KA24DET PCV Questions

[SpaceKADET]

I have a 2004 Frontier with a KA24DE that I have turbocharged. I have installed an Xcessive intake manifold originally meant for a 240SX and I am running a Z32 mass air flow sensor on the turbo inlet pipe.

I currently have the PCV valve on the lower passenger side of the engine venting to atmosphere and the nipple from the valve cover venting to atmosphere as well. If I remember correctly, not having the PCV hooked up to the intake manifold screws with the readings of the MAF? Do I need to find a way to plumb the PCV back into the intake manifold with a sealed can in between? Would I need an additional check valve in that instance?

Should I just run the nipple from the valve cover to a sealed can and then onwards to the turbo inlet after the MAF or can I get away with venting to atmosphere?

The build was originally venting the valve cover to atmosphere and the PCV was still plumbed into the stock intake manifold. It was originally running off an Apexi SAFC2, which wasn't the best, but it ran. Now that I'm running an S13 ECU I'm trying to get everything running properly. With the different intake manifold installed, I was wondering if I should run the PCV the same way or differently.

[kyral]

it only affects maf readings if one is connected to the intake and one is open to the atmosphere

[SpaceKADET]

So if both vent to atmosphere then it shouldn't be an issue?

[Kingtal0n]

you need a fully intact pcv system or the engine will gradually turn to shit
'
nothing should be atmospheric on an engine

[SpaceKADET]

Okay, so if it needs to be intact, PCV to sealed can to intake manifold and then valve cover to sealed can to turbo inlet after MAF?

[kyral]

you need a fully intact pcv system or the engine will gradually turn to shit
'
nothing should be atmospheric on an engine

please explain

[zombiewolf513]

Okay, so if it needs to be intact, PCV to sealed can to intake manifold and then valve cover to sealed can to turbo inlet after MAF?

Yes

please explain

Without vacuum on the crankcase, the gas pressure builds and blows out seals/rings.

[kyral]

Yes



Without vacuum on the crankcase, the gas pressure builds and blows out seals/rings.
it wouldn't blow anything out if its vented

I was reading on it, it said the vacuum helps to remove the gases and a sealed system extends oil life. so far is about all ive found for negative effects created from venting to atmosphere.
most of the reasons seemed to be pollution

[S14rebuild]

Was told a sealed, vacuumd system helps seal rings

On my sr, i never ran a pcv system, 6 years daily drove not one issue.


On my new setup im going to run a "proper" pcv and catch can setup.

[zombiewolf513]

it wouldn't blow anything out if its vented

I was reading on it, it said the vacuum helps to remove the gases and a sealed system extends oil life. so far is about all ive found for negative effects created from venting to atmosphere.
most of the reasons seemed to be pollution

i mean are you trying to argue about it? you asked a question so i gave you an answer lol. just run it vented then, its your car

[kyral]

i mean are you trying to argue about it? you asked a question so i gave you an answer lol. just run it vented then, its your car

just makin a point that venting would relieve the pressure enough that seals wouldn't leak

[JDM240z]

On my KA my PCV setup is two AN bungs on the VC and one the Block, all go to a catch can, filtered to atmosphere. No issues on a built KA with MAP and standalone.

[JDM240z]

Yes



Without vacuum on the crankcase, the gas pressure builds and blows out seals/rings.

That's not the case at all. PVCs on stock KAs are built for emissions and that's it. If you boost an old KA with a blocked or no PCV system then you blow rings, foul valve seats.

[zombiewolf513]

We're not talking about an N/A KA, now, are we?

[JDM240z]

We're not talking about an N/A KA, now, are we?

No we are not, we are talking about what a stock PCV system actually does. Which is to vent blow by to the intake for emissions. Venting to atmosphere is perfectly fine, use a one way valve though. Luckily most people don’t have to worry about emissions.

[zombiewolf513]

Maybe read the title of the thread. But if this discussion about PCVs has to be had for the 35,000th time:

https://help.summitracing.com/app/answers/detail/a_id/5233/~/what-does-the-pcv-valve-do%3F

What does it do?
The PCV valve serves a few purposes:

1)It stops excessive amounts of oil from being drawn out of the crankcase.
2)It regulates the amount of Vacuum applied to the crankcase.
2A)At low rpm, when vacuum is high, the valve closes slightly to reduce airflow.
2B)At higher rpm, when vacuum is less, the valve opens more to increase airflow.
3)It acts as a 1-way check valve for forced induction or a backfire. It won't allow the crankcase to be pressurized.


