HOW TO: *Properly* disconnect your PCV ...

Kirk · Post by **Kirk** » Fri Sep 26, 2008 5:53 am

Pretty much all of my emissions are removed on my car.
I have just the Moroso cut pipe welded on my downpipe (not using the Moroso valves and stuff). Running a line from that to my stock PCV valve and box. The valve cover is just vented to atmosphere with a white rag on it.
I have probably 700 miles on the car since doing this, and the only thing I have noticed is a small amount of oil on the white rag (it's not dripping out, or anything). The oil is really clean when i check it. I think it's only burned like maybe 1/4 quart this whole time.

Not saying that my way is the best way. Just saying that it does work so far, and I haven't had any major issues with doing it this way. Just have to wait and see how it does in the long run...

pa s13 · Post by **pa s13** » Fri Sep 26, 2008 4:35 pm

well i am been reading up on the moroso valve, and it seems that it only really works if you have super free flowing exhaust and no backpressure, IE no mufflers. The v8 guys say that when you are at WOT the backpressure from the exhaust closes the check valve, which isnt good because it will not let the crankcase vent. Have you had any problems with oil leaks other than your vc,

Kirk · Post by **Kirk** » Mon Sep 29, 2008 5:34 am

No leaks... The valve cover one isn't that much of a leak, it's probably more of a misting.

deuceforty · Post by **deuceforty** » Mon Sep 29, 2008 7:56 am

is the stock PCV valve on a DE is the size 3/8 npt??

im trying to buy an NPT-An conversion line and need to know the size...

240sxvaj · Post by **240sxvaj** » Mon Sep 29, 2008 1:17 pm

deuceforty wrote:is the stock PCV valve on a DE is the size 3/8 npt??

im trying to buy an NPT-An conversion line and need to know the size...

Yes, the pcv hose size is 3/8".

deuceforty · Post by **deuceforty** » Mon Sep 29, 2008 3:35 pm

not the hose, the actual fitting that goes into the breather separator

240tuned91 · Post by **240tuned91** » Sun Oct 26, 2008 6:36 pm

just did this tonight as he said to and was easily done. im not going to have any idling problems or anything right? someone told me that those pcv lines were to get sludge and mess out of the intake manifold. but i dont see how thats possible since its up at the top. nice write up orion

Liger · Post by **Liger** » Sun Oct 26, 2008 6:52 pm

Kirk - a quarter court after only 700 miles?! Wow, that's a bit of oil loss. How much oil is being sucked through the PCV setup you have?

I think the best bet is to run a hose from a barbed fitting where the PCV valve used to be, to a catch can, then a line from the catch can to the intake pipe of the turbo.

flip240 · Post by **flip240** » Mon Oct 27, 2008 12:02 am

deuceforty wrote:not the hose, the actual fitting that goes into the breather separator

they are both 3/8", the fitting is 3/8" NPT.

Kirk · Post by **Kirk** » Mon Oct 27, 2008 1:39 pm

Liger wrote:Kirk - a quarter court after only 700 miles?! Wow, that's a bit of oil loss. How much oil is being sucked through the PCV setup you have?

I'm sitting at about 2500 miles since turbo, and have probably put about 1/2 quart in the car.
It's not the end of the world. Better than having that crappy oil going back into the block, or clogging up the intake.
Oil looks very clean.

rn240sx · Post by **rn240sx** » Wed Nov 05, 2008 9:40 am

240tuned91 wrote: someone told me that those pcv lines were to get sludge and mess out of the intake manifold

yes and no....
the pcv is supposed to provide ventillation for the crankcase to help remove vapor so that the oil doesnt get contaminated. Once contamination starts, the oil will start to sludge up, and thats not pretty.
The pcv only works under partial throttle or basically during normal crusing ( 5-10 inches vacuum ) Its off/closed under idle and under boost.

sdaigle240 · Post by **sdaigle240** » Wed Nov 05, 2008 10:06 am

maby u can explain this to me bro.... if normal idle condition is 18" or whatever it is and thats what the intake manifold pulls on the pcv....then how come the intake to the turbo only pulls 1" of Hg?

