Hi AlanG,

Thank you very much for the pics

I assume the black valve under the crank case breather tube is the PCV tube ?

So these three tubes just point down towards the road and have no filters on the end, basically just a hallow tube ?

What about the other side, the plave where thsse tubes where connected to, what do you do with that side ?

Any special size tubes to be used ?

Cheers,
Ray

 

The "black valve" is just an open connector. The PCV valve is at the inlet manifold area on '99 cars, don't know about earlier ones.

As Andy recommends, run the crankcase breather and each of the rocker cover hoses to the road.

I used 1/2" piping.

I put mine to a tank. The two rocker cover hoses went to a "T" before going to the top of the tank and the crankcase breather went to the original fitting on the tank (again near the top of the tank)

 

Just to add to Alans note, if you use a tank, ensure that you also have a decent size vent exit pipe on the tank !
If you just have a single small vent then you can still build up crankcase pressure and end up with oil leaks and oil consumption.

Andy

 

Hi,

Thanks all.

What do you do to the places where the lines that are now pointing down to the road used to connect to ? Just plug them ?

Cheers,
Ray

 

Yes

 

ok thx

 

What do you use to plug them?

 

Alan what is all the extra pipework valve and sensor for ?

If you don't mind me asking.

 

Huxley

That was AndyF's car when he had the chargecooler (intercooler welded up and water running through it )

The pipework is his fuel lines going to a T piece and then to his rails as part of a prallel rail mod. The sensor on the manifold i think was used either for an additional fuel injector (boost related) or pressure sensor for water injection, though don't think Andy had water injection.

 

I did have water injection on it at that time as I was running the std ECU and was trying to keep it from detting at 1.8 bar

Andy

 

"was trying to keep it from detting at 1.8 bar "

In first gear.....

 

Water injection system...but for sure not injecting water

 

Next best thing to a 'sticky'

 

Just to update - I still only run the crank vent through the catch can. I need to empty it every 6 months or so, and keeping the heads with normal pipework has lead to no problems with misting in my TMIC.

Richard

 

Wish I had known that 12 months ago...
Graham.

 

I've been watching this thread off and on for a while so once and for all, help me get this straight in my head:

There are no downsides to rerouting the oil venting/PCV system?

The way to do it is basically find the three vents (crankcase and the two rocker covers), unplug them from the induction pipe (if their pipes end up there), plug the holes in that pipe, then stick a long pipe on each of the vents and run them down to the underside of the car near the ARB, unfiltered. Alternatively plug them into a catch can? Is there no need for breather filters on the ends of the three pipes or alternatively on the catch can exit vent?

What happens with the PCV valve under the throttle body? What does that connect to originally and does it still need to connect.

BTW it's an MY98 WRX, used as a daily driver but always gets a good workout. Last thing is I can't seem to get the links that show where the three vents actually are. Help!

 

Nick, you are right. I have gone the catch tank route as I compete with the car.
Over this year, 3000 road miles and 11 hill climb weekends there is no oil in the TMIC, no oil in the throttle body, and no oil in the catch tank.

The catch tank vent to atmosphere via a 15mm tube ties off on the front lower wishbone ALK mounting.

The motorsport reason for the tank is if the car crashes/turns over any oil spill from the engine vents into the 1 litre tank.

Graham.

 

Been thinking about this, does the manifold not suck in unmetered air via the PCV from the catch tank exit or open ended pipes (if vented to atmos) when not on boost, ie vacuum?!

 

iirc:

The valve from the engine block to the manifold is one way, that is: it free flows from engine to manifold..at a pressure.
With the engine block effectivly vented to atmosphere freely, ie down a 15mm pipe the engine 'air' will flow out of the block via the least line of resistance. The pressure to pass the one way valve is far greater than the pressure of the 15mm pipe, so it passes down the pipe (and in my case into the catch tank.
Somewhere in my monster Project thread there is a sketch of the whole system modified (about page 11 I think)which I followed (with a good result as stated.)

Graham.

 

As i see it the valve will be open (doesnt take much at all to open) when the engine is in vacuum helping to suck the contaminated air from the crankcase breather, when this is the case i would imagine it will also suck air in through the pipe that is vented to atmos via catch tank? The path of least resistance will be into the manifold as it will be under vacuum?

OK when the pipe (the vent to atmos one) is fed back to inlet pipe after the MAF.


The valve is only closed on positive manifold pressure and this is where the catch tank will be doing its job.

 

Spot on John, under idle conditions or below 0 manifold pressure the crankcase gases will be drawn into the manifold, as well as possible air from the catch can if VTA, which is why IMHO they should have a filter on them.

 

Thought so Jim Deffo worth adding a filter IMO too.

I suppose the unmetered air (not a problem on our ECU's) wont cause a problem as when the manifold is in a vacuum state the engine isnt being pushed.

 

I would add that my catch tank is full of steel wool to help condense the oil in the 'air' in the tank. Acts as a crude 'scrubber' in the instances you talk of.
Graham.

 

Ah yes, I was thinking of what to use inside my old catch tank (possibly fish tank filter foam), but that was a much simpler system on my Clio 16v - just a breather pipe off the cam cover that normally plumbed in between the air filter and throttle body, so when I turbocharged it, I rejigged it to go to a simple catch tank with a breather filtered outlet. Sometimes I'd get oil vented out so the next stage was to try and keep the oil in the tank with some kind of foam / steel wool inside it. I'll remember that, it's a good idea.

So now all I need to do then is find a catch tank with three inputs and one big output. What diameter are the three breather outlets on the engine?

 

iirc: 10mm OD.
I found the pipe for mine from an aquatic centre, the T's too and the tank from Halfords..cycle dept!
Whole job cost about £5 and ages to do it!

Testemony: It is all still there and has worked a treat.
Cheapest thing I have EVER modified on any car

Graham

 

LOL quality, looks like I'm off to the tropical fish centre then. Remind me what to do with the PCV valve (is this the thing in the underneath of the throttle body?)

 

You do nothing with it. Leave it connected to the engine block using the same formed pipe.
Graham

 

Ah good, so am I right in thinking that that PCV valve does its own thing, drawing air through the crankcase directly into the inlet manifold under vacuum? And with the three breather pipes redirected to a catch can, under boost that PCV connection simply shuts tight and all the oil vapours that would normally be pushed through into the induction tract just go through the catch can?

 

Yes!
Realy does work and keeps the octane rating 'clean' so the mapper can push that little bit harder...with confidence!
Graham.

 

Cool. That's my weekend mission then, along with trying my ARB on the stiffest setting for a laugh. Cheers for all the help.