Need som advise on crankcase ventilation...

[S2SE]

Hey!
I've just built a 2.5l engine on a diesel block. And crankcase ventilation was kinda forgotten when I put the whole thing together so I made a temporary solution wich turned out to be not so good (or is it?). Im using the AAN valvecover and only using the rear connection on it. And then I use the oil return from the turbo on the diesel block as ventilation in the block (as shown in pics).

Now what Im wondering is do I have to have ventilation on the block, and if so, is the best alternative to fit the original one from the 3B/AAN on the back of the block under the intake manifold or is the one on the valvecover enough?

I have gotten a quite big amount of oil in the one from the block but mostly condensation in the bottle at the valvecover

http://www.garaget.org/mypage/gallery_image.php?user=14004&image=2030991

http://www.garaget.org/mypage/gallery_image.php?user=14004&image=2030994

Regards,
Tomas

[diesel des]

Interested in this too as I'm building the same. I was going to drill the pipe in the cam cover and take ventilation from there through a catch can cyclone with drain to the sump and vent to atmosphere or back to turbo inlet. Hank in the states seems to only use ventilation from the head and none from the block.

Sent from my GT-N7105 using Tapatalk 2

[S2SE]

Hi!
I forgot to write that I have drilled a couple of holes in the pipe that goes in the valvcover too! think it was 2.5 or 3mm holes!

[Rusty]

So are you no longer using the turbo oil return?

I assume you have blanked off the other end of the pipe that originally went to the inlet hose?

a couple of 3mm holes is nowhere near enough. I'd be looking to drill all along the top of that 22mm hose with 8-10mm holes.

You need to run the 2 lines to a sump return swirl pot, to remove as much oil as possible, then you a properly baffled catch tank and finally, have a return line to the inlet pipe, to create a small vacuum under load and stop the breather creating a nasty smell.

[S2SE]

Im using the original oil return for the turbo that goes in the oilpan, had a 3B engine from the beginning. Now Im using the diesel engine oil return as a ventilation hole.

So you think I should make those holes larger?

I was thinking maybe something like this:


But instead of using the old oil return I will use the original one under the intake manifold that has some kind of a oiltrap in it.

[Rusty]

You need to add a vent to the tank and as I said above, I would recommend running the two breathers to a swirl pot and then the outlet of the swirl pot to a catch tank and then the outlet of that to the turbo inlet or the DP.

Check out this thread from page 4 onwards.

http://www.s2forum.com/forum/showthread.php?t=47719&highlight=k24r+catch&page=4

[UrS4boy]

Hey! I've just built a 2.5l engine on a diesel block. And crankcase ventilation was kinda forgotten when I put the whole thing together so I made a temporary solution wich turned out to be not so good (or is it?). Im using the AAN valvecover and only using the rear connection on it. And then I use the oil return from the turbo on the diesel block as ventilation in the block (as shown in pics). ....Regards, Tomas

Why can't you just reproduce the OE AAN crankcase ventilation system?

http://forums.quattroworld.com/s4s6/msgs/22506.phtml

[diesel des]

The stock aan system is crap when you start making power or drive hard. Under high g acceleration or cornering oil comes out of the block breather as its low down at the back of the engine. This overwhelmes the system and you get oil in your intake. This is why it seems better to do your ventilation at the head. Less oil up there to start with.

Sent from my GT-N7105 using Tapatalk 2

[Rusty]

You can, its just more complex and expensive. You could combine to 2 and replace the OE function but you're looking at £500 vs £300.

[S2SE]

Solved it by putting back the original one under the intake manifold, got just a little bit of oil in the bottle I have there after som hard driving...

Also got the car fully mapped with a result of 716hp 759nm. So now I need a new rear diff and a driveshaft so if you guys know someone who has this plz let me know =)

[diesel des]

Interesting. So your still taking ventilation from the head with the holes in the can cover pipe plus the one in the block under the manifold and draining back to the sump from a catch can? Did you try just taking from the head and draining tobthw sump?
Thanks des

Sent from my GT-N7105 using Tapatalk 2

[Rusty]

Those numbers are

[S2SE]

Yes im taking from the valvecover at the rear and from under the intake manifold.
But they just go to a bottle which I have to drain myself if they get filled. Going to make a better catch can later

[diesel des]

OK, the valve cover it one is still using the pipe with the holes you drilled?

Sent from my GT-N7105 using Tapatalk 4

[S2SE]

Yes its still the one with the holes drilled in it! But its not 3mm holes as I wrote earlier, its 6.5mm holes!