i just set mine up like "chozen" or whateve his name is.... so on vac it still uses the IM. and in boost a check closes it, and durring all conditions its being pulled by the exhaust with a check. i have a feeling im going to just ghetto plug the IM connection. in the spring the mani can come off and properly be taken care of. im racing the snow here.

flip240 · Post by **flip240** » Wed Nov 05, 2008 6:09 pm

^ I did it the same way using a simlar setup to chozen's, if i were you though, I would keep the 4-port PCV setup, just route the PCV to a filter and add a 'T' so one end goes back to the 4-ports on the IM and the other goes to the turbo inlet pipe so blowby can vent when the PCV is closed and under boost conditions.

http://img.photobucket.com/albums/v379/ ... edpcv2.jpg

I talked to a DSM buddy and he told me when they modify their PCVs, they don't dump their VC's to air, but back to the intake tube like I illustrated. Even though the other Honda thread says one end should see fresh air, it doesn't make sense to me why I should be letting fresh air contaminate my oil.

Walperstyle · Post by **Walperstyle** » Thu Nov 06, 2008 12:28 am

bookmarked this thread

I cant learn as fast as I work . I need to take more time reading before doing. Good info guys, i'll come back here when I start to build up.

nelson240sx · Post by **nelson240sx** » Thu Nov 06, 2008 9:33 pm

Should get rid of any positive pressure. I plan on using 1/2" line so it can have the least amount restriction through the system. Vacuum on the system will increase when your in boost and need it most.

EstoMax · Post by **EstoMax** » Thu Nov 06, 2008 10:34 pm

nelson some of us don't want to have crank case air going back into our intake, thats what the moroso valve setup is for!

cheers
Marko

nelson240sx · Post by **nelson240sx** » Fri Nov 07, 2008 4:49 am

Since its metered air i want it back into my intake but, i have seem a lot of map (honda's) cars run the line from the oil catch can onto their down pipe to create vacuum.

sdaigle240 · Post by **sdaigle240** » Fri Nov 07, 2008 6:33 am

thats how im doing it..... (i think this was how "chozen" did it)

and screw that moroso setup.... i grabbed a peice of pipe, slash cut it and a check valve off a booster. done, and it was $0 instead of $60. either way though u still gotta buy a few feet of this hose from napa thats rated for exhaust temperatures, $9/ft.

Daily Driven 240 · Post by **Daily Driven 240** » Sat Nov 22, 2008 11:57 am

I was taking the emissions off of my s13 intake manifold last night and started thinking about how i was going to run my PCV system so i dont get any oil in my intake manifold, in the intake ports of the head and on the intake valves.

Here's a diagram of how im thinking of running it.

I do beleive that this way keeps it functioning like it should and how it was ment to and it will separate the oil from the fumes beeing burnt, wich is what i want. Also having the valve cover breather fitting routed to the turbo intake behind the maf alows the air to get metered and will not cause lean afr's on idle like a filter on the breather fitting setup would.

This is my idea of how i could run it but i may have overlooked something and maybe this can't work so if anyone has any comments or tips please do so it can help everyone out.

thanks.

Umai Kakudo · Post by **Umai Kakudo** » Mon Dec 01, 2008 6:52 pm

Here is an excellent paper on breather systems, their function and design.

http://www.106rallye.co.uk/members/dyno ... ystems.pdf

It even has maths for the sizing of properly sized systems based on maximum flow rates at WOT.

Hopefully this will help answer some questions.

duncan351 · Post by **duncan351** » Mon Dec 01, 2008 9:21 pm

nelson240sx wrote:

This is how I have my PCV routed except my catch cam has an additonal ported weled to it & the catch can was cut open to add internal baffles.) Works great and my turbo is still always clean. The turbo never sucks in oil even at high boost.

Liger · Post by **Liger** » Mon Dec 01, 2008 11:42 pm

How is putting a vacuum on both ends of the motor going to pull out vapors? It'll remain stagnant and not do nearly as much if you were to put a filter on your valve cover breather. This will allow fresh, filtered air to replace the contaminated vapors that are to be evacuated via the PCV. You will have much greater removal of harmful vapors this way vs having both ports under vacuum.

