my FI PCV/Crank VAC system.
Staging Lane
Joined: Sep 2004
Posts: 91
Likes: 0
I have read but still do not understand. IS it possible for you to make one post with what I leave out??
1) two lines from valve covers to the turbo inlet have nothing inline. This is for pulling a vaccum when in boost
2) from PCV to a catch can then a one way valve after the can but before the vaccum source on the engine.
Is that all???
Thanks
1) two lines from valve covers to the turbo inlet have nothing inline. This is for pulling a vaccum when in boost
2) from PCV to a catch can then a one way valve after the can but before the vaccum source on the engine.
Is that all???
Thanks
Last edited by Lethal Injection; Jul 20, 2006 at 07:58 AM.
hey search is working!
mightymouse or anyone else that knows , what exacty is that brake booster breather called? some sort of mechanical vent with a rubber diaphram? also...... with the two lines running to the intake of the turbo do you have any oil draw in them? my d1sc is pushing the dipstick and i also notice oil in the line that goes to the supercharger intake. maybee a second oil catch can between those lines and the filter intake? the oil is bad in the intake streem of the turbo or centri charger right?
mightymouse or anyone else that knows , what exacty is that brake booster breather called? some sort of mechanical vent with a rubber diaphram? also...... with the two lines running to the intake of the turbo do you have any oil draw in them? my d1sc is pushing the dipstick and i also notice oil in the line that goes to the supercharger intake. maybee a second oil catch can between those lines and the filter intake? the oil is bad in the intake streem of the turbo or centri charger right?
Thread Starter
Joined: Nov 2001
Posts: 10,018
Likes: 51
From: Virginia
hey cool thread.. over a year later and this same system is venting my crankcase, giving vac to my crankcase, and keeping my very low turbo from putting oil in the exhaust. the motor has loosened up the the amount that i only can have one line running from engine to turbo intake.
yes you need to draw from a spot that does not have a lot of oil flying around.. or a seperator if you are worried about it.
yes you need to draw from a spot that does not have a lot of oil flying around.. or a seperator if you are worried about it.
Is this a correct diagram?
My question is, where does the back passenger side port run to? Or does it just sit open like you have it in the picture with the valve (which i was wondering where did you get it?)
I dont have LS6 valley cover, would my picture work? Im only concerned about my mcmaster carr vacuum block situated off the brake booster (its already splitting off to 4 ports for WG, BOV, Boost guage, and meth controller).
Thanks for all the info.
edit: is there any issues with running that front pass port directly to turbo? Doesnt oil get in there?
My question is, where does the back passenger side port run to? Or does it just sit open like you have it in the picture with the valve (which i was wondering where did you get it?)
I dont have LS6 valley cover, would my picture work? Im only concerned about my mcmaster carr vacuum block situated off the brake booster (its already splitting off to 4 ports for WG, BOV, Boost guage, and meth controller).
Thanks for all the info.
edit: is there any issues with running that front pass port directly to turbo? Doesnt oil get in there?
Last edited by JAvenger007; Sep 26, 2007 at 01:21 PM.
you mean the port on the front of the manifold or the back going to the brake booster?
I have my standard line coming off the back of the manifold going to the brake booster. Then i was going to plug the intake port on the front.
I have my standard line coming off the back of the manifold going to the brake booster. Then i was going to plug the intake port on the front.
ive got both valve covers T'd together with a check valve in each line then going to a catch can.the other port on the catch can goes to the inlet nipple on the compressor side of the turbo.done.
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Verdad Gallardo so your new pcv valve is going on the back driver side valvecover where the hard plastic 90 degree piece is with the stock pcv hose connection? does need to be drilled or is the new pcv valve a drop in fit?
thanks
thanks
Originally Posted by ZDOG
so your new pcv valve is going on the back driver side valvecover where the hard plastic 90 degree piece is with the stock pcv hose connection? does need to be drilled or is the new pcv valve a drop in fit?
thanks
thanks
no it was for mighty. he put a different pcv valve in the valcover i believe.........
so on your set up you pull no vacumn?
your check valves do what? keep boost from going to your catch can or keep oil from it or keep air from going into the valvcovers?
also if your catch can has a breather and your sucking air from the catch can with the inlet of the turbo, arent you just sucking air straight from the breather on the can?
not trying to be a pain maybee i just dont see it.
to me it looks like.... you just put a breather on the oil cap(like you have), plug the valve covers, remove lines with checkvalves, and remove the catch can its the same system you have drawn as far as vacum and air draw?
so on your set up you pull no vacumn?
your check valves do what? keep boost from going to your catch can or keep oil from it or keep air from going into the valvcovers?
also if your catch can has a breather and your sucking air from the catch can with the inlet of the turbo, arent you just sucking air straight from the breather on the can?
not trying to be a pain maybee i just dont see it.
to me it looks like.... you just put a breather on the oil cap(like you have), plug the valve covers, remove lines with checkvalves, and remove the catch can its the same system you have drawn as far as vacum and air draw?
check valves make sure air only comes out from the valve covers not back into them.it will draw a vacuum under boost.the breather on the catch can is simply to vent any pressure that builds up while under boost or if theres extra vapor that needs to vent that the breather on the pass side valve cover isnt doing enough.that breather on the catch can isnt going to pull so much air in under boost so it will pull air from the line coming from the valve covers.alot of setups i see dont vent both sides.this way it pulls a vacuum under boost from both sides.ive had no oiling problems and the catch can has always been empty.
