Catch can options.

[e30gangsta]

Figured I'd make a quick thread discussing currently available catch can options for our cars. One of the nicer ones I've been able to find is the TF one.

https://www.tf-works.com/tf-s13-s14-oil-catch-can-V1/

Anyone else know of any other s chassis specific catch cans options besides the standard over the ras gktech ones?

[Kingtal0n]

no healthy engine should ever use a catch can

its for broken engines with broken pistons

[e30gangsta]

no healthy engine should ever use a catch can

its for broken engines with broken pistons

You're out of your mind.

[shinhed]

I'm partial to the Mishimoto baffled catch can because of the textured black, anodized finish.

https://www.mishimoto.com/mishimoto-baffled-oil-catch-can.html

Mad my own bracket though.

https://i.ibb.co/t2xxRGj/IMG-20191222-131818.jpg (https://ibb.co/t2xxRGj)

[Kingtal0n]

You're out of your mind.

No you've just been copying other people

People just copy other people without understanding what they are doing.

You ever seen an engine from ANY factory come with a catch can?

No and you never will. All Engineers know better, it is obvious to them.

Companies will sell anything that people will buy. You can find all kinds of useless garbage for sale on the internet. Just because they make something doesn't mean it has any useful purpose.
A catch can has a place: It temporarily masks the symptoms of a leaking bottom end, so the owner can drive the car while waiting to fix the engine.
Nobody should have so much oil flowing out of their engine that it requires such an external device, can you see now that the additional sight is unwanted, because now it looks like there is a problem with the engine blowing oil.
In other words, when I see a catch can, I assume the engine is bad or broken.
Sometimes people install small 'oil separators' in some places because they fear the oil may reach the intake manifold.
I am not against small devices however you can often achieve the same affect with a slightly longer hose as the hose itself will act as a deposition surface for oil molecules between the crankcase and intake manifold, thus the hose can simply be thrown away and replaced when it becomes full of deposits and it adds very little additional volume to the crankcase and it's pcv system, which is important when you desire a strong vacuum signal response inside the crankcase, it's volume must be minimal to achieve maximum affect. Or effect, which ever

I'm not saying that you shouldn't control your oil system guys. PCV is an oil control system and absolutely necessary. PCV is the most important system on the engine and tied with the oil pump function.
What I AM saying is that connecting a large, stagnant reservoir to the crankcase is absolutely unnecessary, unwanted, and incorrectly implemented most of the time. Even if it is warranted, it is very easy to install incorrectly. If the can does not heat to the boiling point of water, for example, or near that (say 190*F or so) It will obviously begin to collect water since water is a product of combustion and present in blowby gasses, as well as a normal constituent of normal outside air which enters the crankcase when the engine is *OFF*. Try to imagine adding a small container to an oven which is connected to the outside air, and routinely warms and cools each day, and is also injected with water molecules when it is warmed. Those hot gaseous water molecules must cool down and collect to form water. They will seek cold areas to do this. If the catch can is not hot enough (180-190*F+) the water will simply use it as a condensation surface each day as water is injected via blowby gas which all engines produce some of. &c.... check the links I go over this and more below
Additional volume will work against the pcv action, it will help create oil leaks, it will reduce the effectiveness of pcv. And when installed incorrectly, at the wrong height and wrong temperature, it will lead to oil contamination and reduced engine life.

[Thursday7]

No you've just been brainwashed by all the other sheep.

People just copy other people without understanding what they are doing.

You ever seen an engine from ANY factory come with a catch can?

No and you never will.

Companies will sell anything that people will buy. You can find all kinds of useless garbage for sale on the internet. Just because they make something doesn't mean it has any useful purpose. It just means the sheep are buying it.

I'm not saying that you shouldn't control your oil system. PCV is an oil control system and absolutely necessary.
What I AM saying is that connecting a large, stagnant reservoir to the crankcase is absolutely doing it wrong.

I consider it pretty necessary when I have my ring gaps opened up significantly. Does it piss oil out of the valve cover? No, but over a few events it will have a little buildup gathered.

[e30gangsta]

No you've just been brainwashed by all the other sheep.

People just copy other people without understanding what they are doing.

You ever seen an engine from ANY factory come with a catch can?

No and you never will. All Engineers know better, it is obvious to them.

Companies will sell anything that people will buy. You can find all kinds of useless garbage for sale on the internet. Just because they make something doesn't mean it has any useful purpose. It just means the sheep are buying it.

I'm not saying that you shouldn't control your oil system. PCV is an oil control system and absolutely necessary. PCV is the most important system on the engine and tied with the oil pump.
What I AM saying is that connecting a large, stagnant reservoir to the crankcase is absolutely unnecessary, unwanted, and incorrectly implemented most of the time.
Additional volume will work against the pcv action, it will help create oil leaks, it will reduce the effectiveness of pcv. And when installed incorrectly, at the wrong height and wrong temperature, it will lead to oil contamination and reduced engine life.

Companies are also not making 3x the amount of power on the original engine from 20+ years ago.

No one asked you about pcv effectiveness, how they work, or oil contamination.

I simply asked for catch can recommendations because I would like to run one on my setup. Because as we all know sr's could benefit from modifications to the crank case ventilation system.

[PoorMans180SX]

No you've just been brainwashed by all the other sheep.

People just copy other people without understanding what they are doing.

You ever seen an engine from ANY factory come with a catch can?

No and you never will. All Engineers know better, it is obvious to them.

Companies will sell anything that people will buy. You can find all kinds of useless garbage for sale on the internet. Just because they make something doesn't mean it has any useful purpose. It just means the sheep are buying it.

I'm not saying that you shouldn't control your oil system. PCV is an oil control system and absolutely necessary. PCV is the most important system on the engine and tied with the oil pump.
What I AM saying is that connecting a large, stagnant reservoir to the crankcase is absolutely unnecessary, unwanted, and incorrectly implemented most of the time.
Additional volume will work against the pcv action, it will help create oil leaks, it will reduce the effectiveness of pcv. And when installed incorrectly, at the wrong height and wrong temperature, it will lead to oil contamination and reduced engine life.

You have got to be trolling. Tell that to all the direct injected cars with carbon buildup issues. Such engineering, much wow.

Oil in your intake manifold is never helpful to your engine, ever. I would agree than an open-atmosphere catch can is definitely not the best solution, but that doesn't mean you don't want to figure out how to keep that oil mist out of your intake.

Companies are also not making 3x the amount of power on the original engine from 20+ years ago.



100%!

[S14rebuild]

If/when i goto to clutch fan, i like the gktech one...(mounts ontop of the fan shroud)

[driftyour40]

https://dsportmag.com/the-tech/quick-tech-the-benefits-of-lowering-crankcase-pressure-part-1/

https://www.truefocusfab.com/product-page/nissan240sx-s14-tucked-catch-can-1

[Kingtal0n]

You have got to be trolling. Tell that to all the direct injected cars with carbon buildup issues. Such engineering, much wow.

Oil in your intake manifold is never helpful to your engine, ever. I would agree than an open-atmosphere catch can is definitely not the best solution, but that doesn't mean you don't want to figure out how to keep that oil mist out of your intake.



100%!

First of all, the carbon buildup on the valves issue has been shown to have nothing to do with the pcv system or oil aspiration via intake manifold.

Second of all, there is only a very narrow year range for DI performance engines that matter, which have the critical 'flaw' of not incorporating port injection. iirc its from say 08 to 2012. After roughly 2012 ALL performance engines use port injection on top of their DI injection to solve the valve washing issue so it never happens again.

