extra breather on valve cover
after spending countless hours researching how to plumb the new pcv system on my turbo d-series civic, i've decided to go with vented black box, (will soon either get a vacuum pump or use exhaust vacuum), but that i also want to relieve more pressure in the valve cover by drilling and tapping another breather filter. are there any high-pressure areas of the valve cover that i should tap at (maybe opposite the existing breather, on the back right, so it is being vented equally on both sides?) and i know i probably want to get it as high up on the valve cover as possible to avoid getting oil spewing out of it. what size fitting do you guys think would be the best size to use? i've got a 1/4" laying around and a breather that would fit it, do i need to plumb the fitting in a special way to avoid getting oil sucked through it?
Originally Posted by wdwalker
after spending countless hours researching how to plumb the new pcv system on my turbo d-series civic, i've decided to go with vented black box, (will soon either get a vacuum pump or use exhaust vacuum), but that i also want to relieve more pressure in the valve cover by drilling and tapping another breather filter. are there any high-pressure areas of the valve cover that i should tap at (maybe opposite the existing breather, on the back right, so it is being vented equally on both sides?) and i know i probably want to get it as high up on the valve cover as possible to avoid getting oil spewing out of it. what size fitting do you guys think would be the best size to use? i've got a 1/4" laying around and a breather that would fit it, do i need to plumb the fitting in a special way to avoid getting oil sucked through it?

because i'm not going to feed oil and crap into my turbo. one of the reasons i changed it out was to remove the oil being fed into the intake. not only is this detrimental to performance, it can also cause detonation and other bad things...
Originally Posted by wdwalker
because i'm not going to feed oil and crap into my turbo. one of the reasons i changed it out was to remove the oil being fed into the intake. not only is this detrimental to performance, it can also cause detonation and other bad things...
feed it into the turbo and it will get rid of most of the oil and gunk, but it's still gonna be feeding oil vapors. hard facts. turbine blades do a lot to filter out material but its still gonna be feeding what passes through the catch can (and we all know thats not clean pure air). most racers use vacuum from the exhaust or a vacuum pump to reduce crankcase windage. you'll NEVER see them feed that stuff back into the turbo or intake manifold. of course, everything they do is done from a performance standpoint, my plan is to use more of a safety standpoint. i like my ringlands and my cam seals, and i intend to have them not be destroyed by the large amounts of blowby and high crankcase pressures of a turbocharged vehicle. i'm thinking maybe drill two holes in the front of the valve cover, connect it with some fittings/tubes and vent it to atmosphere. damn breather filters are getting expensive, i've already got 2 lol (valve cover and black box vents)
it whould be nice if someone chould clear this up, now with a oil catch can, do u have one hose go the pvc and one to the intake manifold, or do u have one go to the pvc and one to the inlet pipe in the turbo and plug the intake manifold up
turbo = nothing goes to the intake manifold. anytime you send something to the intake manifold in a turbo setup, whenever you are seeing boost air is getting forced back into the lines instead of it being sucked out. easiest way to do it on a f/i setup is to just vent it instead of sucking it out, since the only place to get vacuum on a forced induction car is either from the pre-turbo intake or from the exhaust. so i say one hose going to the pcv valve, one going to the pre-turbo intake (before the compressor). this way you'll still be venting crankcase pressure, but you'll still be sending oil and ---- back into the intake. i vent it, i put a breather on the valve cover and on the pcv PORT (took the pvc valve out). this setup works great, but whatever you do do NOT plumb ANYTHING related to the pcv system to the intake manifold or charge piping in a f/i setup. doing so = bye bye ringlands, when you're boosting you're actually making things WORSE, since you're adding positive pressure to the crankcase instead of getting it out.
you wont get the benefit of sucking out excess windage in the crankcase, but in my opinion thats the best cheap and easy option, because it vents the pressure directly out the crankcase and valve cover. i wanna go with some kind of vacuum setup in the future, cuz thats how the pros do it and you can free up some hp by getting rid of this windage, but simply venting it will relieve enough stress to keep it safe. going back to the extra breather idea though, it seems like that lil nipple on the valve cover is really small for a lot of pressure to be going out of. i'm wondering if i might have some problems with pressure buildup, possibly causing a lot of stress on the cam seals.


