i have a new style ls6 valley cover with the pcv built in. i have fabricated aluminum valve covers. i was wondering if its necessary to run a -10an line off of each cover to a catch can. or do you think ls6 valve cover will vent enough air to eliminate blowby? thanks.
true. so i think i am going to run -10an off of each cover since you cant have too much ventilation. i was just going to run the vent off of the ls6 valley cover to a catch can also and not vent anything back into the system. do i really need to vent the ls6 cover back into the system? or can it just be atmospherically vented like the valve covers? my last setup didnt involve any venting back into the system at all.
yeah thats what my plan was. im on another thread right now where this guy said the pcv system needs vacuum to properly vent all of the **** out of the engine but im sure venting it like you stated would work perfectly.
I would like to add a PCV to draw fresh air through the crankcase.
But it would need an exceptionally good oil/air separation system to ensure no oil ever got into the intake.
I'm not convinced I can achieve that reliably, so I'll just keep it simple and vent everything to atmosphere via a can.
does the pcv draw vacuum at any point in time? i thought that the pcv and valve covers all had positive pressure and didnt pull vacuum. how would the pcv draw fresh air through the crankcase then?
I guess it depends how you configure it.
If you add suitable valves so it can create a vacuum in the crankcase then yes. It does add complication to do that though.
Or you can just use a single non-return valve at the intake and allow it to pull air through the crankcase at all times other than boost.
Seems the preferred method of doing this is a line/non-return on one valve cover and adequate venting on the other and/or the valley.
So under vacuum air always gets pulled through the engine, on boost when the valve closes, the crankcase just breathes through the open vents.
Obviously for any setup where air gets drawn into the engine from the crankcase, you will need efficient oil/air separation so the intake doesnt suck oil into the engine.
ok got it thanks. you made it alot easier to understand. hey 1972 nova, i checked your thread out and i was wondering why you didnt use the valve covers you had in the beginning like mine? just curious
wouldnt clear my upswept headers. and just seemed like they would leak, the nasty ones i have on mine are well worth the money. I went through a set of the gmpp cast ones as well and they were junk.
But keep in mind Im running some allpro heads and the have a raised deck to clear valvetrain so the bolt pedestals did not bottom out to torque them. Went through a little headache figuring that one out but have had not a single problem since using the nasty ones.
2014 LSX True Street King @ Indy World Street Finals