Finally, there is no way a healthy engine can supply oil to the intake manifold through a proper baffle system. If you find oil there, then the engine was built or designed wrong, or the pcv is setup wrong, with no vacuum. Everytime the engine is in boost, And also during cruise, ALL the time: there must be a healthy vacuum in the crankcase of 1 to 3" Hg or the pressure will cause oil to invade seals. Actually oil will still gradually pass oil seals as the seals age and oil works it's way into everything, especially synthetic because of it's size and uniformity. So having a vacuum pcv crankcase is what allows engines to achieve 200,000 miles and 15 to 25 years of service with very little oil bypassing until finally old age.
If a brand new engine is run without this pcv vacuum that will severely cripple the mileage and age-ability of all the engine's oil seals. You will find oil leaving every orifice and pushing into every seal, one by one they will leak especially during times of stress "events" for example where the engine is run hard repeatedly without a reasonable crankcase vacuum, eliciting the response of adding a catch-device when in reality what really needs to be done is a vacuum needs to be applied to the crankcase somehow to keep the oil inside it and also protect the oil seals.
Thus: The catch can "answer" implemented with an atmospheric vented setup knee jerk response is actually facilitating the destruction and degradation of all the engine's oil seals, and helping to push oil into all orifices and channels as it searches for an exit. If you've ever seen what a broken piston does to the flow of oil leaving the valve cover baffle during boost and spraying all over the car you will understand that the pressure inside the crankcase is absolutely necessary to monitor and control in order to prevent oil from leaving an engine.

in other words, a crankcase pressure being over atmospheric will also contribute to pushing oil from the crankcase, and all vented setups will experience some pressure
With the correct pressure drop inside the crankcase, and a healthy bottom end no engine should push oil. Even the force of oil being slung away from the rotating parts should be accounted for somehow, with baffles, shields, windage trays, the factory usually provides decent versions but if it became an issue you are still responsible for modifying and fixing that issue. That is the purpose of those parts and they must be present for the application.
Protected by both pressure and physical force, no oil seals or oil orifices can flow/eject any oil content, nothing can blow out of the motor.

https://www.corvetteforum.com/forums/c6-forced-induction-nitrous/4427015-crank-case-pressure.html#post1601908393

https://www.corvetteforum.com/forums/c7-general-discussion/4394112-pissed-at-what-i-found.html#post1601381818

https://www.corvetteforum.com/forums/c7-general-discussion/4394112-pissed-at-what-i-found.html#post1601387336

https://www.corvetteforum.com/forums/c7-general-discussion/4394112-pissed-at-what-i-found.html#post1601389104
Holy crap, Ive been saying this for years, over and over again.
Literally no one is thinking this coking problem all the way through.
The engines that have coking problems are all DOHC engines.
DOHC engines have valve stems that are nearly submerged in oil, for several reasons, including head design and the fact that cams require pressure oil feed.

https://www.corvetteforum.com/forums/c6-corvette-zr1-and-z06/4381801-1000-rwhp-guys.html#post1601172559

https://www.corvetteforum.com/forums/c6-forced-induction-nitrous/4254669-catch-can-options.html#post1599127968
http://www.nsxprime.com/forum/showthread.php/154972-Oil-catch-can?p=1909408&viewfull=1#post1909408
https://www.corvetteforum.com/forums/c7-general-discussion/4114446-has-anyone-actually-been-denied-warranty-because-of-a-catch-can.html#post1596805105
https://www.evolutionm.net/forums/evo-general/754223-oil-catch-can-setup.html#post11871298

https://forums.nasioc.com/forums/showpost.php?p=46013725&postcount=99

[S14rebuild]

Ive always just ran hoses from my vc to a catch can... never had a pcv. Now im setting it up properly...

[Kingtal0n]

The correct way for high performance engines is to measure crankcase pressure using a 2-bar map sensor

here is an example at 800rwhp
https://www.corvetteforum.com/forums/c6-forced-induction-nitrous/4427015-crank-case-pressure.html#post1601922844

https://www.youtube.com/watch?v=D7HALpFvMVg
Notice that even with a vented setup the engine experiences 2psi of crankcase pressure in boost

you CAN'T just run a vent. That is archaic method (1970's)

Imagine you hook up an air compressor to your crankcase and set it to 2psi and walk away... how long until you start to see an oil drip forming at all the seals?

step1. measure crankcase pressure with a data logger
step2. adjust orifice diameters and connect the pcv in a factory orientation until you achieve desired crankcase pressure drop of 1 to 3" Hg of vacuum
step3. profit

[PoorMans180SX]

First of all, the carbon buildup on the valves issue has been shown to have nothing to do with the pcv system or oil aspiration via intake manifold.

Second of all, there is only a very narrow year range for DI performance engines that matter, which have the critical 'flaw' of not incorporating port injection. iirc its from say 08 to 2012. After roughly 2012 ALL performance engines use port injection on top of their DI injection to solve the valve washing issue so it never happens again.

Finally, there is no way a healthy engine can supply oil to the intake manifold through a proper baffle system. If you find oil there, then the engine was built or designed wrong, or the pcv is setup wrong, with no vacuum. Everytime the engine is in boost, And also during cruise, ALL the time: there must be a healthy vacuum in the crankcase of 1 to 3" Hg or the pressure will cause oil to invade seals. Actually oil will still gradually pass oil seals as the seals age and oil works it's way into everything, especially synthetic because of it's size and uniformity. So having a vacuum pcv crankcase is what allows engines to achieve 200,000 miles and 15 to 25 years of service with very little oil bypassing until finally old age.
If a brand new engine is run without this pcv vacuum that will severely cripple the mileage and age-ability of all the engine's oil seals. You will find oil leaving every orifice and pushing into every seal, one by one they will leak especially during times of stress "events" for example where the engine is run hard repeatedly without a reasonable crankcase vacuum, eliciting the response of adding a catch-device when in reality what really needs to be done is a vacuum needs to be applied to the crankcase somehow to keep the oil inside it and also protect the oil seals.
Thus: The catch can "answer" implemented with an atmospheric vented setup knee jerk response is actually facilitating the destruction and degradation of all the engine's oil seals, and helping to push oil into all orifices and channels as it searches for an exit. If you've ever seen what a broken piston does to the flow of oil leaving the valve cover baffle during boost and spraying all over the car you will understand that the pressure inside the crankcase is absolutely necessary to monitor and control in order to prevent oil from leaving an engine.

in other words, a crankcase pressure being over atmospheric will also contribute to pushing oil from the crankcase, and all vented setups will experience some pressure
With the correct pressure drop inside the crankcase, and a healthy bottom end no engine should push oil. Even the force of oil being slung away from the rotating parts should be accounted for somehow, with baffles, shields, windage trays, the factory usually provides decent versions but if it became an issue you are still responsible for modifying and fixing that issue. That is the purpose of those parts and they must be present for the application.
Protected by both pressure and physical force, no oil seals or oil orifices can flow/eject any oil content, nothing can blow out of the motor.


(sarcasm)Oh is that why every engines intake manifold is coated internally with oil film?(/sarcasm)

GTFO here dude. Oil vaporizes and becomes a mist that will absolutely flow through baffles and a pcv valve.

Also LOL at every DOHC head being full of oil. Maybe on an RB or the exhaust cams on a VG30DETT, but most engines have adequate head drains, and on an SR20 it's a giant front timing chain hole. No way that oil fills the head above the valve stems.

You assume that the people who design engines both really care about oil consumption, and never make mistakes. They care much more about meeting emissions, and the myriad of engines with inherent design flaws disproves the latter. Do you know why the latest API service specifications for oil only allows them to contain 800-900 PPM zinc? Because zinc poisons catalytic converters and it's *gasp* consumed by the engine. I mean fuck, EJ25's are known to consume tons of oil in their bone stock form, and if you've ever taken one apart, you can see the thick, black film in the intake manfold from the PCV system. Install a proper catch can system and it pretty much goes away. Shocking!

There's plenty of correct information in your posts, but it's also full of assumption. Not every engine has an adequate baffling system. Just because your favorite OHV engine doesn't have issues, doesn't mean no engine needs a catch can or air oil separator.

Again, I believe a properly integrated fresh air feed and PCV system is the superior way to do things. I also think that draining the catch cans to the crankcase is harmless and convenient.

[Kingtal0n]

Again, I believe a properly integrated fresh air feed and PCV system is the superior way to do things. I also think that draining the catch cans to the crankcase is harmless and convenient.

Integrated fresh what...? What does even mean

Superior way to do "what" things?

Be specific. I am very specific. The factory is very specific.

Specificity:
PCV implies a pressure below atmospheric.
Thus, there must be a vacuum inside the crankcase or it isn't pcv.

How much vacuum? Specifically: 1 to 3" of Hg of vacuum

It's as simple as that. Meet the criterion, and have PCV. Or not.

You sound like somebody who has never measured their crankcase pressure.
All advanced racing and high power engines 1000 2000 3000hp require crankcase pressure monitoring to determine engine health statistic. Or it is a novice installation.

