021_bennett

i'm aiming for a 200whp setup and was wondering would a breather filter be adequate or will i need a breather tank setup?

Stopsign32v

iTrader: (1)

I would also like I know at what point a tank is needed.

sethm

Are you asking about a catch can setup?

Stopsign32v

iTrader: (1)

Same thing, it's just a big tank over to the passenger side firewall

sc34dc4

iTrader: (1)

A catch can setup for venting extra pressure from the crankcase is a good idea on any motor. Especially forced induction setups.

redline1219

Yeah a catch can is important, it helps relieve pressures from your crankcase. In some cases, there is dyno proven horsepower gains. Besides, who wants all that oil puking all over your motor??

Freshdot

without proper ventilation and eliminating your factory PCV setup, you will find oil creeping its way out through places it shouldn't be.

darkvader0

Besides a little K&N filter stuck on my valve cover, I run a stock PCV setup. I ran a catch-can setup for a while, but I found it more trouble than it was worth and went back to stock. I may experiment with running a vent into the exhaust...

90blackcrx

Really, the stock PCV setup, So you're boosting directly into your motor? Why would a catch can be more trouble than its worth ? Its a box that collects oil, what can go wrong ?

Freshdot

PCV systems work off of vacuum, when you are in boost you contradict its function.

darkvader0

Really, boosting directly into my motor? What are you talking about? How do you explain that?

That "box that collects oil" can fill up and need to be drained. Or it can drain back into your oil pan. I didn't want to bother with draining the can, and I didn't want that nasty gunk draining back into my main engine/turbo lubrication. I like burning excess crankcase vapors.

My engine bay is crowded. There was no easy solution to mount a catch can. When I had one, I had to relocate the battery. I didn't like that either. For me, it was more trouble that it was worth.

Now I am back to stock "boosting [20-30psi] directly into the motor" for the last 7-8 years.

ddd4114

The stock PCV valve flows more as manifold pressure increases, and when you're boosted, the crankcase pressure is much lower than your manifold pressure, so gasses flow the wrong way.

nonvtecD

+1 to that. My first D15 I boosted started weeping oil out of all the bottom end seals after 6 months of no catch can.

Mugencrxsir1

This is the most confusing conversation I've seen on here in a while... LOL

OP, no it's not necessary for 200hp.

Beneficial, yes! (I believe "Freshdot" explained it best)

90blackcrx

Yep, and boost into the crankcase.

As for not having room and cleaning a catch can out, a small catch can, can be mounted just about anywhere and it takes minutes to take off an drain, and if your motor is healthy you'll barely be draining the box up to began with.

021_bennett

Alright lads cheers i won't bother with the catch can for the moment just use a breather filter until i get money for the catch can setup...anyone have one for sale by any chance under 50 dollars just something simple?

Organization

actualy isnt the pcv valve a check valve also"one way" so when you go into boost it actually closes up letting no presure into the crankcase as long as the breather hose from the valve cover isnt hooked up to the intake pipe from the turbo it should work fine but a breather setup is still better

off boost or idle equals vacuum "pcv valve open- in boost equals presure pcv valve closed, just put a breather filter on the valve cover breather port and motor wont see extra presusre except maybe blowby preasure untill you can get a cacthcan if you want one if not it still will work without 1

darkvader0

I'm going to test myself this weekend (because you guys have me second guessing myself lol), but I'm 99.99% sure the PCV valve does the exact OPPOSITE of this. It's a one way check-valve that PREVENTS boost from going into the crankcase. I'm pretty sure I checked the Helm's diagrams where it shows manifold vacuum draws air into the valve cover, through the crankcase, through the oil seperator can and finally into the manifold through the PCV valve to be combusted. I "built" my whole system around this premise.

Anyway by no means am I saying a catch can is a bad or worthless idea, but the OP asked if it is a MUST and I say, "No." Especially in his case. In my case I decided not to use one and I am sticking with it--as long as my testing this weekend proves I understood the system correctly lol.

Tony the Tiger

The stock PCV valve does prevent boost from entering the crankcase.. The flow direction is pulling vacuum, and acts as a one-way check valve.

However, you will notice that a stock Honda PCV valve leaks under boost, so it still sends boost pressure into the crankcase. It was never intended to see positive pressure all the time. It only prevent backflow due to intake backfiring or overlap cycle.

I run a Toyota PCV valve (off a turbo car) on my Integra, and it is 100% sealed under boost. Any PCV valve that fits and came from an OEM turbo car will be 100% sealed under boost.

ddd4114

Actually, I never thought about that, so it's possible it acts as a check valve when the manifold pressure exceeds the crankcase pressure a decent amount.

However, the PCV valve should flow more with less vacuum because blow-by increases with load. I've just never seen measurements of the stock PCV system in boost.

darkvader0

Thanks for that idea. I was about to replace my PCV valve anyway. It's the original 13 year old one with 100k boosted miles on it lol.

And I think I am still going to see if I can come up with a nice way to have an exhaust scavanged PCV evacuation route. So the stock PCV valve takes care of ventilation at cruise, and the exhaust scavenging setup will possibly create crankcase vacuum under boost. Just gotta have it sourced to a location that does not pull liquid oil out.

Hybrid96EK

I can tell you this from my findings...

The stock PCV valve does leak.
My car will not eat oil unless I boost.
Once I boost, depending on the gear, its burning oil..
All the burned oil is clearly from the PCV line to the intake manifold..
Makes no difference how I route the line off the valvecover, boost burns oil..

Im still trying to figure this one out. If the PCV *IS* closed in boost, why is there oil passing through the PCV line into the intake? I have removed the intake manifold to confirm and all 4 runners had standing oil in them. Its CLEARLY from the PCV line also. Im wondering if crankcase pressure is proportional to the intake manifold pressure. I mean, does it constantly exceed that of manifold pressure and thus the PCV never closes? Blow by has to be a percentage, so as I increase combustion chamber pressure I must certainly be increasing blow by and thus raising crankcase pressure further...

Gunmetal_B20_Hatch

iTrader: (9)

I was making 300whp on a DD car with the stock PCV system. Just removed the hose on the VC and let it vent to atmosphere.