The catch can conundrum on Blue Wasabi V3.0

[FozzieDriver]

As some of you know, I am in the process of rebuilding Blue Wasabi yet again.
Feb was my last build due to a failed fuel pump and running lean on cylinder three. So I elected to pull everything off the car and rebuild bearings and Weseco 100mm pistons.

Two weeks ago I went to RedStar Raceway and was wearing some semi slicks. At the end of the long back straight my bearings ran and number 4 spun. I have been very confused how this happened and have been making up various hypotheses. One of which was oil starvation due to high G forces.

You can see the last corner at around 07:40 and at the end of the straight the bearing lets go.

BUT, I took my catch can apart to clean it and found it full, and I mean full of beach sand.

In December last year I went to the coast and did a bit of dune driving. And 1000km of dirt driving. My catch can vents to atmosphere under my front cross member behind the front wheel.  My Theory?
December last year sand got sucked into the catch can under vacuum. Collected in the can.
Oil pump could handle a bit of sand and the filter would take care of the rest. Most of the sand would have sat in the catch can.
September this year. A vigorous drive with a lot of boost and vacuum with some blow by and hot oil and the sand is dislodged in the catch can and ends up in the oil pump. There it impedes the pressure relief valve and the valve is stuck open. When I hit the end of the main straight and geared down to 4th, the pump could not keep oil pressure as the valve is now open and number 4 ran, and subsequently spun.  The rest of the bearings followed suite when I drove the car round to the pit exit to get off the track.
So there are a number of different options for catch can installation and in my mind one should really have two, keeping the heads separate from the crank. Also, venting to atmosphere seems pretty daft in hind site, especially considering the Forester does spend quite a bit of time in a dirty environment off road. And it is probably not good for the polar bears.

So now I face another R25k rebuild because of an incorrectly installed catch can.
All comments are welcome as I have to see this as learning curve for all of us.
Donations are also welcome

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[sav]

That is extremely unfortunate.

As mentioned before, an oil catch can is simply an inline filter so I cannot understand why the muricans and everybody else is trying to over complicate it so much. You've got gases/vapor containing oil, cool - filter it out and catch it. Done. Nothing fancy or complicate about that.

Here is how mine is connected and it WORKS:

Stock plumbing, PCV in place, nothing is different from stock and it's still a closed system. Only difference is that the all the vapor coming out of the crank case is getting filtered.

I've got a tube with a ball-bearing tap connected at the bottom of the OCC for easy drainage.

You could add a 2nd one for the heads breather pipes but for my application it would be overkill since I've had it hooked up there first and it's caught barely anything at all.

[Stev0]

Thats not a lekker feeling.


Hope WASAAABee comes back stronger than ever!

[FozzieDriver]

Blue Wasabi is back on the road. Albeit at .5 bar boost.
And less than 4000 rpm.

Now my air con does not work[emoji35]


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[thebus]

Do you have pics of where your oil catch can is connected?
All the pipes look confusing and not sure if its 3 pipes or 4 that need to be connected.

[sav]

2 Pipes per catch can. I don't have pics unfortunately, but think of it as an inline filter.

[FozzieDriver]

I put an inline catch can setup back on my car. Basically using the catch can as an oil/air separator.
So two pipes from the crank breather to catch can and catch can to turbo inlet pipe.


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[thebus]

Hold on just a rooting tooting minute...I saw that pipe yesterday and it was bunged off.
Will try check tonight but if its blanked off, is that bad?

[sav]

Hold on just a rooting tooting minute...I saw that pipe yesterday and it was bunged off.
Will try check tonight but if its blanked off, is that bad?

The one on the crank case? Yep, that would be bad.

[FozzieDriver]

Not good. Where does your positive crank case pressure go?
Is the one on the turbo inlet pipe also bunged off?


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[thebus]

I will look asap. My memory thinks its the one on the PCV Valve. So where is the other end?

[FozzieDriver]

On the turbo inlet pipe. Probably under the intake manifold

[thebus]

red circle is turbo

[FozzieDriver]

OK, so if you follow the pipe from the Blow Off Valve on the Intercooler, it will take you to the Turbo Inlet Pipe. It joins on the side. Above this join is a pipe that should go to the block and is a breather pipe.
It is a bit different in my car as I removed most of that system ages ago.
The turbo inlet pipe actually has a multitude of hoses that join it. Sounds like you may have had a catch can installed at some point.