fast951

Open up the hole in the AOS.

Turbo mount is vented and helps drain the oil from the turbo. You don't want to add any pressure to negate it.

ehall

I did it with two of them. The seal is just as good
as original, unless you mangle the top.

ehall

Increasing diameter increases flow, but reduces pressure. Restrictions create pressure.

KSira

Speed will also decrease, letting more of the oil separate from the air and run back to the engine, provided that the hose is higher than the outlet obviously.

Thom

This is what I said but looking at the equation another way.

Teddy952

What effect would connecting the turbo mount vent directly to a vacuum source instead of the side port on the AOS have? If that is just a vent, no liquid oil, then connecting it to the intake manifold with a check valve inline will assist with draining the oil through the turbo....?

ehall

Well, flow and restriction only work one way, but okay.

Tom M'Guinn

Thanks, I hear you. The approach I have in mind would only decrease pressure in mount/drain -- never increase it. The extra line would have a check valve, so the pressure in the drain/mount would be identical to stock unless/until the crankcase has positive pressure. When the crankcase has positive pressure, the check valve will open and reduce the pressure in the crankcase (and therefore the pressure in the turbo mount/drain). Or am I missing something?

Thom

If the pipe between the turbo mount and the AOS is a "drain" pipe, then we want vacuum in it. By the time some check valve added in the system opens it means there will be pressure in the system whereas we only want vacuum.

Voith

My seal was in good condition too, but it is very brittle. I took it out and it broke.

Looks like it is made of buna rubber that doesn't like synthetic oils.

Very simple seal so replacement should not be a problem.

bebbetufs

I too have considered this many times but I have one big concern. We know from the 928 that the crank can push oil up through the return chutes and load up the heads. This can supposedly cause problems by leaving too little in the sump. The 944 8V has positive pressure in the cam tower (thus the relatively common problem of blowing out cam tower gaskets). This could help push the oil back to the sump. Could not relieving this pressure cause problems, and possbly flood the catch can and/ or the intake?

On the other hand it could alleviate the problem with the cam tower gaskets.

Teddy952

This is the fitting I used in place of the cam plugs.

http://www.summitracing.com/parts/fra-460618

URG8RB8

Thanks for the link Ted, nice and simple adaptor! I assume you are venting your cam tower all ready since you are using this fitting. Have you experienced any of the issues mentioned above? How much oil blow by is coming from the cam tower. I would assume not that much, but you know what that gets you. Which check valve did you select for this line?

marcoturbo

Doesn't this adapter hit the cam cover casting (where the Porsche script is)?

I've bought this kind of M18x1.5 adapter to fit my pcv and couldn't screw it full...

Teddy952

Initially I used the cam tower port as a source to monitor crankcase pressure/vacuum. I then tried connecting the cam port to one of the smaller intake vacuum ports with a check valve inline. I wanted to introduce vacuum to the crank case and the check valve would block the boost from entering. The test was very short lived.... after a quick drive I noticed a very little amount of blueish exhaust smoke. I believe the intake was pulling too much oily vapors from the cam tower port or maybe it sucked up some oil. At the moment I'm not using any of the cam ports for venting blow by. I would like to eventually but I haven't found a decent solution.

Here is where I got my check valves from.
http://www.usplastic.com/catalog/def...arentcatid=870

I used brass because once I found a solution I was going to use copper tubing with some compression fitting to make a custom venting system. Some of the brass valves have a 1/3 PSI cracking pressure. Maybe using a couple cam ports with these low PSI cracking valves will work? I don't think the cam ports are a good source for pulling vacuum on the crankcase, they maybe better at relieving pressure though. Once the crankcase pressure got over 1 PSI these valves should pop open and flow out cam tower port and into a catch can. I'm concerned about what will flow out of the ports though. I would assume oily vapors but I don't know for sure.