SR Owners... More HP Easy Mod... Catch Can Setup

[hOngsterr]

i thought going with a s13.4 you wouldnt need a catch can?

[nismolvr]

Originally Posted by hOngsterr

i thought going with a s13.4 you wouldnt need a catch can?

Correct , After I installed my s13.4 cover my catch can has never seen oil! I just chose to leave my CC on.

[cotbu]

Originally Posted by hOngsterr

i thought going with a s13.4 you wouldnt need a catch can?

Changing the valve cover design isn't going to eliminate blow-by!

I think people don't understand the "crankcase vent", It's routed to the valve cover because the valve cover has provisions for evacuation. On the oem S14 valve cover, the oil that may come up from the crank case, will not make it to the intake like in the s13 config. The valve cover acts like and oil air separator, in the s14 and s13.4 configs.
So adding a catch can just insures there is no oil in the intake.

Originally Posted by slider2828

Hey Matej. I would put the pcv to the greatest vacuum source which is the intake/catchcan... To tell you the truth, so you can pull as much vacuum as possible. T'ing pretty much always reduce flows for any fluid and gases. So no T, but to catch can....

I think 10mm is large enough because might start pulling in oil if any bigger....

The valve cover is supposed to be low pressure (I know), but that's why the PVC blocks boost from entering the valve cover. So you could remove the pvc line from the intake manifold and route it to a sealed catch can and have it purge constantly. Will it be enough vacuum? IDK.

[Campos]

The best solutiion is to run a line from the valve cover to the exhaust with a check valve or pcv valve...honda guys have been doing this for years....just my $.02

[blu808]

That is one way of doing it but it will wear the rings excessively due to the negative crankcase pressure.

[slider2828]

Originally Posted by cotbu

Changing the valve cover design isn't going to eliminate blow-by!

I think people don't understand the "crankcase vent", It's routed to the valve cover because the valve cover has provisions for evacuation. On the oem S14 valve cover, the oil that may come up from the crank case, will not make it to the intake like in the s13 config. The valve cover acts like and oil air separator, in the s14 and s13.4 configs.
So adding a catch can just insures there is no oil in the intake.




The valve cover is supposed to be low pressure (I know), but that's why the PVC blocks boost from entering the valve cover. So you could remove the pvc line from the intake manifold and route it to a sealed catch can and have it purge constantly. Will it be enough vacuum? IDK.

Its enough ahahah....

[quickdiversion]

Originally Posted by BenFenner

Hey, sorry to bump this thread but it was brought to my attention by someone else on a Nissan forum I frequent more often.

There, I have a couple threads that try to fully explain the factory PCV system on the SR20 engine and I rate different modifications based on the following criteria resulting in an over-all rating:

• De-clutters the engine bay - Yes/Maybe/Unchanged/No
• Simplifies crank case ventilation system - Yes/Maybe/Unchanged/No
• Maintains stock prevention of crank case pressurization - Yes/Maybe/Unchanged/No
• Stops intercooler from acting as an oil separator - Yes/Maybe/Unchanged/No
• Helps remove more oil from the air - Yes/Maybe/Unchanged/No
• Help evacuate the crank case - Yes/Maybe/Unchanged/No
• Maintains or improves the stock flow capacity - Yes/Maybe/Unchanged/No
• Helps promote ring seal and prevent blow-by - Yes/Maybe/Unchanged/No
• Helps prevent oil smoke in exhaust - Yes/Maybe/Unchanged/No
• Helps prevent dip stick from popping out - Yes/Maybe/Unchanged/No
• Helps prevent oil leaks due to pressure - Yes/Maybe/Unchanged/No
• Helps keep intake track clean including throttle body - Yes/Maybe/Unchanged/No
• Helps keep intake manifold/plenum clean - Yes/Maybe/Unchanged/No
• Maintains or reduces amount of pollutants - Yes/Maybe/Unchanged/No
• Maintains prevention of un-metered air from entering the intake - Yes/Maybe/Unchanged/No
  

A final verdict is then given.




My point? Well, first off I wanted to congratulate the members in this thread who've figured out the system and how to improve that. That is no small task. Plenty of people make things worse when they start messing with this system. You who have it figured out, you know who you are.


Secondly, I wanted to touch on the PCV valve itself. The most recent posts in this thread mention the valve is quite literally a ball-type check valve. That is not the case. The valve is slightly more advanced than that, and information on it can be found here: Crank Case Ventilation fully explained. (Naturally aspirated edition.) - SR20 Community Forum - The Dash


And here' Nissan's diagram of it:
http://i160.photobucket.com/albums/t...Inspection.jpg





Thirdly, I wanted to touch on the factory restrictors that exist in the system. I noticed there was some talk about them, and pictures posted. I too was surprised to find both of them. Yes, there are two. One is in the small "PCV hose" that goes to the plenum (pics of this were posted), and the other one is sort of in the factory intake "boot. Here is a picture of that one.



