Crankcase ventilation - let's talk upgrades

[Volvo5.0]

4 hours ago, Boxman said:

 @Volvo5.0 what's your reason for putting a second vacuum line closer to the box? Just more idle venting capacity? Have you done anything to relieve the additional crankcase pressure under boost?

The P2 cars have the vac. line close to the box, so I figured since I was making the PCV pipe from copper tubing anyway, why not add one there. I doubt it's an upgrade, but I do feel like the one-way valves make a lot of sense if you think about it.

 

4 hours ago, Boxman said:

 and also think the vacuum draw of your boosting turbo at the intake will be stronger than the vacuum the Venturi effect provides at the orifice

Trying to understand what you mean by this. Where is the vacuum draw at the intake when the turbo is boosting?

[Stefan Mohammed]

1 minute ago, Volvo5.0 said:

The P2 cars have the vac. line close to the box, so I figured since I was making the PCV pipe from copper tubing anyway, why not add one there. I doubt it's an upgrade, but I do feel like the one-way valves make a lot of sense if you think about it.

 

Trying to understand what you mean by this. Where is the vacuum draw at the intake when the turbo is boosting?

 

I think he means that the turbo spooled up creates a stronger vacuum draw in the turbo air inlet pipe as compared to the vacuum draw produced via the Venturi effect from having a small PTC opening. 

[Volvo5.0]

1 minute ago, Stefan Mohammed said:

I think he means that the turbo spooled up creates a stronger vacuum draw in the turbo air inlet pipe as compared to the vacuum draw produced via the Venturi effect from having a small PTC opening. 

Thanks for the explanation. That makes sense. I was trying to picture what part of the intake (manifold) could have vacuum when in boost.

[wizzard_al]

The PTC is to keep the vapor from freezing in the hose, and I'd guess Volvo tested it and felt it was the right size for stock engines. Seems to be the same one on all cars with 5 cylinder, up to at least '05. 

[project_850]

I use one of those baffled/vented oil caps from the older Volvo B20 motors and have that hooked up to a Moroso catch can vented to atmosphere.

I'm also a believer in having a vacuum draw on the crankcase so I have the stock PCV system hooked up with one of these oil separators in line before the PTC. Charge pipes are clean as a whistle.

 

No problems @ 20psi with a 20T with meth injection :)

[venderbroeck]

That's a jegs seperator right?
Those seem to be pretty good. How long does it take before it's filled up?

[project_850]

It is. I empty out every oil change. Gets to about 1/4 full every 5000km.

[lookforjoe]

The problem with the Jegs is the I/O is really too small. If you go bigger turbo or over stock rev limit, that wont work at all.

Most has been covered in previous posts. I would agree that it has been proven for Volvo applications the cam vents used in many other setups doesn't work for us. Unless you build a drain back system, you will push oil out the motor so fast it will be empty after a few short pulls. Higher rpms, faster it leaves.

Any mods should be kept as simple and serviceable as possible. Volvo sells 14mm ID line used for breather system by the meter 949701 - I used that where possible, as it's longevity is documented.

99 - PTC has a (much) larger orifice, you can use that & move the vac draw elsewhere.