Ok please bare with me on this. My car pukes oil out the dipstick. I have a gen 1 sbc with twin turbos. Currently I just a hose going from each valve cover to a catch can. I realy like this setup mightymouse has but still not clear what I need to do. Can someone draw a diagram for me. I want to use my brake booster as my source to pull vacum.
Thanks in advance
Thanks in advance
MM, when not in boost you are pulling a vacuum on the valve covers/crankcase from normal engine intake vacuum. At idle I have 11" of vacuum and some times under normal driving you can have up to around 20" of vacuum in your intake. Wouldn't you have the same vacuum in the crank case the way you have you driver valve cover vent hooked up to the brake booster line?
MM i think i know how your system is set up and works, I am lookig for way to set my car, although it is procharged,
You have a sealed system , valve covers vent down to the inlet side of your turbo constint vac , then under boost same thing , still pulling air (PCV) from the motor down to the turbo.
but if any boost wad to build up the one way break booster valve you installed would open and relieve that pressure,
sounds good and a safe way of doing it.
So you have no breather , its sealed , like the stock set up.
I know GM made a special oil filler cap that has a built in check valve vent that will relieve presser if the crank case built up , and this is for NA LS1 cars. But i think the cap wont open till like 2- PSi.
MM can you please draw a sketch and post it here of your PCV system, i think that would make thigs eazy to understand
thank u
You have a sealed system , valve covers vent down to the inlet side of your turbo constint vac , then under boost same thing , still pulling air (PCV) from the motor down to the turbo.
but if any boost wad to build up the one way break booster valve you installed would open and relieve that pressure,
sounds good and a safe way of doing it.
So you have no breather , its sealed , like the stock set up.
I know GM made a special oil filler cap that has a built in check valve vent that will relieve presser if the crank case built up , and this is for NA LS1 cars. But i think the cap wont open till like 2- PSi.
MM can you please draw a sketch and post it here of your PCV system, i think that would make thigs eazy to understand
thank u
Thread Starter
Joined: Nov 2001
Posts: 10,018
Likes: 51
From: Virginia
i actually built a 0psi pressure release valve out of a pep boys valvecover breather, one with a removable top. works perfectly and have since removed the brake booster valve from the valvecover and just use this one 'breather valve' as my oil cap.
i'll see about a sketch. i did post pics
i'll see about a sketch. i did post pics
Thread Starter
Joined: Nov 2001
Posts: 10,018
Likes: 51
From: Virginia
the only thing not totally clear in the pic is the idea that you have to size your hose(s) from the crankcase to the fi inlet pipe to regulate the amount of vaccum the crankcase will 'see'
you will know you have too much crankcase vacuum when you hear air squealing past the front and reear main seals
you will know you have too much crankcase vacuum when you hear air squealing past the front and reear main seals
Last edited by MIGHTYMOUSE; Dec 8, 2009 at 06:30 PM.
OK MM , i see,
but why no catch can in line down to the turbo?,
I run a catch can between both valve covers and the procharger intake hat, otherwise i think i be full of oil down there.
also i have both throttle body and PCV intake ports plugged off , why do you need to vent to the intake manifold , when you can just vent every thing down to the turbo?
are you using a LS6 valley cover?
Also i want to defitley want to add that relief valve on my valve cover like you did, i would like to mount it and use it as my oil filler cap. can u let me know what parts u used and please post a picture of it.
but why no catch can in line down to the turbo?,
I run a catch can between both valve covers and the procharger intake hat, otherwise i think i be full of oil down there.
also i have both throttle body and PCV intake ports plugged off , why do you need to vent to the intake manifold , when you can just vent every thing down to the turbo?
are you using a LS6 valley cover?
Also i want to defitley want to add that relief valve on my valve cover like you did, i would like to mount it and use it as my oil filler cap. can u let me know what parts u used and please post a picture of it.
Thread Starter
Joined: Nov 2001
Posts: 10,018
Likes: 51
From: Virginia
answer 1: no catch can between my ls6 valley cover cuz it does a pretty good job of controlling oil AND the seperator was too much of a restriction to limit my crankcase vaccum the way i wanted.
answer 2: the intake makes much more vaccum during part throttle situations than the inlet pipe ever could.. especially on a turbo car
answer 3: its a pep boys spectre valve cover breather, i put a piece of rubber inside it to make it into a valve
these are the money shots here. if somebody wants to market these i am cool with it long as i get free ones.
cut the foam that it comes with down to set the amount of positive 'cracking' pressure
answer 2: the intake makes much more vaccum during part throttle situations than the inlet pipe ever could.. especially on a turbo car
answer 3: its a pep boys spectre valve cover breather, i put a piece of rubber inside it to make it into a valve
these are the money shots here. if somebody wants to market these i am cool with it long as i get free ones.
cut the foam that it comes with down to set the amount of positive 'cracking' pressure