The reason for these restrictors is hard to fathom, especially the second one in the WOT section of the PCV system. Since everything we know and have been taught is to maximize flow through that system. It just boggles the mind.


Maybe you've figured out why the restrictors? If not, the short answer is that it facilitates vacuum creation in the crank case. When at idle or low load, the PCV line on the plenum is trying to create a vacuum in the crank case. If there is no restrictor on the WOT section then the crankcase has full access to atmosphere (through the intake tract before the turbo or a filter venting to atmosphere on some modded setups). This makes it almost impossible to create a good vacuum inside the crank case. That's the main reason for the WOT line restrictor. I'm betting 95% of people who modify that section of the system have removed this restrictor. Now you have almost no vacuum at idle and low load situations.


The other restrictor? The one in the small PCV hose by the plenum after the PCV valve? I believe that is there to limit flow into the engine during idle so the engine doesn't get a large source of oxygen that by-passes the throttle plate and idle control valve. Without it, the engine could ingest a good bit of air at idle and there is no way a 850 rpm idle could be kept.






Oh, and where to connect the WOT PCV hose to the intake? Before or after the MAF? You want to do it after the MAF for a few reasons.
1) Absolutely no oil from blow-by should be allowed to contaminate the MAF element.
2) The air has already been metered so you don't want to double-meter it.


If you experience issues with the connection placed after the MAF, that is likely because you've removed one or more of your restrictors and your engine is now able to ingest a good bit of air quickly (the entire engine acts as a plenum in this case) before air even moves through the MAF causing it to register air flow.




Happy motoring!

Sorry for such the long quote everyone.

This is my first post and I am here because I found this information from fellow service members on Zeroyon. I am excited to have a clue where some of my problems are coming from and it seems it is the restrictors.

Now I see the picture on the inlet that shows the restrictor and I also have seen Ben's diagrams on sr20 forum. Now I am baffled cause I am trying to find the second restrictor he mentions in this post in the WOT section. I can not find any information on it in his diagrams or on the service manual, and yes I have the JAP 180sx service manual.

Here is a shot of the breakdown of that area. I want to know if there is a restrictor in there and if I can simply just add it into my line from the crankcase bleed.

[Motosx]

So just to make sure I understand. I have a s13 and if I go off the T on the valve cover on the turbo side to a catch can and then off the catch can to intake tube of the turbo this will relieve the pressure from the head/crank to stop blow by??? Is this the just of it.

[jamg]

great thread.

[cotbu]

Originally Posted by Motosx

So just to make sure I understand. I have a s13 and if I go off the T on the valve cover on the turbo side to a catch can and then off the catch can to intake tube of the turbo this will relieve the pressure from the head/crank to stop blow by??? Is this the just of it.

NO, All engine have blow by, under boost you create more, and that's for a normal healthy engine. The catch can, separates the oil from the air and keeps it in the can. On a excessive blow by engines, the catch can still separates the oil from air. This mod, alleviates the amount of oil being spit out. So instead of emptying the can twice a month, you may get 3 or 4 months of use before emptying. More cleaner intake systems, higher octane, looks like you really drive/care about your car.

[jr_ss]

Originally Posted by cotbu

NO, All engine have blow by, under boost you create more, and that's for a normal healthy engine. The catch can, separates the oil from the air and keeps it in the can. On a excessive blow by engines, the catch can still separates the oil from air. This mod, alleviates the amount of oil being spit out. So instead of emptying the can twice a month, you may get 3 or 4 months of use before emptying. More cleaner intake systems, higher octane, looks like you really drive/care about your car.

Essentially though, it does help your rings seal "tighter" to the walls, which creating a vacuum will do.

[Motosx]

Originally Posted by jr_ss

Essentially though, it does help your rings seal "tighter" to the walls, which creating a vacuum will do.

So then I do go from my catch can to my air intake then??

[jr_ss]

Originally Posted by Motosx

So then I do go from my catch can to my air intake then??

Yes, there are other ways to do it though.

Search this forum for catch can setups. You should find that there are a lot of threads pertaining to this setup and will answer your questions.

[ShadowMan]

I run it like this and have never had a problem. Still need to refine my tune but I think I'm around 300 whp or so, and this is my daily.



It's still obviously a work in progress as far as final routing of plumbing, but this catch can plumbing setup has been setup on the car for a few months now with no oil collection in the can.

[cotbu]

Originally Posted by jr_ss

Essentially though, it does help your rings seal "tighter" to the walls, which creating a vacuum will do.

I disagree. The oem configuration would by your description help the rings seal tighter. Pressure alone does that as you know, when the rings are worn they aren't getting better by this or the oem config. A side effect of running more boost will help seal the rings temporarily, but that's on another plain of thinking.

The negative pressure, allows the piston and rings to move freely reducing pinging, slapping and knock which can be heard and felt at idle speed with a misconfigured catch can setup. (Plugged, capped or no vacuum setup)
You could simply try this by capping off the hose that would be sucking the air out of the valve cover, try it! If your rings aren't sealing i suspect you'll hear and feel nothing!