The crankcase pressure must be kept in wet sump applications between 1 to 3" of Hg. That is wet sump PCV.
The air must always be filtered as high quality as possible (obviously). Every engine, every mechanical device, in every application around the world requires the cleanest possible air, this is a very obvious engineering and mechanical ideal to keep the engine clean inside. This is the only way to achieve high mileage.

Get it: Clean as possible air (superior filtration) + PCV (1 to 3" of Hg inside crankcase at all times) = high mileage capable, factory engine longevity. Daily drive-able

In this configuration, there is no oil aspiration or oil inside the intake manifold. How is that even possible? The turbocharger compressor is ten miles from the intake manifold. The oil would literally have to pass through miles of plumbing and the intercooler to reach the intake manifold, it means the engine is bad, the intercooler needs to be removed and washed out, the pipes all need to be cleaned out, the engine needs to be fixed at that point. The intercooler must remain OIL-FREE thus a healthy engine cannot send any oil to the intake manifold if the oil cannot reach the intercooler. This is the only side of the system under any form of duress during power output. The manifold suction you seem to be referencing and pcv valve config is for IDLE/CRUISE Only which is the tamest/simplest/minimal PCV flow and has nothing to do with the bottom end or engine health.

You are confused about which side of the pcv system is "working". Like so many others you fail to see how the air filter pressure drop influences the oil flow from an engine; If you remove the engine air filter then oil will gradually push from an engine due to the excess crankcase pressure. Only the air filter can provide the suction necessary to drive adequate PCV action at wide open throttle, otherwise there must be a vacuum pump or other source.

[PoorMans180SX]

Have you seriously never pulled the intake manifold off an engine and seen and felt the oil varnish in it?

Those 1000-3000hp engines you speak of are dry sump, so no shit they have to monitor crankcase pressure. They usually pull 14in of vacuum btw. They monitor it and tune it because they can pull the bearings dry if they want depending on how the dry sump is geared. Damn, it?s not that hard to understand when you know the context.

I?ve seen data logs of crankcase pressure on my old shop?s wetsump 1100whp 4G63 with only atmosphere crankcase ventilation. 2-3psi. Wooptie fuckin do. In that application it?s a drag car, it sees that for maybe 10 seconds at a time. It has no air filter and never sees the conditions a PCV valve works in anyway.

If it?s connected to the intake manifold (how most engines are configured), the PCV valve is closed under boost mate. It also may or may not be connected to the air intake of the turbocharger (which would be a pretty poor way to do it btw). On an SR20 it definitely is not. That?s because there is vacuum in the intake manifold at cruising, where the pcv is doing most of it?s work. You don?t need a pcv when connected to the intake of the turbocharger because there?s no way it sees positive pressure there.

The clean air feed I?m talking about is when cruising, where the air is pulled through the air filter, down into the crankcase, out the pcv valve and into the intake manifold. That is ?positive crankcase ventilation?. Under boost in this configuration, the PCV valve is closed, which is where your turbo intake comes in, helping to evacuate the crankcase when the PCV valve is shut. Your turbo intake becomes the only available source of negative pressure (though very little if you have a high flowing air filter).

I really don?t understand how you?re missing all of my points. This isn?t hard stuff to understand, you?re just refusing to acknowledge how these systems are setup or their flaws. Do you know VW TDI engines have a habit of running away because they pool so much oil in the intercooler? Where could this possibly be coming from on a healthy engine?!?!?!. The CCV system on that engine is a hose with a spring loaded flow regulator routed from the valvecover to the turbo intake. But but but but it was engineered that way, it shouldn’t do that right? Well it does, because no baffling system is perfect.

[Kingtal0n]

Have you seriously never pulled the intake manifold off an engine and seen and felt the oil varnish in it? ....

....
If it?s connected to the intake manifold (how most engines are configured), the PCV valve is closed under boost mate.

If the pcv valve is shut during BOOST mate, then HOW can oil possible get into the intake manifold from there during boost? Can you not see that its impossible for oil to take that route... there is no way to oil down an intake during boost because the pcv valve IS shut.

So where do you think the oil is coming from? I will discuss at length below



It also may or may not be connected to the air intake of the turbocharger (which would be a pretty poor way to do it btw). On an SR20 it definitely is not.

All sr20det engines and ALL turbocharged engines from ALL factories from ALL manufacturers ARE DEFINITELY connected this way, that is Air Intake Pipe of turbocharger -> Crankcase.

ALL of them. So what are you trying to say? Have you never seen a stock turbo engine before? This must be a typo, I do not think you mean what you say



That?s because there is vacuum in the intake manifold at cruising, where the pcv is doing most of it?s work. You don?t need a pcv when connected to the intake of the turbocharger because there?s no way it sees positive pressure there.

Sorry, "where the pcv is doing most of it's work" you have it backwards. During idle/cruise there is very little blow by, so by definition the pcv is doing the LEAST work. During BOOST is when blow-by is maximum, therefore pcv will be doing the MOST work during BOOST when the system is configured properly.



The clean air feed I?m talking about is when cruising, where the air is pulled through the air filter, down into the crankcase, out the pcv valve and into the intake manifold. That is ?positive crankcase ventilation?

That is HALF of the crankcase ventilation system. And it only counts as PCV if the pressure is below atmospheric between 0.5 to 1.5psi negative pressure. It is possible to have a massive flow of crankcase air without any negative pressure because PRESSURE and FLOW are two different things. This is where majority of people get lost. If you increase the orifice diameter and air filter flow rate you also increase PCV *FLOW RATE* to the intake manifold while simultaneously INCREASING the crankcase pressure (decreasing the effect of PCV), BOTH of which will INCREASE OIL ASPIRATION!! In other words, the two are inversely proportional at this end of the system: Increasing flow rate will increase crankcase pressure!
That is the NEGLIGIBLE portion of the pcv system. This is what you are confused about and I'm trying to fix it for you.
The intake manifold suction is MINIMAL. It is literally the smallest and most insignificant portion of the pcv system since blow-by gasses and crankcase pressure is MINIMUM during that situation.
Oil aspiration during through the pcv valve during that period is due to mis-configured system, poor understanding of the difference between flow rate and pressure. Since the engine- whether a 2000hp or 200hp engine is at idle or cruise- both will produce a very very small mass of blow-by gasses compared with WOT gasses which is considered NEGLIGIBLE during operation, i.e. 2000hp engine needs 10hp to cruise, a 200hp engine need 10hp to cruise: it is the same power output so oil aspiration (if any) will be the same (negligible) when the system is configured properly.


. Under boost in this configuration, the PCV valve is closed, which is where your turbo intake comes in, helping to evacuate the crankcase when the PCV valve is shut. Your turbo intake becomes the only available source of negative pressure (though very little if you have a high flowing air filter).

Why you talk about it here and above claim it never comes that way from the factory? You must have made a typo?



I really don?t understand how you?re missing all of my points. This isn?t hard stuff to understand, you?re just refusing to acknowledge how these systems are setup or their flaws.

Based on your writing I believe you are blind to how the system is truly setup and how it should work. You do not understand some key points about oil molecule behavior, engine seal performance, and system flow vs pressure. It is not uncommon...


Do you know VW TDI engines have a habit of running away because they pool so much oil in the intercooler? Where could this possibly be coming from on a healthy engine?!?!?!. The CCV system on that engine is a hose with a spring loaded flow regulator routed from the valvecover to the turbo intake. But but but but it was engineered that way, it shouldn?t do that right? Well it does, because no baffling system is perfect.

Every turbocharged engine will find oil inside the intake pipe leading to the turbo intake. All skylines and all supra engines do it. All sr20 engines do it. It is very good to find a slight oil coating there! The engineers didn't design inadequate systems or inadequate baffles; the oil quantity which collects in those ducts on factory air-filter engines is negligible and should be routinely cleaned during 50,000 to 80,000 miles maintenance intervals to remove sticky carbon buildup (heavy chains which collect over time while lighter chains move on). It was determined by the engineers that those small quantity of oil which slightly coating the tube and compressor wheel on healthy, factory air filter engines (i.e. significant pressure drop) will improve the lifespan and performance of the turbocharger as a fine, delicate coat of oil is literally desirable in those areas. Oil molecules are able to fill small gaps and imperfections in the materials which assists in smoothing airflow at high flow rates, and protects against oxidation- it prevents interaction with atmospheric contents which would alter the materials of the turbocharger over time.
--> Working as intended!!

