil catch can is better. a completely sealed one or one with a vent filter.? i am running both my PCV and my valve cover breather tube directly to a sealed catch can and my vacuum source is on top of the can. is this OK or do i need a vented catch can?

91 civic hatch, homemade turbo+ LS motor = 12 sec street car.

You have a vented rear bumper, vented air dam, and vented hood. DUDE YOU *NEED* a vented catchcan!

Turbo8u had a good post about this in the turbo section, search for it. General consensus is connecting a sealed can to an exhaust venturi to do evacuation is the best idea.

hmm ill have to check it out. ha . my rear tail conversion looks way better now . i just didnt get to post new pics yet. no more stock reverse holes. but i still got the vents.

91 civic hatch, homemade turbo+ LS motor = 12 sec street car.

I think vented is the way to go. You want to be able to release the pressure that builds in there (under the valve cover).

Kevin
The old:


The new:

im currently running both. as of this morn. i run the very right breather off valve cover to a vented and filtered can with NO vacuum line going to it.(modified water bottle) and for the PCV i run that line to a sealed catch can with a vacuum line going to it.(modified PS fluid resivoir) im thinkin this is the way to go cause that breather port to the right according to my manuals shows that air is supposed to be able to flow in to the valve cover through there too so if it was sealed off where will the fresh air come from to mix with the stuff that the PCV valve is supposed to suck out . i dunno. thats my theory. it seems to be working with no blow by to be seen in the can yet.

91 civic hatch, homemade turbo+ LS motor = 12 sec street car.