So, i disagree that this or the oem routing helps seal the rings tighter, but allows them to perform better with less pressure to fight against. WOW! all most lost myself there, don't know if I'm a believer or not!

[Motosx]

this is how i've curentlly got it set up

[drift213]

I've been looking for this solution good thread

[Kingtal0n]

I Had an idea.

Somebody (not me!?) should install a very sensitive vacuum/pressure gauge on a PCV system from an OEM engine that is in good health. Preferably with a voltage output to be logged vs RPM/boost

Then, we can drive the car, and measure the "acceptable" conditions for the OEM engine...
And start to modify it, and measure the changes.

[fliprayzin240sx]

^^^That makes too much sense so it'll never happen...

[quickdiversion]

Originally Posted by Kingtal0n

I Had an idea.

Somebody (not me!?) should install a very sensitive vacuum/pressure gauge on a PCV system from an OEM engine that is in good health. Preferably with a voltage output to be logged vs RPM/boost

Then, we can drive the car, and measure the "acceptable" conditions for the OEM engine...
And start to modify it, and measure the changes.

This would be a terrific idea... expect almost no one has a perfectly stock setup. Even most "stock" sr20det's have the system messed with just cause the swap itself. So this would be very difficult. Unless we get some our overseas friends to do it.

[Almasxxx]

Up
Whats The Rotation for Black top (nvcs head) sr20det ??
and is it possible with picture

Thanks

[ForeignMuscle]

Does anyone know if the oil return tube is steel? The tube behind the exhaust manifold that the T on the valve cover originallywent to. I would like an AN fitting there rather than just clamping the hose on the tube. I can't findany info on. It looks like titanium..

[jr_ss]

Originally Posted by ForeignMuscle

Does anyone know if the oil return tube is steel? The tube behind the exhaust manifold that the T on the valve cover originallywent to. I would like an AN fitting there rather than just clamping the hose on the tube. I can't findany info on. It looks like titanium..

You're talking about the one on the block correct? If so, yes it is steel and I did the same thing. -10AN male welded to it for ease of connection.

[ForeignMuscle]

Thank you jr ss. Yes the one in the block but not the turbo drain. The one under the #4 exhaust port. If anyone is interested, I also found a place that sells a 1/2" male bspt to female 1/2" npt fitting for turbo drain. Makes it possible to use 1/2"npt -10 fitting, or any other size you prefer. I guess welding a fitting on would work just fine too.

[iRONDONkey]

i'm using the stock S13 valve cover set up.

so it should be like this-

the part of the 'T' that faces the firewall- has a hose that connects into the port on the motor block.

the part of the 'T' that sticks out towards the radiator- has a hose connected to the catch can.

the catch can has a hose that connects to the intake pipe, post MAF.

correct?

[cotbu]

Yes, Correct!

Originally Posted by iRONDONkey

i'm using the stock S13 valve cover set up.

so it should be like this-

the part of the 'T' that faces the firewall- has a hose that connects into the port on the motor block.

the part of the 'T' that sticks out towards the radiator- has a hose connected to the catch can.

the catch can has a hose that connects to the intake pipe, post MAF.

correct?

[ForeignMuscle]

Finished my valve cover recently. I'm excited to test it out. I will be routing to my exhaust with a Vibrant venturi eventually.

I went overboard with the drill. I think it will work fine. My goal is to not need a catch can, period.


Roll o' nickels


I used all -10 90* Earl's forged AN fittings. I wanted it all uniform.

[EsChassisLove]

Nice set up^

I m just gonna go S13.4, -10AN it, route it all through a GReddy can and call it a day. Lol.

[ForeignMuscle]

I love the 13.4 setup. But after the cost of the s14 valve cover and fabrication it was too much for me. I now have over 40 hours in mine after shaving, sanding, polishing, and welding I will never polish anything again as long as I live.

I have thought about doing the 13.4 on my own. Maybe create a jig so that it could be done correctly. I would be willing to do that if I had some interest from people willing to purchase the service.

[SrS13=MuchLove]

Ive been trying to figure out an oil catch setup for my sr s13 but im a little iffy on what i decided to do so i want yalls inputs/opinion on it. Other setup suggestions are welcome.

This is what i finnally decided on doing: t-fiitting on the VC that points frwd --> oil catch --> inlet on back of block. Thats the same inlet that the hose from the T (facing firewall) connects to. I would find some sort of atapter that allows both hoses to be connected there.

Im not even sure if that will even function right thats why i want to get some more experianced minds on it. The reason im doing this is because my intake/air filter doesnt have a MAF so im basically trying to find a place for the hose thats suppose to go there.
Another thing i want some more opinions on is the pcv. The previous owner had it closed off with a rubber cap, will that be fine or should i reconnect it, maybe put a breather on it, idk?

Ive thought welding a fitting to my air filter but thats plan B, if yall tell me my current routing wont work. Any help will be greatly appreciated. Thanks.