A diagram of a PCV valve working at low rpm, high rpm, and a backfire.
https://static.summitracing.com/global/images/FAQs/5233/PCV_Valve.png


How does it affect performance?
The PCV valve controls your PCV System. Follow your maintenance schedule and make sure the valve and The PCV Hoses stay clean and clear. This will extend the life of your oil and the engine itself.

The PCV system also helps the engine make a little more power. The slight vacuum in the crankcase improves the seal of the piston rings and valve stems. This keeps the compression in the chamber, where we want it. A PCV system also reduces windage and oil aeration. These cause drag on the rotating assembly and rob you of some power.



http://www.hastingsfilter.com/Literature/TSB/94-2R1.pdf


Blow-by gases and vapor should be removed at about the same rate they enter
the crankcase. Since blow-by is minimal at idle and increases during high speed
operation, the PCV valve must control the flow of vapor accordingly. The PCV
valve is designed to compensate for the engine ventilation needs at varying
engine speeds. It is operated by manifold vacuum which increases or decreases
as engine speeds change.

A neglected PCV system will soon fail to function and the result can be
expensive as well as troublesome for the car owner. If the crankcase is not
adequately ventilated, the motor oil will quickly become contaminated and heavy
sludge accumulations will begin to form. Internal parts, not protected by the
motor oil, will begin to rust and/or corrode due to the water and acids that will
become trapped within the crankcase. If the PCV system is not functioning
properly, the flow of crankcase vapor into the intake manifold will not be properly
metered.

The engine is designed to use a PCV system connected to vacuum. Running the engine without vacuum applied to the PCV effectively disables the PCV, because the spring in the valve is designed to function with vacuum. All you have to do is hook up the catch cans between the PCV and the vacuum source. To OP's point, if your vacuum source is the intake manifold, you could run the appropriate check valves between the can and manifold to prevent boost pressure from building in the catch can. Some catch cans have the necessary venting included. It's really not that difficult to understand.

https://i.imgur.com/UlrWgL5.png

[JDM240z]

Thanks for proving my point. We are not talking about the OP's stock NA KA emissions system. We are talking about how to properly vent crankcase pressure on a modded KA. If your KA is boosted, big mani, SR ECU, why on earth would you ever keep an NA PCV emissions system? You seem to be really wanting to add an emissions system to a modded motor, not something I recommend if you don't need to pass a smog test. None of these mods will pass an inspection, nor will they reduce emissions vs a stock KA. If the OP wants to vent through a one way valve ( not PCV valve) to a catch can, then to atmosphere, or if he wants to vent through a PCV valve to a catch can, back to his intake is his choice. One way is easier and cheaper than the other. Only one way is correct for a boosted KA.

[JDM240z]

[QUOTE=zombiewolf513;6403656]Maybe read the title of the thread. But if this discussion about PCVs has to be had for the 35,000th time:
It's really not that difficult to understand.

Oh and thanks for the 3rd grader Summit, NA PCV google search lesson. You are dead wrong though, here is an "Actual Authority" on why I have been doing it my way for 10yrs. OP, dont listen to this guy.

http://www.youtube.com/watch?v=TvazViNq12M&t=431s

[zombiewolf513]

You linked an hour long video about crankcase ventilation, but youre still rambling about emmissions lol. Not only that, your guy in your video describes how my '3rd grader' shit is exactly right. Did you even watch it? Or just the first 431 seconds?

Maybe you should weld your PCV ports shut.

[JDM240z]

WOW. My friend you must not have watched it at all. Or you just don’t understand it, or modified motor building for that matter. Just reading the click bait title doesn’t make you any more correct. It’s plain as day. Either way let me list the cliff notes for you.

1) 3:50 Modded engines produce more blow by than stock.
2) 6:00 Factory PCV breather system explained (Emissions)
3) 8:10 PCV valves on modified motors are bad.(Owned)
4) 11:00 Venting crankcase oil vapor in to the intake or pre turbo of a modified motor is very bad. Heard of detonation?(Owned)
5) 16:38 Keeping the factory breather system in a modified motor is bad (Owned)
6) 18:00 how to improve breather systems on a modified motor
7) 20:15 PCV on a turbo motor is again very bad. (Owned)
8) 23:30 Breather system design
9) 24:24 PCVs on a turbo motor are again very bad. (Owned)
10) 25:35 Catch can routing. Venting to atmosphere on a modified motor is good.
11) This whole thread:00 Your knowledge, attention span and reading/listening comprehension is very bad. But you do get a banana sticker for the drawing.