Just look at how Nissan and any other car maker does their PCV system. All that needs to be done in our case is re-route the stock PCV system to the pre-turbo piping so that under boost there will always be vacuum on the crankcase, not just partial throttle.

flip240 · Post by **flip240** » Tue Dec 02, 2008 1:00 am

the VC is connected to the intake tube, and in a stock setup, will see vacuum under all conditions except idle.. how is that the same as putting a breather on the VC? if that was the case, why not put the VC intake at the filter box?

i've been looking into how subaru's and evo's do it, and both have similar setup where a combination of turbo intake pipe and intake manifold vacuum is used to evacuate the crankcase. i even talked to a dsm buddy who verified that none of them have stuck a filter on their VC... that's how mustangs and what-whos do it, not turbo cars.

Daily Driven 240 · Post by **Daily Driven 240** » Tue Dec 02, 2008 8:20 am

the reason why i wouldnt put a filter on the breather fitting on the valve cover is because the system is set up to burn off the harmfull vapours in the crankcase, the valve cover fitting is used to pull fresh air back into the crankcase to replace the vapours, well that fresh air needs to be metered by the maf so that you dont run slightly lean on idle. thats my understanding from seeing how its done from the factory through the fsm.

ppctx · Post by **ppctx** » Tue Dec 02, 2008 9:42 am

Daily Driven 240 wrote:the reason why i wouldnt put a filter on the breather fitting on the valve cover is because the system is set up to burn off the harmfull vapours in the crankcase, the valve cover fitting is used to pull fresh air back into the crankcase to replace the vapours, well that fresh air needs to be metered by the maf so that you dont run slightly lean on idle. thats my understanding from seeing how its done from the factory through the fsm.

That’s my thoughts on the subject... but to each their own.

There are many means and methods to dealing with crank case ventilation with varying levels of effectiveness and ease of implementations. Pick your poison and be happy.

Now can this thread please die. It’s the same information and thoughts rehashed again and again, to the end of being pointless.

flip240 · Post by **flip240** » Sun Dec 28, 2008 10:48 am

Concerning the issue that crankcase vapors can only vent through the front cover, I was helping my friend diagnose his BMW, and came across this diagram for the BMW E36 M3 engine.

The tube obviously isn't ideal diameter for venting blowby, but I guess if it works for BMW? lol. (it's listed as a vent hose).

Originating link
http://www.realoem.com/bmw/showparts.do ... g=11&fg=15

EstoMax · Post by **EstoMax** » Thu Jan 22, 2009 7:41 pm

annnd to bring it back from the dead and add some info for future reference. I am experimenting with a slash cut tube in the downpipe and having it at a 45 degree angle, flush with the DP, does not work.

see this thread for info on that:
viewtopic.php?p=311679#311679

Marko

480sx · Post by **480sx** » Fri Jan 23, 2009 5:57 pm

You didnt setup the slash cut right to achieve a venturi effect bro. I dont have the link anymore to the picture on how to do it right but, the slash itself is supposed to protrude into the exhaust stream.

Like this

--------| |----------
~~~~~~~|/~~~~~~~~~~~~~~~>>>> Exhaust flow
-------------------

torch'd · Post by **torch'd** » Fri Jan 23, 2009 9:40 pm

8-bit wrote:I basically took off all the rubber and there was a nearly 1 inch nipple on each hole. I put a lot of JB weld in em. I really pray (to the dirt) that they will hold up. So far 12psi for several months, and 30psi on occasion when I have pressure checked my system.

EDIT: make sure you do the RTV if you're gonna do this guys! Air loves to leak around those threads!

my thopughts exactly lol.

schmauster920 · Post by **schmauster920** » Sat Jan 24, 2009 10:15 am

Fuel pwns RTV, i would seal those threads with JB kwik... for those of you that dont know its a liquidy form of jb weld that comes in 2 tubes like epoxy.. very badass for sealing threads and things that you dont plan on removing

www.ka-t.org

HOW TO: Properly disconnect your PCV ...