[Kingtal0n]

Since you are one of the smartest people on this forum I think you have potential to fully understand some things. That is why I spend my time to write extra. I wrote this elsewhere but I figure you don't read all the links.

Lets start with this
I've seen data logs of crankcase pressure on my old shop?s wetsump 1100whp 4G63 with only atmosphere crankcase ventilation. 2-3psi. Wooptie fuckin do.

yes, most vented setups for performance engiens see 2 and 3psi of crankcase pressure. It's easy to say 'big deal' and move on.

Yet. With over ten years of chemistry & physics courses with 20 years of wrenching I have learned a couple things about oil molecules and engine seals.
All engine seals leak. If you install a brand new seal, then let oil sit on it, eventually the seal will age, and oil will begin to leak.

So there is a time limit from the moment you install a seal.
Oil molecules are very small, especially uniform synthetic variety. They gradually worm their way into/under/around oil seals over time.
The only thing that can speed them up, is heat and pressure. Higher temperature causes oil molecules to become more lively, think melted butter vs solid butter. Oil and butter are almost identical. The warmer the butter, the warmer the oil, the more easy it can fit through an engine seal or other tight spaces. In general.
Also, oil tends to pack into spaces, like butter can. When the engine cools off, imagine you cool liquid butter to a more solid or viscous state. it will pack rather well into a corner.
Then, when the engine heats back up, those tightly packed oil molecules start to expand and REPEL each other. So they start forcing their partners away; DEEPER into the oil seal crevice. Each time they pack and unpack they are forced deeper and deeper into the seal.
The other force which assists them is PRESSURE. For a simple example, put a tiny hole in the bottom of a water bottle and watch it drip out. Then, apply some pressure to the top (1psi from your mouth) and watch the water speed up from a drip to a stream.

That 1-2-3psi of crankcase pressure is applied to those oil molecules inside the seal crevice, and it speeds up their progress. If you hook an air compressor set to 2psi to the crankcase and walk away- the oil seals will leak MUCH sooner than if left at atmospheric pressure.

The only thing that can slow down the progress of those hot oil molecules which invade the seals, is PCV. That is the main purpose of PCV, to help pull oil molecules out of crevices, to help remove them from attacking and entering the oil seals and oil passageways around the engine. PCV is what keeps them from leaving the crankcase.

But PCV is not a flow rate. PCV is a PRESSURE setting.

That is why so many systems fail or seem to be insufficient. People modify their engines with high performance air filters and fail to adjust the system to regain lost pcv action. It wrecks the pcv functional pressure of the crankcase.

PCV is a setting just like boost pressure- it must be logged, calculated, and set manually anytime you adjust anything in the intake air pathway. If you alter the air filter to the engine- you must adjust the pcv system orifice and flow to regain the lost pressure of the high flowing filter. There must be some form of pressure drop or pressure will not be controlled and oil will escape and invade anywhere it can.

If you are putting it together now you may start to realize those engines which seem to aspirate oil to their intake manifolds, and fill oil to the intercoolers, all had high performance air filters or no air filters, and original or disturbed pcv hardware.... Yes there is a connection

[PoorMans180SX]

You lack reading comprehension. It's like you can only understand one sentence at at time and ignore the rest of the paragraph.

The PCV valve is not connected to the intake of the turbocharger. That's what I was saying.

If you've ever measured the pressure drop in a performance air intake, you'd know it was exceptionally small, much lower than the vacuum in your intake manifold at idle and cruise.


The intercooler must remain OIL-FREE thus a healthy engine cannot send any oil to the intake manifold if the oil cannot reach the intercooler.



Every turbocharged engine will find oil inside the intake pipe leading to the turbo intake. All skylines and all supra engines do it. All sr20 engines do it. It is very good to find a slight oil coating there!

So which is it, oil free, or with an oil mist coating? Sounds like some bullshit you made up.


If you are putting it together now you may start to realize those engines which seem to aspirate oil to their intake manifolds, and fill oil to the intercoolers, all had high performance air filters or no air filters, and original or disturbed pcv hardware.... Yes there is a connection

Take an intake manifold off a bone stock KA24DE or SR20DE or DET. It will be coated in oil film internally.

[Kingtal0n]

The PCV valve is not connected to the intake of the turbocharger. That's what I was saying.

If you've ever measured the pressure drop in a performance air intake, you'd know it was exceptionally small, much lower than the vacuum in your intake manifold at idle and cruise.


This is contributing to oil aspiration! This is why the engine is taking in more oil than it does with a factory air filter. This has been my point from the beginning.


So which is it, oil free, or with an oil mist coating? Sounds like some bullshit you made up.

Where is confusing to you?
Oil inside intake manifold: Should NEVER be oil inside the intake during short duration operation (< 30,000-40,000 miles or roughly three to five years). If there is, then the pcv system is not setup properly.

Oil inside the Turbo-Inlet (pre-compressor tube): There should always be a thin film of oil present here in all factory JDM engines with turbocharger, to keep those exposed thin metallic surfaces from oxidizing.
After 50,000 to 100,000 miles it can be washed out just like factory intake manifold to remove heavy chain deposits (sticky tar-like goop that collects over long time 5~ years of daily operation).

Clear now?


Take an intake manifold off a bone stock KA24DE or SR20DE or DET. It will be coated in oil film internally.

After 50,000 to 100,000 miles this is to be expected of course in all engines. No matter what kind of tube is placed between the intake and crankcase, some oil will always enter, the tube can be discarded or the intake can be washed. A quick wash will clear the intake out if the tube is short and kept OEM. Intake manifold sections are designed to be very easy to remove and inspect and clean. This is not an issue for healthy engines in the hands of capable mechanics of routinely serviced vehicles. The oil residue accumulated here during 50,000 to 100,000 miles is negligible and will not affect engine operation. Any significant oil coating is due to improper use of the pcv system; it should never be enough to reach the engine valves.



I am trying to lead you to a conclusion by making very obvious, rhetorical remarks.
->You know where the pcv valve is but refuse to see that is cannot possible pass oil to the intake manifold unless the pcv system is installed incorrectly. Expecting it to remain absolutely clear for 10+ years without maintenance is unrealistic;
->You see that performance filter provide little pressure drop but refuse to see that is the root cause of oil aspiration and oil accumulation. The pressure must be adjusted post-air filter to keep the crankcase clear of combustion gas which contaminates engine oil and allows it to leave the crankcase.

Oil is a variety of heavy carbon chains. As gasoline and blow-by gasses mix into engine oil, and as mechanical shear forces from the engine chew engine oil, light chains of gasoline solvate with lighter damaged carbon chains of engine oil and together these are able to evaporate easily and go wherever they please. So all of the pcv parts can be present: pcv valve, tubes, lines, etc... and yet if you do not measure and maintain the pressure drop of 1 to 3" Hg it will not function to keep these light chains under control and engine oil will easily escape.

The goal of the pcv system is to remove those lighter chains due to combustion gas before they can interact with engine oil, before they can dilute engine oil or facilitate breakdown and solvent interactions with heavy chains. There must be suitable flow and low enough pressure. Oil, like water, and all liquids, has a specific partial pressure for evaporation content. If the required pressure is not met (1 to 3" Hg) the light chains will not be pulled from the engine oil and this will lead to oil aspiration (engine oil going places like the intake manifold, more frequently).

When a free flowing air filter is used, it disrupts the pcv system so that the light chains are able to interact more fully with engine oil. This causes oil to easily leave the engine and enter the intake manifold through the pcv valve during innocuous cruise/idle situations.

Finally what gives you away is disregard for 2psi of crankcase pressure. the pcv system in wet sump operations only applies a negative pressure of approx 1 to 1.5psi (1 to 3" Hg). The importance of -1.5psi is paramount to healthy engine operation; therefore 2psi of blow-by crankcase pressure is absolutely horrific, catastrophic in nature, by comparison.
In other words, if the pcv system revolves around -1.5psi then the idea of 0psi or 2psi is twice and four times as bad for the engine, respectively.

[PoorMans180SX]

So your solution for a high performance engine is? Enlarged orifices? Careful testing and analysis?

I can guarantee you that the system I'm building will keep oil out of the intake and intake manifold. It happens to include two catch cans. Are you just saying that the catch cans are extraneous? That each and every engine has an ideal setup that doesn't include catch cans regardless of power level?

To be honest, I don't care about "corrosion" in my intake system, I'd rather have zero oil in it than risk it reaching the combustion chamber.

