Oil Blow Back into my Turbo..........

[aaronng]

And would this not then push air through the engine and out from rocker cover to intake to turbo? This will then explain his oil in the intake to turbo. Sorry don't know how the system works on these motors.

Nope, the air goes into the crankcase, out through the PCV valve and into the intake manifold (which is after the turbo). The rocker cover is the inlet and the PCV valve is the outlet.

[JasonGilholme]

is there a mix up between the head and the valve cover here???

on my engine PCV air enteres via the valve cover, not the head...

[fatboyz39]

vent it all to a catch can SIMPLE....but question is, why are you getting so much blow by after a rebuilt motor? Piston rings not sealing properly?

[aaronng]

is there a mix up between the head and the valve cover here???

on my engine PCV air enteres via the valve cover, not the head...

I made a typo. I meant valve cover, not head.

[DLO01]

Nope, the air goes into the crankcase, out through the PCV valve and into the intake manifold (which is after the turbo). The rocker cover is the inlet and the PCV valve is the outlet.

So whats the one going to the intake arm (before TB) in the photo?

[Lukezen27]

vent it all to a catch can SIMPLE....but question is, why are you getting so much blow by after a rebuilt motor? Piston rings not sealing properly?

Hey Jimmy

Oh might have been there since my HG blow?

Never checked beforehand so I'll clean it out and see if it doesn't come back!!

[beeza]

It's the most confusing thing about a car is the PCV valve...

hehehe,I needed to put system on the end of that but how true is it

[Limbo]

Luke look at the PCV on this site. It tells you how to plumb it for a turbo setup.

http://www.beesandgoats.com/boostfaq/g2icturbo.html#PCV

[Weq]

Ok im going to try and help you, explain the situation.

You are getting blowby. Excesive blow-by is bad and is caused by your ringlands going crack. What u have described sounds pretty normal, espically for a car that was NA. The PVC breather on the valve cover is a two way valve. Ive see some shops put a one way valve here, this is incorrect.

The function of this outlet is to help evacuate any pressure that builds up in the motor. If u put ur hand over the valve, u will feel it genlty push out air at idle and under more pressure once load is applied to the engine. Once again, all normal. Plumbing hte valve into the intake under a negitive pressure will allow the motor to pull out the gas, and keep it healthy. Irregular situations will result in smoke being puffed out or excessive oil splatter being expelled. it is the natur eof the beast that oil/fuel vapour will be mixed in with this air, which can build up in the intake system if. Usually the engine burns this off, or it clogs up the throttle body and intake manifold.

What you can do;
You have a turbo setup, so u will get a little more blowby then most. What u are experiencing is normal. The oil buildup wont really do all that much other then cause a degrade in performance over the long term. You options are;

1. Catch can. Plumb a catch can in between the inlet and rocker cover. Note that venting this gas in anyway is illegal. Catch cans come in inline configurations with and without breathers, and with and without baffles. If u have a breather less catch can, you want to have a baffle or stuff it with metal wool. this will help catch any oil vapour that is in the air, and stop it from building up in the intake. This is also the ideal solution, as it allows the engine suck oil vapour out of the case, which aids in crank case pressure buildup, but does not contaminate the intake tract because it is caught in the can.

2. Run a breather filter. This is illegal. But it works. Its an acceptable solution for a midly modified motor at lower boost levels. Even at higher boost levels, its still acceptable. Its not ideal, but allowing the motor to vent any pressure it needs is the main feature of this breather. Pulling out out of the motor helps, but its been proven to be relible without it.

Personally, on my car, for half the time i ran stock setup (rocker vent plumbed into the intake pipe causeing oil buildup) and it didnt really bother me gunking up the turbo. These motors have alot less blowby then a nissans, and turbos are designed to take this kind of usage.

After i cracked some ringlands, i used to let the breather and all the blowby just drain under the car. When i put my new motor/s in, i used a breather filter. Because i started to run more boost and differnt ring gaps. Plumbing this oil vapour into the intake will reduce octane rating and can induce pinging under excessive load.

[Weq]

Nope, the air goes into the crankcase, out through the PCV valve and into the intake manifold (which is after the turbo). The rocker cover is the inlet and the PCV valve is the outlet.

Its a two way valve. Actually its not a valve at all, its just a hole. Under certain loads it will expell pressure, under other loads it will suck in air. Plubming this isnto the intake system, it mostly expells air because the negative pressure of the engine overcomes it.

Checkout the massive threads on honda-tech regarding adding more vent ports and catch can setups... Its not something trivial, everyone has there own opinions and theorys. There are a few acceptable practices when it comes to PVC.

[beeza]

Thanks Weq! Great work! Repped!

So that's the thing,there's no 1 answer,there's a number of possible things you can do,ya just gotta understand and choose the best one for your set-up.

[aaronng]

Its a two way valve. Actually its not a valve at all, its just a hole. Under certain loads it will expell pressure, under other loads it will suck in air. Plubming this isnto the intake system, it mostly expells air because the negative pressure of the engine overcomes it.

Checkout the massive threads on honda-tech regarding adding more vent ports and catch can setups... Its not something trivial, everyone has there own opinions and theorys. There are a few acceptable practices when it comes to PVC.

From my understanding, the PCV is a 1 way valve.