SPOHN'S Journal II Track Demon Reborn

wstar

I don't think putting separate breathers on the valve cover intakes is going to affect much of anything on the other side. The other side will still be drawing from the crankcase (through a can I'd guess).

I hope you don't mean you capped all of your PCV system. The engine needs to breathe or you'll build up crankcase pressure and it will cause oil seal leaks (e.g. at the front and rear of the crank).

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SPOHN

As far as the PCV system goes I have filters on the intake side. Then I will be running a oil catch can vented to atmosphere while the manifold will be capped off. These are just some progress pics. Trust me, I know what I'm doing. Lol. I might not run a OCC. just let it vent as is directly from the Check valve.

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Sh0velMan

Air doesn't blow out of the outlet though, you have to put vacuum on it to draw it out.

That's why I said you'll run lean unless you plan on installing an electric vacuum pump to evacuate the crankcase.

I've tested this on my own car and confirmed that without vacuum on the PCV outlet, no air passes through the crankcase (other than blowby).

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Kingbaby

Yea...I capped off the bridge on the crankcase, and the one on the driver side. Keep the one on the passenger side going to the back of the intake manifold.

thought?

EDIT:

I'm NA

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wstar

Well, if he were to vent both sides of the PCV system straight to atmosphere (through filters) and not use vacuum, it would *probably* work. I think the only downside there is that it's only the blowby pressure that will occasionally force a small amount of air out the breather side and/or PCV valves (whichever is least resistant). Thus pressure will be somewhat regulated and sane. But you won't really clean the ugly vapors out of the crankcase much either with no real flow or air exchange.

Running breathers on the intake side as pictured is fine, IMHO. It's really not much functional difference from the stock configuration where the intake air filters play the role of that breather (and as a bonus - sometimes there is flow reversal and/or backfire through that line - at least that won't be going into your intake). But on the other side, you should hook up vacuum through a catch can. This will actively draw negative pressure on the crankcase and keep fresh air coming in through the breathers to replace it. If you were to vent the catch can to air and cap off the vacuum, the catch can won't really do anything (you might as well be venting both sides to air as above).

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SPOHN

After discussions with Sam at GTM there is absolutely nothing wrong with putting filters on the intake side and leaving the others side completely vented to atmosphere and using no catch can at all. That's my plan. Maybe put filters on them so nothing can go in the holes.

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wstar

Yeah I guess so long as that other side still has PCV valves on them, they should only flow outwards.

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synolimit

I've never known a race track that will allow this during tech inspection. If the motor blows oil has a direct line out of the motor and onto the track and your headers. I've only known OEM setups with a catch can not vented to atmos to be legal. If the motor goes everything's contained and will run through the motor and crop dust everyone as you blow smoke out the tail pipe. At least then the oils had a chance to burn up a little. Yes throwing a rod out the block will contain no oil but that's if it happens and un-foreseeable. Yes I also know that's not the normal flow of air when hooked up but a blown motor can change the dynamics of the flow. I personally wouldn't run anything to atmos on the track. On the street I do.


Pic?



On other cars I've let it just come out if it needed to; vented to atmos, never had issues. I do think you'd run lean though "if" it were still attached to the manifold because it'd be drawing in unmetered air.

Except the MAF sensor already accounted for the air brought in through the real air filters. That's not fine as pictured because the manifold will now bring in air into the motor from two (4 total) different locations. One metered, one not. Only way it will work is a 100% capped off system letting the pcv's just open from pressure building up behind them, or OEM with a OCC. as stated though, Its not track legal to just let crank pressure blow out to atmos. Oil on the track or headers if the motor goes = burned alive.

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13 370z-

Sh0velMan

I just want to say one last time that if you put breather filters on all four PCV connections, you will have no more positive crankcase ventilation.

Your crankcase will be ventilated, of course, and any pressure build up due to blow by will be relieved, but fuel and water vapor will condense inside your crankcase every time the engine cools and nothing will forcibly remove those vapors while the engine is warming up. PCV exists for reasons other than just emissions, it keeps potentially corrosive vapors from collecting inside your crankcase.

Sam is absolutely correct that it will not hurt anything short term, but think about what is going on inside there over the course of a year or more. Water and gasoline sitting on parts that were never meant to have water and gasoline sitting on them.

I just really think it's foolish to do the "elimination" when you gain absolutely nothing by doing it and cause a vulnerability in the process. Last I'll say on it, I promise.

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synolimit

ok than what if you blocked off the rear valve location completely? and left the PCV in place? this way nothing can enter from the rear and when the car is off the PCV is in a closed postition. so nothing can enter in and when enough pressure has build up when running it will force the valve in the PCV to open and vent blow by pressure. i sucked on the valve, it takes no suction at all to open it so blow by pressure would have no issue opening the valve and venting to atmos or a OCC.

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13 370z-

Red__Zed

With FI it's probably smarter to eliminate it than to leave it. You're looking at a very different engine ecosystem with boost.

Sh0velMan

I don't see how.

Every factory FI car I've owned had it, worked fine. Difference all of those systems are draw-through rather than blow-through.

As Syno has pointed out, the valve closes so as not to allow pressure into the crankcase. Under boost, no evacuation occurs, this is normal. Off boost, the system works as previously. We're talking about 8-9 PSI at most on the stock bottom end, so the boost pressure isn't likely to destroy the PCV valve.

I can see how you'd pretty much have to run breather filters though, otherwise the inlet ends up being on the cold pipe (and thus pressurized) since we run blow-through FI on these cars. I can tell you from testing that the car will adjust the idle air bypass to adjust for what is essentially a vacuum leak if you run the PCV vacuum without having it plumbed to the intake tube.

With proper tuning, it could probably be made to work fine, so that's my suggestion:

Breather on inlet, outlet to manifold, drivability tuning to account for the more or less static rate of flow through the PCV system off boost. Static meaning the orifice is always the same size, so you can adjust for it easily. You'll get the good evacuation without the risk of boost pressure causing issues in the crankcase. Win/win.

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SPOHN

This is how I work


Subframe Dropped






OEM Bushings removed. Real PITA


New SPL Bushings in the freezer to be installed tomorrow

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SPOHN

Brief Pics of windsplitter in progress

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sixpax

Looks great SPOHN ... is the windsplitter a modified APR Universal Kit ?

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