[Kingtal0n]

So your solution for a high performance engine is? Enlarged orifices? Careful testing and analysis?

I can guarantee you that the system I'm building will keep oil out of the intake and intake manifold. It happens to include two catch cans. Are you just saying that the catch cans are extraneous? That each and every engine has an ideal setup that doesn't include catch cans regardless of power level?

To be honest, I don't care about "corrosion" in my intake system, I'd rather have zero oil in it than risk it reaching the combustion chamber.

For oiling the engine's parts, It is primarily the turbo you should worry about. Most of the other parts receive their own share of oil as necessary. Actually all turbochargers mix some of their oil supply with incoming air, there is nothing you can do about that. For example the engineers at Borg Warner warned me not to inject water pre-turbo because it will enter the turbocharger's oil supply and get into the drain to the oil pan.


Lets go over some high performance aspects commonly overlooked by novices and 'enthusiasts' (most of us are just enthusiasts without 'real jobs' in this field) Unfortunately, owning a shop or working on race cars as a mechanic/tuner is not a 'real job' in the field of the engineering car parts for longevity and performance. Manufacturers which produce those parts hire engineers (e.g. Borg Warner staff who design turbochargers) may posses fundamental engineering book-work knowledge which makes certain aspects 'common sense' which to many enthusiasts remains a mystery, we will now discuss some of those

1. exposed metal of any kind should NEVER be in contact with atmospheric contents as it will oxidize. Even aluminum and stainless materials will oxidize. Metal of all kinds is constant jeopardy, and the tighter the space, the thinner the materials, the more risk (i.e. compressor blades and housing distance). This changes the surface of the compressor wheel, and housing over time, atmosphere causes pits, grooves, essentially eating away at the surface, 'rusting' it. Therefore, all turbo-compressor wheels need some oiling, their blades, shaft, housing, either spray it in there manually or let the crankcase supply a fine coating. Never let it dry out as the atmosphere will attack it, change it.


2. air filtration is the other key to success. A high quality paper air filter is absolutely requirement for any 'daily driver' (longevity) setup. Atmosphere contains all manner of biological entities; fungus & pollen are found everywhere in the world's air, for example, they are live cellular structures which contain the materials of life: Chlorine, potassium, molybdenum, iron, sulfur, nickel, sodium, chromium, etc... as well as myriad complex structures containing long chain carbons and carbohydrate/proteins as with any living cell. It is typical in chemistry to apply HEAT and PRESSURE to force chemical reactions between such molecules to produce by-products. An internal combustion engine provides both: HEAT and PRESSURE to these substances thus allowing a wide range of conglomerates to form within the combustion chamber, a soup of random, sticky substances which are entirely unhealthy to an engine of any kind.
Also remember there are the dust, dirt, sand, glass-like inhalants which scar and scratch the engines parts as they collide with high speed, pitting and eroding the metal of an engine's internal parts.
None of that should ever get inside an engine. Air filtration is an extremely important, massively overlooked aspect of high performance engines and longevity solution. Filtration is practically the only thing saving an engine from erosion internally and to keep parts from collecting reacted byproducts which hinder function and performance.

Its not that hard, really. Keep your exposed metal parts oiled (common sense) and keep the air super-filtered (common sense). This goes for machines of all kinds. The more expensive, the longer you want it to last, the better oiled and cleaned it had better be. Atmosphere is NOT your friend. Even for breathing, the human body and it's lung tissue will last longer if the air is cleaner. Its obvious when you say it but nobody ever thinks about it when they go outside without a mask because our society isn't advanced enough and the air isn't filthy enough yet to make it mandatory to purify the air we breath. But this is changing... you may have noticed... air quality and recognition of what is in the air is becoming more prevalent. And it will not stop, the future holds many changes for humans living, breathing, you will see more filtration and more high quality masks over time.


So your solution for a high performance engine is? Enlarged orifices? Careful testing and analysis?
Most of the solution is above, keep your exposed metallic surfaces oiled and keep the air as super filtered as possible (and oil filtered, obviously).

the other end of the solution is simply to measure the crankcase pressure. I'd hardly call that careful testing and analysis. Use a 2-bar map sensor ($12 ebay) and log the crankcase pressure (Arduino can do it for $20, even HPtuners EGR 0-5V input can do it free using stock ECU on GM Engines) And any stand-alone can do that. Very inexpensive, very powerful tool.

Once you log the crankcase pressure it will be obvious what needs to be done, sort of haha.
Airflow through orifice can be calculated using simple engineering formula (online or by hand) but that is unnecessary with some common sense approach, I will elaborate now, this is the common sense method:

Size of orifice and pressure difference through a nozzle does not need to be a differential equation; its a steady state single-value since our target pressure never changes. This would be confusing if you don't know the GOAL. Luckily I will tell you the goal and explain why it is the goal. I am not trying to hide or cover details, I will use plain English and simple words so that all can understand without being an engineer or knowing engineering terms.

The goal is to produce the desired pressure drop of 1 to 3" of Hg at all times while also minimizing idle/cruise flow rate. This is an unspoken aspect to generating this pressure drop which is absolutely critical to understand.
I will lead an example

We have 3 variables to determine steady state pressure for idle cruise: fresh air inlet diameter, outlet diameter, and pressure difference.
pressure difference:
Our fresh air inlet is always assumed atmospheric (for idle/cruise there is no air filter restriction @ ~10hp or less engine power) so lets set that to 14.5psi
Our intake manifold is lets say 15.3" Hg vacuum (-7.5psi) So 14.5 - 7.5 = 7psi intake pressure absolute
So the difference in pressure is 14.5 - 7 = 7.5psi difference

Orifice diameters, Intake manifold pcv orifice and fresh air orifice we will adjust to show the effects now:
-----Idle/cruise pcv action-----
With:
Fresh air orifice diameter: 0mm & Intake manifold pcv orifice diameter: 10mm
Resulting crankcase pressure = intake manifold pressure of 7.5psi absolute (15" Hg)

Discussion: obviously if we block off the fresh air vent completely (0mm) the crankcase will be pulled down to intake manifold pressure and the engine's oil seals will be damaged, maybe even pulled into the crankcase.
This example shows us that the diameter of the fresh air vent is CRITICAL. Too Small and the engine will be damaged.
Next, lets oversize the fresh air vent.

With:
Fresh air orifice diameter: 25mm & Intake manifold pcv orifice diameter: 5mm
Resulting crankcase pressure = atmospheric pressure 14.5psi absolute (0" Hg vacuum in the crankcase)

Discussion: Now we see that when the fresh air inlet diameter is too large, there can be no PCV action, no vacuum is present in the crankcase. Note that there can be a very high FLOW RATE through the crankcase, that intake manifold suction is still PULLING on the crankcase to remove blow-by gasses. However, without the sufficient pressure drop, there is no true PCV action, there is no OIL-SEAL protection, there is no Reduction is light chain hydrocarbons due to partial pressure of evaporation, there is no prevention of oil aspiration to engine orifices, no pressure drop to pull oil from engine crevices.


With:
Fresh air orifice diameter; typical: 12mm & Intake manifold pcv orifice diameter: 3mm
Resulting crankcase pressure = 13psi~ (approx 3" Hg vacuum)

Discussion: This random example (not exact orifice diameters, just for example) is showing us that by adjusting the Fresh air inlet diameter, AND the pcv orifice diameter (often set very small by the pcv valve) we can achieve the correct pressure drop inside the crankcase for idle cruise. 0.5psi to 1.5psi is fine. This will protect oil seals, help keep oil inside the engine, and it will facilitate the removal and evaporation of light chain hydrocarbon byproducts of combustion (mostly gasoline fragments which would otherwise dissolve into engine oil).

Another key idea here is that we want our PCV valve orifice as SMALL as possible, the SMALLEST possible diameter to generate the necessary vacuum in the crankcase.
Why?
1. because in the event of a fresh-air inlet clog, the very small orifice will not provide enough powerful suction to damage the engine's oil seals. A large orifice can easily damage the engine's seals, as intake manifold suction is very powerful.
2. because the smaller the pcv orifice, the fewer air molecules per unit time can pass through it, which means fewer oil molecules "go along for the ride". In other words, smaller orifice = less oil aspiration over long period of time. You will see less oil inside the intake manifold after 50k to 100k miles using the smallest orifice.