Yes
Without vacuum on the crankcase, the gas pressure builds and blows out seals/rings.

On a stock KA with a PCV system, perhaps. Since it’s not needed on a modified motor there is no pressure to blow rings or seals when venting to atmosphere. Like you said, weld your vents on a turbo motor and see what happens. It’s called physics.

And yes. I stated the “fact”PCV systems are for emissions, not for turbo KA’s. You seem to think they belong on a turbo motor(wrong). You seem to think venting oil vapor in to the intake or before a turbo is good(wrong). They are only good for stock cars to reduce emissions. And no I will not weld shut my crankcase venting. I vent to atmosphere like a sane person.

[zombiewolf513]

I guess I should've followed your lead and gotten a clickbait education.

The dude literally explains exactly why the PCV system on a boosted KA should reflect what my masterpiece of a PCV diagram shows. I seriously have no idea wtf you're hearing in his accent to make you think there's an argument otherwise. Half of those time stamps your labeling aren't even what he talks about. For example #3. he doesn't say its bad. He says it doesn't do anything when the engine is in boost, and needs modifications. Hence the vented check-valve in my artwork. Maybe work on your own comprehension before attempting to disparage others.

Here's some quick notes for your dumb ass:

2) 6:00 Factory PCV breather system explained (Emissions). nope venting case pressure.
3) 8:10 PCV valves on modified motors are bad.(Owned) Not bad. Don't work when in boost, hence a check valve and vent to atmposphere/or airpump req'd.
4) 11:00 Venting crankcase oil vapor in to the intake or pre turbo of a modified motor is very bad. Heard of detonation?(Owned) Heard of a catch can?
5) 16:38 Keeping the factory breather system in a modified motor is bad (Owned) Hence the modifications to the system I talked about
6) 18:00 how to improve breather systems on a modified motor see my beautiful piece of gradeschool fingerpainting
7) 20:15 PCV on a turbo motor is again very bad. (Owned) Heard of a catch can?
9) 24:24 PCVs on a turbo motor are again very bad. (Owned) Heard of a catch can?
10) 25:35 Catch can routing. Venting to atmosphere on a modified motor is good. That also has a vacuum source from the manifold, dumb fuck.

[JDM240z]

SMH... He says PCV’s on a modified motor is a terrible idea. He told you over and over again. We told you.Then he told you some more. He told you venting to the intake is even worse. And then showed you what to do, then told you again why you can’t comprehend WTF he just told you. And you tell the OP to vent to his intake with a PCV valve, and expect people to believe you when you say you will blow rings and seals if you don’t! Oh my dude thanks for the laugh. I knew I was getting trolled. Good on you.

[zombiewolf513]

Just bow out you cousin-fucking retard.

Positive Crankcase Ventilation

[JDM240z]

PCV to the intake has no place in a KA-T build. Or any other build. Don't suggest it. Your incorrect.:mepoke:

[zombiewolf513]

All you've said is 'some guy said PCV bad ditch pcv' (which he didn't even say).

You're not even make a coherent argument.

If you're so confident that PCV is bad, weld your ports shut. Lemme know how long that motor lasts. I'm sure your oil wont be fouled at all either.

Anyone reading the thread can make their own determination on their PCV, as they should anyway.

[JDM240z]

All you've said is 'some guy said PCV bad ditch pcv' (which he didn't even say).

You're not even make a coherent argument.

If you're so confident that PCV is bad, weld your ports shut. Lemme know how long that motor lasts. I'm sure your oil wont be fouled at all either.

Anyone reading the thread can make their own determination on their PCV, as they should anyway.

Knowledgeable Adults will make their own determination. Bet your NA KA :Owned:

[zombiewolf513]

oh no my reps oh noooooo

[JDM240z]

I guess I should've followed your lead and gotten a clickbait education.

The dude literally explains exactly why the PCV system on a boosted KA should reflect what my masterpiece of a PCV diagram shows. I seriously have no idea wtf you're hearing in his accent to make you think there's an argument otherwise. Half of those time stamps your labeling aren't even what he talks about. For example #3. he doesn't say its bad. He says it doesn't do anything when the engine is in boost, and needs modifications. Hence the vented check-valve in my artwork. Maybe work on your own comprehension before attempting to disparage others.

