Crankcase Ventilation Mod w/Pics
#141
I have an APS TT set up on a built motor, and after a couple years, Ive been getting a little more blow by at WOT, so I decided it was time to take this on... I pretty much used rcdash's set up (thanks so much for the help!), except I routed all my hoses around the drivers side the same way the already were to keep the plumbing a little shorter... this worked out better for me with the placement of my catch can. I was able to retain vacuum very near stock at idle, so I am really happy with that outcome thus far...
And here's a little diagram I drew up to try to clear things up a little...
^^my arrow is technically backwards, but whatever, you get the idea : )
And here's a little diagram I drew up to try to clear things up a little...
^^my arrow is technically backwards, but whatever, you get the idea : )
Last edited by wtk; 05-14-2010 at 05:48 PM.
#142
Oh, and if any one is still confused at all, I wrote up a step by step with pictures that you can find here: http://www.*********.com/forums/119-...i-members.html
#143
So after running this for a couple days, I notice the engine is getting some un-metered air from the plenum. This is making me idle a bit leaner. Has anyone had to make fuel adjustments, or is it not significant enough for that?
edit: I played around with some different size hoses, I added a 1/4 hose into the one that runs to the plenum. This sort of simulated the restriction of the stock PCV, brought my A/F back down, increased plenum vacuum pressure, and it seems to be idling perfect again...
edit: I played around with some different size hoses, I added a 1/4 hose into the one that runs to the plenum. This sort of simulated the restriction of the stock PCV, brought my A/F back down, increased plenum vacuum pressure, and it seems to be idling perfect again...
Last edited by wtk; 05-15-2010 at 07:02 PM.
#145
Seriously.
Can't you just run two of those breathers? One on each valve cover, plug up the two holes and be done with it? That's what i'm planning on doing.
I'm getting blow by from the crankcase vent into my supercharger inlet. going to put a breather on and plug the SC crankcase hole.
Hoping I can do the same thing to the other side and get rid of my catch can all together.
Can't you just run two of those breathers? One on each valve cover, plug up the two holes and be done with it? That's what i'm planning on doing.
I'm getting blow by from the crankcase vent into my supercharger inlet. going to put a breather on and plug the SC crankcase hole.
Hoping I can do the same thing to the other side and get rid of my catch can all together.
#146
You can just run two breathers. You don't get any ventilation of combustion vapors (oil, fuel, water) out of the crankcase, the only downside of which is the oil getting dirty more quickly. Not a big deal if you change it out frequently anyway.
Last edited by rcdash; 05-25-2010 at 04:59 AM.
#147
So to remedy this, all you really need is 2 oil catch cans with breather filters on top. Place one on each side and run a hose from the plenum vacum port with a T fitting to both cans. It seems to me like the best catch can option out there is the ARC V2 when it comes to our cars.
#148
So to remedy this, all you really need is 2 oil catch cans with breather filters on top. Place one on each side and run a hose from the plenum vacum port with a T fitting to both cans. It seems to me like the best catch can option out there is the ARC V2 when it comes to our cars.
Most folks I think now use 1 filter right on a valve cover with the catch can only on the other side. That gives true ventilation (fresh air in one side, picks up fumes, goes out the other to the catch can, suctioned by whatever vacuum source/s you choose to use).
Last edited by rcdash; 05-25-2010 at 09:30 AM.
#149
Any *significant* amount of hose between the valve cover and filter can cause restrictive pressure build up in the crankcase. Use short 1/2" hose and that should work fine but is still not true ventilation. BB turbos are more sensitive to crankcase pressure than journal so YMMV.
Most folks I think now use 1 filter right on a valve cover with the catch can only on the other side. That gives true ventilation (fresh air in one side, picks up fumes, goes out the other to the catch can, suctioned by whatever vacuum source/s you choose to use).
Most folks I think now use 1 filter right on a valve cover with the catch can only on the other side. That gives true ventilation (fresh air in one side, picks up fumes, goes out the other to the catch can, suctioned by whatever vacuum source/s you choose to use).
#150
Not really, both heads are connected to the crankcase. you can actually blow into one cover and feel it on the other side.
Last edited by streetzlegend; 05-25-2010 at 09:49 AM.
#152
I just want to give a big hats off to this thread, I had pretty bad smoke under -ve load and a nasty whiff coming any stop. I drilled out my pcv valve and am now running the mirror of rcdash's setup (breather on drivers side, suction from plenum and intake with check valves). And no smell, no smoke, absolutely none ...
Awesomeness !!!!
Awesomeness !!!!
#153
I just want to give a big hats off to this thread, I had pretty bad smoke under -ve load and a nasty whiff coming any stop. I drilled out my pcv valve and am now running the mirror of rcdash's setup (breather on drivers side, suction from plenum and intake with check valves). And no smell, no smoke, absolutely none ...
Awesomeness !!!!
Awesomeness !!!!
Last edited by Synjn; 06-15-2010 at 02:01 PM.
#154
Ok so after reading all this I am not sure what is the best route to take.
my problem:
I'm running a vortech and have discovered oil blowing onto my sway bar out my bypass valve. Safe to assume there is oil in my intercooler. This is due to the driverside valve cover breather tube recirculating to the intake on my SC. Just after the air filter.
Passenger side: Valve cover breather tube runs to my catch can, then to the inlet on my intake plenum.