Now the key to why catch cans should be avoided. A catch can adds crankcase volume. The very small pcv valve orifice we are using will take TIME to pull the crankcase down into a vacuum state, and that TIME is dependent on the volume of the crankcase.
Therefore, by adding a catch can (or any extra volume to the crankcase i.e. huge lines and cans) is going to slow down the ability of the intake manifold and small-orifice of the pcv valve to generate substantial vacuum inside the crankcase.
Basically, we want the SMALLEST crankcase volume possible because just like when using vacuum hoses, the vacuum signal will be STRONGEST when the volume is SMALLEST. Which allows us to also use a very small PCV orifice diameter.
Does this start to paint a picture? The small orifice which can protect the engine is only going to work when crankcase volume is MINIMAL. That means NO extra lines, NO catch cans, NO extra volume attached. By using those devices you are creating a situation where the PVC-orifice would need to be enlarged, which will allow MORE oil to pass the orifice and a STRONGER pressure signal from the intake manifold which can be dangerous to the engine's oil seals if the fresh air inlet ever becomes clogged. Likewise, we wish to use a slightly OVERSIZED fresh air inlet tube/orifice since this will protect the engine when that hose and orifice becomes wet with oil and gradually collects carbon deposits.

Finale:
Our goal is to MINIMIZE the potential for failure and MAXIMIZE the rate of pressure change inside the crankcase, thus we should use the smallest diameter PVC-orifice and smallest crankcase volume possible, with a slightly over sized fresh air inlet orifice.


---------- WOT pcv action---------
This is simpler than the above situation. Since the pcv valve is CLOSED, we only have two variables:
1. Fresh air inlet diameter (as above, same hole) as before, keep slightly oversized.
2. Air filter pressure drop (the pressure behind the air filter, where the fresh air inlet hose is attached on all factory turbo engines)

The size of the orifice in this case is set by the previous example, since a large enough orifice to supply the crankcase flow during idle/cruise through the pcv valve is usually sufficient at WOT on all but the most 'leaky' of bottom ends. In which case the choice must be made whether to conserve idle/cruise pressure drop or to focus on the WOT pressure drop.

So we will ignore the orifice diameter and focus on the pressure drop itself.

The pressure drop at WOT is set by the air filter. Since there is always some gradient Pressure (the difference in pressure from the post-air filter tube to the actual crankcase) we always shoot a little lower at the post-air filter region.
Our target post-air filter pressure is as before: approx 3" Hg (about 1.5psi of pressure drop is healthy). This is enough post-filter pressure drop to pull the crankcase to approx 1psi of vacuum (2" Hg~) minimum.
This pressure drop does the same thing as before, it protects the oil seals, keeps oil inside the engine, and removes the blow-by gasses which would contaminate the engine oil.

Measurements taken here (just off the valve cover for example) are also a valid indicator of engine health. The same orifice and air filter generates the same pressure drop everytime the engine goes to WOT. If the pressure suddenly increases, it is a warning that something in the bottom end is wrong. This is one of the most powerful prediction tools we have at our disposal (monitoring crankcase pressure at WOT) as it DIRECTLY ties engine health to some number on a gauge which can be repeatably relied upon to tell us whether the engine today is running exactly as healthy as it was yesterday.

And to repeat this monitoring can be done for less than $50 ($12 map sensor and a $20 arduino). even if one does not have access to a stand-alone.

How does one "set" the pressure drop using an air filter?
Luckily, by using a high quality paper air filter (many aftermarket companies such as AFE provide re-usable paper style air filters of any shape, while OEM paper is the best it can be difficult to fit a large enough one) the paper element creates the pressure drop when the filter is sized correctly, within some reason. And by simply driving the vehicle, the filter will collect a bit of dirt and the pressure drop will increase (more post filter pressure drop over time) so it sort of takes care of itself.
The factory papers for example start off around 0.5" Hg pressure drop for the first 200-500 miles. Then by 500miles usually you will see 1" to 1.5" Hg of pressure drop. Finally by 3000miles or so you will see 3" to 4" Hg of pressure drop... time to change the filter. This is by design, and it is a very creative aspect the engineers are using to protect the engine.
Explain:
As the engine mileage increases and the air filter becomes dirty, the post filter pressure drop also increases as explained above. Why is this so important?
Well, as the post filter pressure drop increases, that means the engine is breathing more and more from it's own crankcase. In other words, It starts to clean itself better over time, it starts to protect it's own oil supply more and more as time goes on.
This was done on purpose by the engineers who designed the engine. They assume that if somebody is neglecting the air filter, then they are probably also neglecting the oil filter and other maintenance of the engine. Therefore, the most important thing for the engine to do when it is being neglected is to start protecting itself, to start protecting its remaining oil supply and internal cleanliness. Therefore, the effect of 'quickly clogging paper filters' is entirely calculated to protect the engine even while it is being neglected by the owner.

I hope this has been informative and helpful in your journey to a truly clean high performance engine land

[jr_ss]

This fucking guy literally sees only black and white. There are no grey/gray areas with him. Because the engineering book says it shouldn’t happen doesn’t mean it can’t. All engines have blow by. There isn’t a single engine on this planet that has 100% sealing capabilities.

Guess what, that oil cloud in the bottom end of an SR has a huge galley to make its way to the front of the motor and up, into the head. I.E. out of the VC.

You’re a smart dude, just argue all the wrong points.

There is plenty of data out there than a vacuum pump or vacuum operated catch can system increase HP by sealing rings better. All S13 motors came with a catch can and weren’t you arguing that a 2liter VET motor can’t make 370ftlbs of torque?

Guess what, things can happen outside of your mathematical calculations.

[burnsauto]

of all the hills to choose to die on...catch cans...

[slider2828]

Evil Energy... Amazon brand, but I like it and it is cheap!

And please don't vent to atmosphere. that is garbage

https://www.amazon.com/EVIL-ENERGY-Universal-Reservoir-Aluminum/dp/B081N392BN/ref=sr_1_5?dchild=1&keywords=oil+catch+can&qid=1598643786&sr=8-5

[PoorMans180SX]

of all the hills to choose to die on...catch cans...

Come on Jared, I?ve always been over the top, you remember. I used to believe in God! Hahaha.

[silviaks2nr]

Not sure what all the drama is about. If you don't want one then you don't have to run one...

Dukefab makes a nice one. I decided to make my own based on his design but which also covers the ugly wiper motor. Need to update my build thread now since it's been a minute.

https://i.imgur.com/CoG21Xc.jpg
https://i.imgur.com/QEU2AxX.jpg

[burnsauto]

i remember our talks over shitty pizza about catch cans, and how to build a system that actually works on the SR, you'd need two cans..or a centralized one that utilized the right and left side of the engine's openings.

I always liked Signal auto's design. Simple and clean..

https://i.ibb.co/pKxv5fr/D1-15.jpg (https://ibb.co/C9z5Dbs)

[S14rebuild]

i remember our talks over shitty pizza about catch cans, and how to build a system that actually works on the SR, you'd need two cans..or a centralized one that utilized the right and left side of the engine's openings.

I always liked Signal auto's design. Simple and clean..

https://i.ibb.co/pKxv5fr/D1-15.jpg (https://ibb.co/C9z5Dbs)


Signals twin s13s are what got me into s-chassis and drifting! Omg bringn back memories....

[Kingtal0n]

Completely unnecessary, ugly, and a clear indicator that the owner has no idea how an engine works.


Oh, people love them though. Everybody loves how they look. It doesn't matter if they help or not... to normal people its an accessory. Like a chain around your neck, useless, pointless, but it looks pretty. Except that it degrades PCV function and speeds up oil aspiration/wandering/invasion into seals by increasing crankcase volume unnecessarily. Something so simple too.

You measure intake manifold pressure but not crankcase pressure? That is a joke. Crankcase pressure is more important.


S13's do not have catch cans lol. That black can is not a CATCH device, it recirculates oil back to the oil pan, acting as an oil-air separator. Which is really makes it a circulation improver. Oil should never STOP moving anywhere, just like blood in the body should never STOP anywhere. When oil/blood stops what happens to it? It coagulates, it solidifies, it turns to hard deposits and then you have a nice fat chunk which can break off eventually and float down stream, clogging an artery. Destroying the body/engine or part of it.


