oil breather exhaust vent system
 

Well, ive searched the archives and there are some pretty good articles on all this oil breather..venting..separating stuff.
https://rennlist.com/forums/showthre...light=air+pump


This is what im thinking.
https://members.rennlist.com/v1uhoh/crankventidea2.JPG

using these ideas

https://members.rennlist.com/v1uhoh/oilssepv3.JPG
http://members.rennlist.com/v1uhoh/oilbreather0001.JPG
https://members.rennlist.com/v1uhoh/LOoilbreather.JPG

And my own catch can from 3.5 “ dia tubing an 1 inch fittings vented to the exhaust back near the muffler (ala Porkens idea..bottom image)
http://members.rennlist.com/porken/CrankVentTube.jpg

Anyway...
I started to install the pulley for my SC today then in my usual fashion i now have the timing belt covers off, airpump off, alternator off and power steering pump off . All of which aren't required for the install i might add. :roflmao: :banghead: I have a problem :roflmao: Now im cleaning stuff AGAIN! Its none stop i tell ya. Now im having the Tbelt covers refinished. This is such a tall slippery slope Im on!

Of course now with the airpump off, im thinking of a vac pump in its place...thoughts..ideas??

I can add the drain to the oil pan later, but its all in easy view and acces for me now. My oil pan has the spare access cover at the front which is nice.
:cheers:

Help I am falling and I can't get up !

I'd be careful with the drain back. My catch can picks up a lot of moisture from the blow-by. The separator has to be carefully tuned to get just oil and not water. The fluid in my catch tank is often 2 or 3 times the oil loss. Especially true for street cruising.

Dang Tony that is very cool stuff. I will of course want to go there too. Is the filler insert your design? About pot scrubbers .... have you used them to scrub pots? IIRC they leave tiny curls everywhere sometimes .... not too good.

http://www.republicsales.com/MANN/Provent_Brochure.pdf

Its in PDF format but its pretty cool and well made. .98 inch inlet/outlet..an inch for all purposes.

what does 52.8gal/min correspond to in a cfm flow rate...ive tried my math but i think im missing somehting?
http://members.rennlist.com/v1uhoh/ProVent2.JPG


:cheers:

The nastiest feature of the 928's engine is the breather system! I run mine through an aircraft air/oil seperator and then dump the waste....all of it, back to the turbo's oil scavenging system. The "cleaned" air then feeds into the airbox after the filter. In theory if the oil is hot enough you drive out all of the condensation you pump back down the drain. Having the oil scavenging system helps here because the oil off the turbos is quite hot! I have another vent tube that runs back to the airbox for any water vapor that comes back up from the turbo oil drain catch can.

A boosted 928 can lift massive amounts of oil, so much you swear there is a bottom end problem with the motor. It is the nature of these cars and has to be dealt with. With 21 psig of boost in my S4 Audi I have zero problems with it lifting oil...go figure.

My cousin is a Volvo mechanic and he tells me there is a pinhole designed into their intercoolers to allow for blow-by oil to drain out the car...seems to make sense, a hole small enough to not be noticed by the ECU, yet big enough to allow the wasted oil to drain. Different method, but probably effective. Aircraft typically vent to atmosphere and can blow off a lot of oil in short order...has something to do with the high duty cycle of aircraft...running 80% all day, where your car runs 10% all day and 80-100% for short bursts only.

I'm interested to see how well this works out. I think the aircraft unit is like $165.00 or so, so it is not cheap by any means.

Throw some dirt on that engine!!!!

:roflmao:
yeah right! thhe clean one is the one on the stand. Im now in the middle of cleaning all the crap off the one in my car. 147K miles and its ugly!! The top half is done but the bottom is tough. Its celaner but not a clean as i would like it now. It will do though.
Anyway, a big fan, lots of parts cleaner, goggles, a jump suit and gloves. Looks like im cleaning up toxic waste or somehting!
:cheers:

yeah they really will if the breather tube on the belly is iced over or plugged!
The avaiation ones arent cheap, thats for sure. Has to do with the FAA ..PMA stamp of approval etc etc.

:cheers:

Just a thought - those looked like soldered joints on copper piping where you vent hits the exhaust. I fear the solder will soften under heat and load. Also - that nipple that goes into the collector - make sure the end of it goes IN to the main area of air flow - not just to the sidewall of the exhaust, but past that into the airstream.

Quick Carl,

That's an old pic, below is basically what I'm running now, except with all rubber tubing.

https://members.rennlist.com/porken/...tCrankEvac.jpg

Note: the pilot tube extends into the exhaust stream about 1", at a 45 degree angle.

That set up works well for you PK? no smoke..smell etc etc. Ill be venting off both valve covers.

I need to do some more reading and ask a few questions, but i NEVER see this issue raised with the Ford Cobra crowd. what do they do? My guess is they chuck it back into the intake prior to the SC with out any issues. Any ideas?
:cheers:

Hey tony, great progress, and like the powder coated bits are using? If you do a search, i posten to one of kens pcv exhuast threads, with a link to an audi 20v turbo discussion. I think it may have some good ideas in it, as it relates very closely to your setup: multivalve boosted application.
Hans

Go to the last post on this thread:

https://rennlist.com/forums/showthre...41#post1347441

Thanks Carl, seems im getting myself on the right track in designing one, thanks to the input and the list. The more separation you can do up stream of your actual catch can, the better. Thats why i made something similar to the setup Prof Ott made for his stroker(blue item pictured previously) . Its sits direcly where the oil filler neck is on the S4...which is right above the swinging crank. Im messing around with the idea of making some very simple and small separators to go on/in the valve covers. There is one already but it is a simple inverted " cylinder" of sorts. Im thinking of adding some sort of filter element to it...and another cylinder type spearator on the other opening of the valve cover. These 2 will be joined to the one at the filler neck...which will go to the catch can like in my schematic shown earlier.

:cheers: