BT Crankcase venting ideas and current setups

[Erich]

Preferred method for venting seems to be a rod through the block. Very popular on this site.

I run the stock location (using a block off plate) to an exhaust venturi and then the valve cover to the intake manifold.

[06Speed6]

I have tried both krankvents and a stainless mcmaster valve and both worked great, I am with others that dipstick probs are boost leaking to the cc.

I need to finish my cc vent/venturi setup, its seriously sweet. Thanks for reminding me.

[chimmike]

Are these the check valves from McMaster? McMaster-Carr

Also, I see SilverDemon recommending a check valve between OCC and PCV.....is there a need for a check valve after the OCC between it and the venturi?

[SilverDemon]

Yes, potential back fire might not be the greatest for the catch can.

[chimmike]

Originally Posted by SilverDemon Yes, potential back fire might not be the greatest for the catch can.

Exprosion in catch can from fuel/oil vapors, hahaha.


Now which McMaster check valve? the "stainless steel" ones? Good Christ those are expensive. None in 5/8" either.

[SSinstaller]

You want check valve 7775k54, and fittings 5346k66.

[chuckms6]

The vw 1.8t uses a port on the turbo inlet pipe to provide vacuum under boost and a system of check valves to control airflow. I simplified mine and connected to the tip fulltime since all three houses were cracking anyway. I was thinking our system used a method similar to this but I see now i'm wrong lol.

My method would be to cap the intake manifold port and install a check valve in the hose on the valve cover so air only flows from the intake to the valve cover and blocks airflow the other way. From the stock PCV go to the OCC then to a port on the TIP preferably close to the turbo for max vacuum.

An alternative would be to cap the valve cover so the system is always under vacuum. That would be favorable IMO.

Tapatalking

[Evan@COBB]

I have the stock PCV system with a MD OCC installed. Only difference is that I moved the valve cover vent much closer to the turbo with as big a line I could fit to it and I opened up the holes that the air travels through in the valve cover baffle an extra 0.020" or so, whatever seemed like the biggest I could go before the walls got too thin.

No problems at all.

[crazyp]

Originally Posted by Evan@COBB I have the stock PCV system with a MD OCC installed. Only difference is that I moved the valve cover vent much closer to the turbo with as big a line I could fit to it and I opened up the holes that the air travels through in the valve cover baffle an extra 0.020" or so, whatever seemed like the biggest I could go before the walls got too thin. No problems at all.

how much boost are you running though? unless its more than 26 psi it doesn't really help the convo. I only blow out my dipstick above that, as well as others it seems......

[PapaSmurf]

Originally Posted by crazyp how much boost are you running though? unless its more than 26 psi it doesn't really help the convo. I only blow out my dipstick above that, as well as others it seems......

My threshold was 27psi... Once I went above that it was dip stick shooting territory. I'm good now since I modified my pcv box


Sent from my flying tapadildo

[SilverDemon]

30+ psi

without poppage

[BigjohnB20]

Originally Posted by chuckms6 An alternative would be to cap the valve cover so the system is always under vacuum. That would be favorable IMO.

This is essentially how the Krankvents are set up to work except they allow venting of blow by gases under load. A check valve on the valve cover to TIP is open under vac (high load) and closed under low load (vac in intake manifold, simulating the cap'd VC). Then another check valve before the PVC is opposite, so closed under high load and open under low load (vac in IM). I have been running half the KVs for quite some time now. I don't have the PVC side installed, but I am on K04 so I don't have to worry about blowing the Dipstick. What I do have is a constant vac in the CC and have never once seen my turbo smoke in 40K miles.

Originally Posted by crazyp how much boost are you running though? unless its more than 26 psi it doesn't really help the convo. I only blow out my dipstick above that, as well as others it seems......

Do you guys that are blowing the dipstick have an additional check valve before the PVC. If you do all that pressure is coming from blow by which probably isn't very good. If not, it likely means the PCV is leaking boost and pressuring the CC.

[crazyp]

Originally Posted by BigjohnB20 This is essentially how the Krankvents are set up to work except they allow venting of blow by gases under load. A check valve on the valve cover to TIP is open under vac (high load) and closed under low load (vac in intake manifold, simulating the cap'd VC). Then another check valve before the PVC is opposite, so closed under high load and open under low load (vac in IM). I have been running half the KVs for quite some time now. I don't have the PVC side installed, but I am on K04 so I don't have to worry about blowing the Dipstick. What I do have is a constant vac in the CC and have never once seen my turbo smoke in 40K miles. Do you guys that are blowing the dipstick have an additional check valve before the PVC. If you do all that pressure is coming from blow by which probably isn't very good. If not, it likely means the PCV is leaking boost and pressuring the CC.

with the OCC kits we have they pretty much all come with check valves.

I'm good with 25 psi on stock block anyway. When I build the motor then I'll worry about fixing this issue.

[06Speed6]

I think I have the 4620k84 check valve, but the crack pressure seems high I remember mine being between .3 and .5psi to open. You dont want too much pressure to open because that pressure will be in the cc which defeats the purpose.

[SSinstaller]

Originally Posted by 06Speed6 I think I have the 4620k84 check valve, but the crack pressure seems high I remember mine being between .3 and .5psi to open. You dont want too much pressure to open because that pressure will be in the cc which defeats the purpose.

IIRC it takes at least 1 psi to open the high pressure check valves. That was one of the reasons I went with the quick opening brass valve, the other being the $150 price difference between the SS and the brass valves..

[bcmurphy87]

How much hose are you guys using to get the exhaust Venturi to the catch can?

I only have a 2 port catch can but I'm gonna put a T into the line going to the intake manifold and hook the Venturi line into there.


Can I get away with using the 5/8s heater hose from autozone?

[SilverDemon]

-10 pushlock hose from jegs is what I use.

it is oil resistant, I am not sure the coolant hose has the same rating. You might check it out before you buy. 10 feet should be enough.

[bcmurphy87]

What about his hose? it says its cleared for fluid transfer and vaccum applications?

Shop Watts 5/8" ID PVC Reinforced Braided Vinyl Tubing at Lowes.com

[SilverDemon]

I can't see the link on my phone, just make sure it is compatable with motor oil.

[Dano]

Originally Posted by bcmurphy87 What about his hose? it says its cleared for fluid transfer and vaccum applications? Shop Watts 5/8" ID PVC Reinforced Braided Vinyl Tubing at Lowes.com

FWIW I have been running that exact tubing on my OCC for 4 years...I however would not recommend it. it gets very brittle/hard over time and the clamps will not hold tight. When I recently pulled my IM the entire front of my motor and all the fittings were covered in oily residue due to the hose getting brittle and clamps not holding tight against the barbs. I would imagine it was causing a slight vacuum leak as well.

I need to replace mine soon with something more pliable.

[bcmurphy87]

I found this and i think its a winner!!

NAPA AUTO PARTS

[Dano]

does the store tell it by the foot? The PDF says available in 50' or 300' rolls.

Also they don't mention if it is vacuum resist but I suppose if it can handle pressure it can handle vacuum...someone that knows chime in pls.

[bcmurphy87]

yea its 4.99 a foot

[11cruzito11]

Originally Posted by SSinstaller You want check valve 7775k54, and fittings 5346k66.

You need two fittings for the check valve, right?

[SSinstaller]

Originally Posted by 11cruzito11 You need two fittings for the check valve, right?

Yes