Let me run this one more time. Last time I try, this time I won't use a glib demonteaur (I wont try to make you think I'll just spoon feed)

When the engine goes into boost/WOT, it must have specific vacuum present 1-3" Hg inside crankcase. You must measure it. All wet sump applications need this.
This vacuum is what protects the oil seals and oil baffles. Just look at what happens when a piston ring breaks: Oil comes gushing out of the baffle. The opposite of what you want, Makes sense? No need formulas or numbers here to understand.

So lets say you run any engine at 0psi or 2psi instead of 1-3" Hg at WOT. Atmospheric vent or whatever.
You go WOT and no oil comes out. So everything is fine?
Wrong. Oil is being pushed into the oil baffle. Little by little, everytime you go WOT, more oil goes into the baffles, more is pushing into oil seals, the seal and baffle is being gradually invaded.

Main point(if you read nothing else read this)
That is why you find oil inside the intake manifold... First, the WOT condition pushes oil into the baffles, THEN the intake manifold suction vacuums up that oil from the baffle later. The oil that would NOT be inside the baffle in the first place if the engine had the correct crankcase pressure to begin with at WOT! A catch can is just mopping up your poor understanding of performance engine dynamics at that point. Can't figure out how to use a $12 2-bar map sensor? that sucks

To put it another way
Removing PCV is like start cigarette smoking. Lets say I disable the WOT pcv tube one day, just pull it off. Will I see oil immediately? No of course not. Just like with tobacco, It takes multiple runs, many times at WOT over a long period of time to push oil bit by bit into seals. Eventually the oil will invade every crevice and each seal and baffle will begin to show signs of leaking oil. The effects are not immediately apparently. Fresh engines appear to be fine at first. But just like smoking you can't quit one day and expect immediately improvements either; in fact the damage is often irreversible, you need to remove the old seals, and replace them. Wash out the baffles fully, replace all the lines, inspect the whole system and clean it back to normal.

I spend so much time on this because its the most important aspect of high performance engine theory there is. That highest high of knowledge which marks you a true enthusiast of mechanical engine performance: is cleanliness, and it starts inside the crankcase as a vacuum which keeps the engine's seals and baffles clear of oil.

[cured13]

S13's do not have catch cans lol. That black can is not a CATCH device, it recirculates oil back to the oil pan, acting as an oil-air separator. Which is really makes it a circulation improver. ...

... vacuum is what protects the oil seals and oil baffles.

... That highest high of knowledge which marks you a true enthusiast of mechanical engine performance: is cleanliness, and it starts inside the crankcase as a vacuum which keeps the engine's seals and baffles clear of oil.

I'm totally in for cleanliness of air passage from the air filter to the throttle body and appreciate your passion and persistence.
I also agree that all these huge shiny catch cans and meters of hoses connected to them change volumes and pressures in PCV system which might actually change things for worse.

I still want to prevent having oily deposits before throttle plate and was considering replacing "that black can" with slightly smaller can to keep volumes similar to stock. And, ...
there is a restrictor in the hose connected to that "T" on valve cover to regulate the flow and pressures I assume. I think that removing it and adding small catch can between "T" and intake pipe will help keep things more clean. The only problem and question is how to keep that catch can accurately restrictive for healthy engine?
So, instead of that small filters that vents to atmosphere a good designed catch can should have means to monitor pressure and vacum, and to adjust baffling accordingly.
Am I right, or should we just keep all system stock and let intercooler collect all oil vapors like in VW and Audis lol.

[Kingtal0n]

I'm totally in for cleanliness of air passage from the air filter to the throttle body and appreciate your passion and persistence.
I also agree that all these huge shiny catch cans and meters of hoses connected to them change volumes and pressures in PCV system which might actually change things for worse.
Good!
Yes, worse is a possibility. Anything we do can make it worse.
The key is to simply MONITOR with a gauge. Either using a 2-bar map sensor can work, or a gauge which reads in inches of water like this
https://www.ebay.com/itm/Dwyer-Magnehelic-0-60-Inches-of-Water-Pressure-Gauge/143500922484?hash=item2169524e74:g:1uEAAOSwGzNeHOD B

60" of water = roughly 2psi so this is a very accurate high resolution gauge for monitoring crankcase pressure (example) in case you can't log the 2-bar data.


I still want to prevent having oily deposits before throttle plate and was considering replacing "that black can" with slightly smaller can to keep volumes similar to stock.

Fortunately there is no way for oil to make its way to the throttle plate because it would have to go through ten miles of intercooler plumbing. That is the benefit of running a turbo-intercooler. So this is a non-issue, oil should not appear anywhere near that location even on blown engines, it would just flood the intercooler.


And, ...
there is a restrictor in the hose connected to that "T" on valve cover to regulate the flow and pressures I assume.

Correct the factory includes a very specific size orifice in their valve-cover to pre-compressor inlet tube in order to facilitate pressure drop of crankcase! This orifice can be adjusted to accommodate modifications you may make the pcv system.


I think that removing it and adding small catch can between "T" and intake pipe will help keep things more clean. The only problem and question is how to keep that catch can accurately restrictive for healthy engine?

Well as I stated above, some oil residue is desirable to coat the inner tube of the pre-compressor region. The pipe there and the compressor wheel can benefit from the oil coating, it alters the reynolds number of the pipe and allows a more laminar condition, less turbulence due to less pipe roughness. I recommend manually oiling the compressor wheel and inlet tube prior to running fresh setups. In fact many turbo manufacturers compressor wheel hardware right out of the box will rust instantly if you do not oil it immediately, I know mine did before I knew better.


So, instead of that small filters that vents to atmosphere a good designed catch can should have means to monitor pressure and vacum, and to adjust baffling accordingly.

Generally, healthy engines don't really need "better" baffles. They just need a healthy pressure drop at WOT to keep from pushing oil into the baffle in the first place. Many people install high-flow air filters which negates the factory intended WOT pressure drop, and this allows oil to invade the baffle, thus working its way to the intake manifold and gradually pushing through the oil seals around the motor, causing leaks.

If we look at an engine with a broken piston, we see that it gushes oil when it goes WOT.
That is, crankcase pressure (blow-by) is pushing oil right through the baffle.
So it stands to reason that crankcase pressure is what is pushing oil into the baffles in the first place. I don't know why this is so hard for people to understand.

So if positive pressure (Broken piston, etc...) can push oil OUT of the engine, THROUGH the baffle,

What do we think logically that negative pressure can/will do for the engine?

Answer: A pressure drop inside the crankcase will pull oil INTO the engine, it will pull AWAY from the baffle. It will pull oil OUT of the engine's seals, or at least impede the progress of oil somewhat.

This doesn't take calculations, just a logical conclusion based on experience. I see pressure pushes oil out of the engine, therefore, vacuum must do the opposite. Does it make sense?
If we look at engines with vacuum pumps, their success depends heavily on the engine seals being superior, they need very strong seals to resist the high vacuum from the pump. And the reward is a superior RING seal, and more engine HP.

What many people forget is that the crankcase pressure DIRECTLY influences ring behavior. All this talk of oil flowing into and out of baffles and everyone is ignoring the fact that blow-by gasses are impeded by the crankcase pressure, e.g. when there is a positive pressure in the crankcase, it will hinder the piston ring performance, it will prevent blow-by from gaining access to the crankcase via the second ring, blowby gas pressure differential becomes elevated between the first and second piston rings, which leads to all manner of piston ring issue, poor sealing, flutter, whatever

Its so hard for me to understand how people can see what vacuum pumps do for an engine and then not to be able to put 1:1 together with their own crankcase systems.

-----
Here is another way to look at our situation, typical evaluation

The engine starts out with a correct filter and pressure drop from the OEM factory.
Along comes an unaware enthusiast and he uses a high flow air filter to gain 5% HP or whatever by eliminating PCV function and ruining the WOT pressure drop.
Now the engine will push oil into it's baffle system at WOT and the intake manifold will become soaked saturated over time with oil as a strong manifold vacuum will pull all that oil right out of the baffle after it's done pushing oil at WOT. Condition similar to a partially broken piston ring.
The high WOT pressure further hinders ring function so blow-by is increased above natural quantities, i.e. not only is there MORE blow by, there is now even MORE oil going into the baffle system.