Question: Can I just plug the hole on my SC and plug the hole on my intake plenum and put a small breather on each valve cover and forget the catch can altogether? Just like the old days?
my problem:
I'm running a vortech and have discovered oil blowing onto my sway bar out my bypass valve. Safe to assume there is oil in my intercooler. This is due to the driverside valve cover breather tube recirculating to the intake on my SC. Just after the air filter.
Passenger side: Valve cover breather tube runs to my catch can, then to the inlet on my intake plenum.
Question: Can I just plug the hole on my SC and plug the hole on my intake plenum and put a small breather on each valve cover and forget the catch can altogether? Just like the old days?
Passenger side- mini K&N filter
Drivers side- PCV drilled out, -6 line to catch can, from catch can to intake piping. ZERO oil problems Just make sure you put something "mesh-like" in the can to help catch the oil and keep it from getting sucked straight through the catch can and back into the intake.
#155
Abzolutely Zexy
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From: Lithia/Tampa, Flo-Rida Bishes
Oh, and if any one is still confused at all, I wrote up a step by step with pictures that you can find here: http://www.*********.com/forums/119-...i-members.html
350z(dash)Tech.com is a blocked name site so you have to get creative with the link....like this www.350z*-tech.com (please remove *)
See if that helps the link above. Thread can be found under Power & Performance, Forced Induction, Engine, Then look for " How To: Vent Your Crank Case. Attn: F/I Members."
Last edited by shezzzhot; 06-16-2010 at 01:40 PM.
#156
<a href="http://s66.photobucket.com/albums/h244/Synjn/vacume/?action=view¤t=Picture006.jpg" target="_blank"><img src="http://i66.photobucket.com/albums/h244/Synjn/vacume/Picture006.jpg" border="0" alt="Photobucket"></a>
I recently realized that the stock hose connecting the L and R valve cover was creating a shortcut and the only thing being recirculated was the vapor under each valve cover.
Think about it: PCV (out) <----- Left cover <---- Connecting hose <----Right cover<------Breather (fresh air in).
Was never pulling from the crankcase. By cutting the connecting line, I can (under vacuum) as I illustrated pull from the left side via the plenum vacuum under low load conditions, thus good piston ring seal. Fresh air in through the right side circulating throught the bottom end.
BTW -The red indicates a 1 way check valve. Who's got good one's that actually seal?
Anyone got numbers on the vacume created at the plenum vs the intake vs the crankcase?
Most importantly having enough breather outlets for proper venting during high load/high boost conditions. The crankcase pressure is always going to overtake the vacume. Right? The pressure's got to go somewhere. So why try to pull out CC pressure when it's already moving out. (Is why I disconnected and plugged the preturbo vacuum).
I figure the moment crankcase is not boosting anymore, my plenum vacuum source will gently pull out the bad vapor.
Any input would be great.
I recently realized that the stock hose connecting the L and R valve cover was creating a shortcut and the only thing being recirculated was the vapor under each valve cover.
Think about it: PCV (out) <----- Left cover <---- Connecting hose <----Right cover<------Breather (fresh air in).
Was never pulling from the crankcase. By cutting the connecting line, I can (under vacuum) as I illustrated pull from the left side via the plenum vacuum under low load conditions, thus good piston ring seal. Fresh air in through the right side circulating throught the bottom end.
BTW -The red indicates a 1 way check valve. Who's got good one's that actually seal?
Anyone got numbers on the vacume created at the plenum vs the intake vs the crankcase?
Most importantly having enough breather outlets for proper venting during high load/high boost conditions. The crankcase pressure is always going to overtake the vacume. Right? The pressure's got to go somewhere. So why try to pull out CC pressure when it's already moving out. (Is why I disconnected and plugged the preturbo vacuum).
I figure the moment crankcase is not boosting anymore, my plenum vacuum source will gently pull out the bad vapor.
Any input would be great.
Last edited by Synjn; 07-23-2010 at 06:42 PM.
#157
Never thought about ventilating through the bottom end. So the two central nipples have one way valves that only allow gas escape? The driver's side rear vent is just an open breather? I think that would work fine also. I'm not sure that it would provide any better ventilation if the lighter vapors that you want to remove (fuel, water) are up top, but it might... If blow by is excessive it provides 2 additional outlets. Even with the center hose, I pull 4 mm Hg vacuum at idle in the catch can. You may end up sucking out more oil because of the increased vacuum from the longer circuit and from having the ventilation flow through the bottom end.
Last edited by rcdash; 07-23-2010 at 08:16 PM.
#158
Never thought about ventilating through the bottom end. So the two central nipples have one way valves that only allow gas escape? The driver's side rear vent is just an open breather? I think that would work fine also. I'm not sure that it would provide any better ventilation if the lighter vapors that you want to remove (fuel, water) are up top, but it might... If blow by is excessive it provides 2 additional outlets. Even with the center hose, I pull 4 mm Hg vacuum at idle in the catch can. You may end up sucking out more oil because of the increased vacuum from the longer circuit and from having the ventilation flow through the bottom end.
#159
http://www.summitracing.com/parts/MOR-23875/
#160
Heres what I used for my PCV return line. Moroso check valve, extremely durable.
http://www.summitracing.com/parts/MOR-23875/
http://www.summitracing.com/parts/MOR-23875/
Gotcha - makes sense. It'd be great if you could update this thread when you get an idea of how quickly oil accumulates with that set up.
Last edited by rcdash; 07-26-2010 at 04:10 AM.