Here's some quick notes for your dumb ass:

2) 6:00 Factory PCV breather system explained (Emissions). nope venting case pressure.
3) 8:10 PCV valves on modified motors are bad.(Owned) Not bad. Don't work when in boost, hence a check valve and vent to atmposphere/or airpump req'd.
4) 11:00 Venting crankcase oil vapor in to the intake or pre turbo of a modified motor is very bad. Heard of detonation?(Owned) Heard of a catch can?
5) 16:38 Keeping the factory breather system in a modified motor is bad (Owned) Hence the modifications to the system I talked about
6) 18:00 how to improve breather systems on a modified motor see my beautiful piece of gradeschool fingerpainting
7) 20:15 PCV on a turbo motor is again very bad. (Owned) Heard of a catch can?
9) 24:24 PCVs on a turbo motor are again very bad. (Owned) Heard of a catch can?
10) 25:35 Catch can routing. Venting to atmosphere on a modified motor is good. That also has a vacuum source from the manifold, dumb fuck.

Get wrecked son, keep digging your dumb ass hole no one with a built motor would ever jump in. The fact that you think a positive crankcase valve vented to the intake on a boosted KA is acceptable shows your logic, more accurately lack there of.

[zombiewolf513]

oh no my reps oh noooooo he doesn't think I've ever built motors oh noooooooo

[Kingtal0n]

Get wrecked son, keep digging your dumb ass hole no one with a built motor would ever jump in. The fact that you think a positive crankcase valve vented to the intake on a boosted KA is acceptable shows your logic, more accurately lack there of.


PCV is the most important system on an engine.
All engines whether performance, turbo, etc come with PCV.
All race cars use some form of PCV, without it the oil would be out of control, its not a race car.

PCV is essential in every application, because:
1. low pressure pulls light chain hydrocarbons out of engine oil
2. rapid evacuation prevents oil contamination
3. low pressure enables fully intended piston ring seal function
4. low pressure reduces windage, gobular interference, and flattens rivults (too low and it can starve wrist pins for oil as a testament to its effects)
5. low pressure prevents oil leaks and seal blow-out, helps keep oil out of seals
6. low pressure keeps oil out of the engine's oil baffles and intake


If you vent an engine to atmosphere it will cut the engine's life in half or worse. It will ensure leaking seals after 20k-50,000 miles. It will ensure a smoking low compression engine is the result of typical service. It will ensure crusty piston rings and damaged cylinder walls with increased blow by due to contamination of engine oil with unfiltered air.

It will ensure that at some point the hood will become fully splattered with engine oil and dark sludge and that you will find oil everywhere, not just the intake.

This is because: Oil spray increases with crankcase pressure, and piston ring function decreases with increasing crankcase pressure.
More crankcase pressure means more blow-by and oil spray

Lower crankcase pressure is highly desirable and somewhat easily to achieve with a little effort.
Naturally this leads to desire to control and set a specific crankcase pressure range for our engine, And that becomes PCV since pcv is the only thing that can control the crankcase pressure (its the words we chose to represent taking control of the crankcase pressure).
Desired crankcase pressure would be -0.8" to 2.5"Hg of crankcase pressure in wet sump application
-0.8"Hg is -0.4PSI the minimum for most engines recommended.
2.5"Mercury or -1.22PSI is around maximum for typical wet sump application. Too much vacuum will risk damaging the oil pump and altering oil system expectations.

The air filter paper works together with PCV for the sake of longevity and cleanliness, when the engine is modified you need to re-visit the goal of each system and deviate the power(paper OEM style air filter flow rate for a modified engine) how you see fit by adjusting the PCV valve orifice and fresh air inlet orifice diameters while keeping at least one or more paper air filters on the inlet.
We measure crankcase pressure the same way as intake pressure, using 2-bar map sensor. If you can measure intake PSI then you can measure crankcase PSI. Its a 0.5v to 4.5v style sensor for every engine in the world so very easy to detect as no voltage divider is necessary. $20 Arduino micro controller has like 15x 0-5v inputs for example. HPtuners 411 OEM ecu has EGR input, 0-5v same as wideband input. You can switch between wideband and Crankcase pressure. All stand-alones can use 0-5v inputs.
No excuses not to understand and measure crankcase pressure and setup required PCV function to get maximum life from an engine and maximum oil control fantasy


Imagine not knowing how pcv works