Then he complains about the oil in the intake manifold a couple weeks later "holy cow look at all this oil! OMG I need a catch can... whats wrong with those stupid engineers??"
So along comes the catch can, which is going to collect a stagnant reservoir of engine oil over time. Everytime the engine starts the can heats up with 200*F oil and everytime it cools, water vapor from combustion can settle "condense" inside the can and mix with engine oil, and this will get re-heated everytime the engine is re-warmed and mix back with the existing oil supply. Thus the stagnant can quickly acidifies and 'waters' down the engine oil (its alot easier for water molecules already dissolved into engine oil to move through engine oil), accelerating the oil's destruction, increasing the rate of oil consumption and engine wear over time if the oil isn't constantly changed at higher than typically necessary intervals. This is plain, due negligence for an engine, and adds unnecessary cost.
And if that wasn't enough, the additional volume of the added can is making it more difficult for the existing pcv system whats left of it, to pull a pressure drop on the crankcase, ruining ring function and increasing the blow-by and oil aspiration further. The larger catch can is making matters worse all around, its like treating the symptoms of cancer instead of preventing the cancer in the first place, i.e. they gave the engine cancer by eliminating WOT pcv pressure drop and then treated the symptoms with a harsh drug(stagnant catch can volume) that further damages the engine over time (chemotherapy).
Instead they should remove the can, and induce the proper PCV pressure drop at WOT, and the cancer won't be there in the first place. You won't need a can if the WOT pcv pressure drop can prevent oil from flowing into the engine's baffle in the first place. Just don't forget to clean the baffle out, you know once every 100k or so is fine, sometimes 200k. Its not rocket science, cleaning a valve cover, if you can install a can you can wash a valve cover once every 10-20 years.

[Kingtal0n]

The only problem and question is how to keep that catch can accurately restrictive for healthy engine?


I forgot to comment on this fully. Not all engines are turbocharged, and would those will not benefit from any oil coating. This is a good line of thinking which I believe many engineers have also reasoned with, since we cannot prevent 100% of the oil from exiting the crankcase at WOT for 200,000 miles, and many consumers will not be savvy enough to realize the need to wash their intake plumbing every so often (sigh), why not design a very small "catch" device which can be easily cleaned and is small enough to not impede WOT pressure drop?

Such a device does exist, I've seen it. Here is one such company which offers that device.
https://i.postimg.cc/DzJwmHQs/smallcatch.png

They make some catch devices for corvettes, naturally aspirated, which will reduce or eliminate the oil which can gradually coat the throttle body (since there is no turbocharger or intercooler plumbing).
Its not really a can. Its just a small air/oil separator, and excellent idea and minimal volume. The same company also offers inline restrictors to correct pcv function as necessary.

So you are correct to imagine such a thing. It is not such a bad idea. I am not against oil CONTROL. Its just that there are soooo many ways to screw up the necessary design of a PCV system... you really have to be a master enthusiast or an actually experienced+engineer to relate the details... volume, flow, viscosity of fluids, intended effect. And this is the most critical system on the engine in my opinion. It literally controls the quality of engine oil, the longevity of an engine, the leakiness or potential for oil leaks of the engine, the piston ring function, and the cleanliness of the engine's internals over a long period of time. It is the most important thing to understand about performance, and often the last thing, most highly neglected aspect of all that people will understand... if ever. Ironic

[RedSled]

So after all this back and forth with regards to catch can ,can someone give their views or experience with regards to vented catch cans vs sealed catch cans .

[zombiewolf513]

https://www.mishimoto.com/compact-baffled-oil-3-port-catch-can.html

[burnsauto]

I've used greddy ones in the past, but was never super impressed with the results, mainly because I never liked the idea of the oil never returning to the system. Instead I'm going to run this moroso oil separator and instead of having the drain at the bottom that's shut off, run a line that connects down where the factory line goes on the SR (ex mani side). I saw the piece at a moroso booth at FD a few years ago, it's a little larger than I expected, but a nice piece.

https://turn5.scene7.com/is/image/Turn5/14442?wid=810&hei=608&op_usm=0.8,1,10,0

[zombiewolf513]

If the petcock is open, youd pull vacuum from the oil pan

[burnsauto]

If the petcock is open, youd pull vacuum from the oil pan

hmm, so is there a check valve in the oem unit? I can understand that while under load, the turbo would create some vacuum, But really so much that I'd pull oil out of the pan? How does the OEM setup not do this? It's been awhile, so I may be wrong about this, but there's a line that comes out of the bottom of the block, goes to the OEM oil separator, another short line to the "T" on the valve cover (S13SR), then another hose that goes to the inlet for the turbo.

I was going to ditch the "T" fitting on the valve cover, run one line to the moroso tank from the V.C. , another line to the inlet tube for the turbo, then run another line from the bottom of the tank to the bottom of a block, to reintroduce the recovered oil.

I even made a little doodle of this and compared it to the OEM setup. If I'm being stupid, that's fine...not the first time. My thinking was the oil would get trapped in the separator under load, then off throttle , the oil would make its way back down to the pan.

https://i.ibb.co/QX0L1Vd/derpyidea1.jpg (https://ibb.co/0Q5TdLt)

[PoorMans180SX]

I've used greddy ones in the past, but was never super impressed with the results, mainly because I never liked the idea of the oil never returning to the system. Instead I'm going to run this moroso oil separator and instead of having the drain at the bottom that's shut off, run a line that connects down where the factory line goes on the SR (ex mani side). I saw the piece at a moroso booth at FD a few years ago, it's a little larger than I expected, but a nice piece.



This is kind of my plan, but I'm going to use the block vent to pull from. That will go to a catch can with a PCV valve in it, and then to the intake manifold. There will be a small drain that will go to the sump.

Then my welded -10 fitting to a different catch can, with a -10 line back to the turbo intake. This can will also have a small drain line returning to the sump.

If there's good airflow in the system, there's no way you should be able to pull oil up through the drains. Path of least resistance and all that.

[zombiewolf513]

Ah, i see what you mean now. No that would work as long as the return line is large enough for the air and oil to bypass eachother like the oem one is designed. You could have a multitude of issues if the crankcase vent/oil return line is too small or restricted by a 'U' shape in the line where oil could pool. Oil has to have gravity pull it back down into the pan

On second thought, you may need some kind of oil baffling inline for the crankcase side depending on how the can is designed. The oil vapers need to be consolidated from the air before it enters back into the intake

[burnsauto]

Ah, i see what you mean now. No that would work as long as the return line is large enough for the air and oil to bypass eachother like the oem one is designed. You could have a multitude of issues if the crankcase vent/oil return line is too small or restricted by a 'U' shape in the line where oil could pool. Oil has to have gravity pull it back down into the pan

On second thought, you may need some kind of oil baffling inline for the crankcase side depending on how the can is designed. The oil vapers need to be consolidated from the air before it enters back into the intake

Yeah I'm not sure what resides inside the moroso unit, from the shape, I'm guessing steel wool, which I'll try...if it doesn't seem to be working, then I'll change up the tank to one with something more substantial inside (actual baffle system).

It's just a street car, its nothing crazy. I'm not going for the end all, be all, solution. I just want to keep oil out of the turbo if I can help it.

[rightcoastimports]

http://www.eliteengineeringusa.com/flow-restrictor/

For those of us that don't have the factory restrictor (in my case never did)
what do you think of adding this in-line to the turbo with no catch can?

Also, i've never had the factory black air/oil sep. box either. So that means the crank case volume is less than OEM. Which means from all this jumbo i've read. my PCV system pressure is probably not ideal. what do we do here? especially taking into account running a "high flow air filter."

Honestly, reading that 21 page oil catch can thread and now this I don't know exactly what to do.. haha. Are we over-complicating things? not facing bottom end issues? not tuning accordingly?

I understand everything everyone is saying here and taking it into account on my current setup. Ive never interrupted the PCV valve, just replaced it once. This past year the car didn't get driven much.. but I did not run a catch can. stock turbo @ 12psi

[slider2828]

On the 21 page thing, that is really more towards track use / elevation change / and just more boost. I was running 19 to 21 psi on a 2871r and big elevation change like Laguna Seca or Sears Point or Thunderhill. So it depends.

I would love my catch to drain back, but problem is that I would need a check valve cause on the track, I am rarely off throttle or not on boost.

For street setup, just get the radium dual catch system and call it a day. Daily isn't going to do much, heck I would just run some form of air oil separator between the T and the crankcase and call it day. This is on the S13 T fitting. S14 and 15s you are fine.

So depends, if you don't drive it like REALLY hard and live only between 5k and 8k.... this isn't going to happen that often