Jump to content
SAU Community

Oil - Air seperators; what sort of gains?

Cool Hand Luke
 Share

Recommended Posts

Busky2k Veteran

Busky2k

Posted
Posted

I wouldnt think there would be a direct performance gain. The main reason you use it is so you dont get oil shitting up your intake/intercooler. Also the oil can contribute detonation on cars with alot of blowby, but i wouldnt go advancing the timing or anything like that after I installed a OAS.

CMS Drifter Experienced

CMS Drifter

Posted
Posted

Correction to all.

An oil/air separator simply allows your engine crankcase to "breathe" and separate oil from air before returning it to the intake.

With the parts moving inside the engine (pistons up and down) there can be a marginal amount of air displacement.

This air has to come and go from somewhere.... in standard form, there is a provision made, but can feed oily air back in to the intake.

By fitting an oil/air separator, it allows the oil to be removed from the air before returning back to the intake.

It also reduces crankcase compression that is caused by the displacement of air and blowby caused by worn pistons/rings

JimX Grand Master

JimX

Posted
Posted

The oil/air separator doesn't allow the crankcase to "breathe", it's the holes in the cam covers which do that. Whether you have them feed straight back into the intake or plenum or through a catch can or separator or even just a breather filter is irrelevant, in all cases it still "breathes".

Busky2k's description sums up the oil/air separator's function perfectly, there is no need for a "correction".

J.B.E Apprentice

J.B.E

Posted
Posted
Originally posted by Busky2k

I wouldnt think there would be a direct performance gain. The main reason you use it is so you dont get oil shitting up your intake/intercooler. Also the oil can contribute detonation on cars with alot of blowby, but i wouldnt go advancing the timing or anything like that after I installed a OAS.

Busky2k is sorta right, the reason for installing a oil air seperator especially on race or high boost application cars is cause the oil that ends up being recycled back into the engine goes down and gets burnt with the gas, with it mixing with your gas it lowers the octain rating which causes detonation. so by installing 1 of these you will lessen the chance of detonation and run safer higher boost levels especially if you do hav blow by problems. So the only performance gains i could see would be very minimal.

rbs13 Community Regular

rbs13

Posted
Posted

instead of having the cam cover hose going to the plenum make it go to the oil catch can and on the other cam cover the one going to the intake just make that go to the oil catch can as well.. theres that way or.. leave the one in the plenum and make the intake hose go to the catch can instead.. if ya know what i mean??

J.B.E Apprentice

J.B.E

Posted
Posted

I personaly dont see the point in havinin a oil air seperator if your only goint to run 1 of your hoses from your valve covers to the catch can, but yes VLRB20DET you just disconnect them from the plenum and the intake ducting and run them to your catch can, dont forget to plug the hole up that you've disconnected. Because on most R32 series valves covers the the connections are pointing in two different directions you could take them out and use the connections from a RB20DE which are just right angled connection and dont have the connector piece going between them you can point them in any direction you want, eg: to you catch can where ever you decide to put it.

Hope that helped

Soon as i get sum pictures from my camera to the comp i'll show you how i have mine.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • sunsetR33
      Replacing turbo water line - any recommendations or advice?

      By sunsetR33 · Posted

      One thing I can tell you is, do it properly the first time. If you encounter unexpected problems just let the car sit for a week or two if you have to get some other parts or figure stuff out.  I'd have said go and use as many OEM parts as possible but since you want to change the turbo later on a custom kit is probably the better choice. Since I have no experience with RB25 just compare parts diagrams and images before buying a line kit and it should be easy to see if it has everything you need. Amayama has very good parts diagrams and part number lists, that is what I used a bunch to figure out what I might need. And don't forget to plan ahead and possibly renew other stuff that's easy to get to while you're in there doing the turbo lines. Happy wrenching
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 4:   Hi all, good news. Engine is running and all the gaskets and seals seem to be working as intended. No leaks so far, even the JB Weld seems to hold. I flushed out the old coolant a few times and put in fresh coolant, not Nissan stuff, I decided to try the Ravenol Protect FL22, they claim it works for a wide variety of JDM cars and the opinions on it by some people were pretty good. And it has the nice poison green color! And man am I glad I bought a coolant system tester earlier this year, vacuum filling works wonders on this engine. I can definitely recommend this to anyone still doing it the old school way. All you need is compressed air supply. Will have to do a small test drive as soon as I can, I removed the gauge cluster again as the tacho needle was still bouncing around a bit but it was much better than before already.  I also found some cracks on all 4 tires inner and outer sidewalls. Apparently these tires should 't be parked on for extended periods or be kept under 0 degrees during storage, which I did not know. Clearly the previous owner didn't look into those details either, he probably bought them just cause they are cool semi-slicks. I'm just wondering how tf I am supposed to reach 30-80 degree tire temperatures on the public road consistenly, these tires were never going to work for my use case. I'll probably order Continental SportContact7 ones as these are the best allround summer tire available right now and I don't think I'll need anything crazier for now. Do let me know if you have experience with various tires and which ones you recommend.
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      You have no idea how many goddamn boxes I received these past three months haha Most have been put to use by now though, luckily
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Not going to pretend I didn't do a bit of junky work this time around, but mostly due to the fact that some things I am not willing to spend days fixing right now, like wiring. I try to do most things properly the first time around.
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Regardless of neglect or incompetence, fixing either is tedious and annoying. Most of the neglect on my car is definitely rust. I hope I can at least pass inspections later on and they won't fail the car due to slightly corroded hardlines. I was generous with rust converter and wax and it looks ok, most lines in the rear are hard to see properly anyways.  Definitely will test them though to make sure they don't rupture under pressure, in that case the car isn't going anywhere this year.
×
×
  • Create New...