Advice on PCV setup

[Tzaks]

Hello!

After looking @fmorelli's PCV thread and reading through the replies I had the idea of re-designing the PCV system using inspiration from him and @Panzerfaust.

I've ordered the ACfab PCV fittings AN10 for the high side and AN8 low. Please have a look at the schematic below of the setup I have in mind.

Low side:
VC > AN8 fitting > OCC > Upgraded internal metal PCV valve mounted in line or 2jz PCV valve > One way check valve (allows flow to the Intake manifold but not to the OCC) > AN8 with 1/8 NPT hole for DV vacuum lines > Intake manifold

High side:
VC > AN10 > OE Flapper > OCC with filter on top > One way check valve (allows flow to OCC but not to inlet) > Inlet

For the OCC I plan to use the same red one used by @fmorelli here, low side without filter and high with filter.
I'm also planning on getting the Oil cap breather from VTT just to make sure the VC doesn't ever see positive pressure, head ports will be blocked as well.



Ideally, I'd like to find a solution that would use this setup and get rid of the flapper. Any suggestions are welcomed and please let me know if this wouldn't work.

 

[The Convert]

Your high side valve needs to allow flow from the OCC to the inlet. That’s how it moves air out of the crankcase for evacuation.

 

[Tzaks]

This is why I was thinking of using a filter on that OCC. Would it be better to remove the one way check valve from the high side?

 

[Cruizinmax]

If you're routing the high side back to the inlet, no need for a extra filter on the high side catch can. The check valve should also be removed.

 

[Tzaks]

Instead of running a high side OCC, can I get the vacuum relief valve from VTT and connect straight to an10?

 

[martymil]

That diagram is pretty good except

If your going to run oem flapper and pcv vale then DO NOT run 1 way valves and no need
for filter on high side catch can as it runs to rear inlet, save some money.

The flapper is a relief valve as well and buy running the 1 way valve your sealing the system which will make your seals whistle badly.

Instead of running a high side OCC, can I get the vacuum relief valve from VTT and connect straight to an10?

Its a good idea to run a high side catch can as it will tell you if there is something wrong with your motor
if it starts to collect large amounts of oil as you shouldn't see any or very minimal there and stop smoking by oil getting pulled into the turbo at high rpm.

Yes you can run the relief valve but you need to get rid of the flapper and run a 1 way valve, then you will need a vac gauge
to dial in the amount of vacuum inside your motor to do it properly.

 

[Tzaks]

That diagram is pretty good except

If your going to run oem flapper and pcv vale then DO NOT run 1 way valves and no need
for filter on high side catch can as it runs to rear inlet, save some money.

Can I run a one way check valve instead of the OEM PCV in-line? I saw the vtt kit has shims that can be removed for vacuum to be adjusted between 10 and 16hg

 

[martymil]

you can run a one way valve instead of the pcv valve.

The only time you will the the vacuum relief valve is when you remove the oem flapper valve and/or run a 1 way valve on the high side.

 

[wireboy]

That diagram is pretty good except

If your going to run oem flapper and pcv vale then DO NOT run 1 way valves and no need
for filter on high side catch can as it runs to rear inlet, save some money.

The flapper is a relief valve as well and buy running the 1 way valve your sealing the system which will make your seals whistle badly.


Its a good idea to run a high side catch can as it will tell you if there is something wrong with your motor
if it starts to collect large amounts of oil as you shouldn't see any or very minimal there and stop smoking by oil getting pulled into the turbo at high rpm.

Yes you can run the relief valve but you need to get rid of the flapper and run a 1 way valve, then you will need a vac gauge
to dial in the amount of vacuum inside your motor to do it properly.

Question for you Marty. Where did you tap in to get your crankcase vacuum reading with the VTT valve cover? Possibly a modified screw in plastic oil filler cap (part number?) with the same threads? The VTT valve cover uses a screw in cap as opposed to the factory cap with a turn and lock.

 

[STE92]

I just removed high side hose and used otc vaccum kit comes with rubber piece you can stick in the hose and get your reading

 

[wireboy]

I just removed high side hose and used otc vaccum kit comes with rubber piece you can stick in the hose and get your reading

Thank you!

 

[martymil]

I take readings of the valve cover fitting with an 1/8 npt adapter.

 

[wireboy]

I take readings of the valve cover fitting with an 1/8 npt adapter.


View attachment 49196

I see. I was using a 1/8 npt on the factory oil filler cap. The new cover uses a different cap. I am going to try measuring off the high side as mentioned by another. Thanks for pic. Looks good

 

[Tzaks]

After taking apart the flapper hose I noticed it has a small hole for allowing the crankcase to breathe and regulate vacuum. For some reason I don't stand that flapper hose, perhaps because I want to make everything AN braided lines and it ruins the whole mojo.

So I went back to the drawing board and got an idea, if I use the valve cover AN10 adapter and then connect it to this adjustable valve (see picture below), it would eliminate the flapper, keep the AN10 setup and connect to the catch can. I am in the process of making an oil cap with a fitting that would allow me to measure vacuum at idle so I can adjust the valve accordingly.

For how many inHG should I aim?

 

[martymil]

You really want to use a proper vac relief valve but thats up to you, I aim for between 2 and 3 inhg considering factory is less than 0.5inhg.

 

[Tzaks]

Hey Marty,

Thank you for taking the time to reply. I understand that a vacuum relief valve would be the best option however, since BMW got away with a whole in the flapper, you think it could affect the engine negatively if the same hole design is implemented but with a narrower hole?

- in this video you can see the hole under the flapper that allows the crankcase to breathe and my goal is to adjust the aftermarket aN10 so it's slightly narrower. I will aim for 2-3 inHG, I assume at cruising speed this should translate in 10-15 inHG?

 

[fmorelli]

I suspect one of the things you may wish to consider, when looking at the BMW design, is what the BMW design was seeking to accomplish. My suspicion is that you are not running a stock engine (component/power/etc).

There is a lot of discussion on vacuum setups for this car (and not very black and white). On this subject, if I was doing what you are doing, I'd look at martymil's solution using the VTT vacuum relief valve. This is a clean install, I'm not sure what's not to like (I will eventually go to this when I come back through my system).

IMHO, @Chris@VargasTurboTech this mount would be a good product catalog add for VTT.

Filippo

 

[Tzaks]

Hi Gents,

I have finally got around to installing this new setup on the car. I used an an8 connection in the VC to an8 at the catch can. Catch can is then connected to the manifold with a one way check valve pointed towards the manifold ( CC > Intake manifold) and an adapter for 1/8 npt for the Nylon vacuum lines.

I tapped the ports in the head and plugged them at the same time. I've also installed a restriction on the AN8 hose leading to the manifold (before the One way check valve) in order to replicate the small passage the OEM PCV has.

Now, I have a loud whistle and the vacuum tested at the CC is at 16 - 17 inHg @ idle.

I am waiting for a fitting to install the VTT vacuum relief valve the same way @martymil did his.

Do you think the VTT relief valve will sort this? I wanted to have an MVP and theoretically, from what I read and understood, this system should work even like this.

 

[Cruizinmax]

Hi Gents,

I have finally got around to installing this new setup on the car. I used an an8 connection in the VC to an8 at the catch can. Catch can is then connected to the manifold with a one way check valve pointed towards the manifold ( CC > Intake manifold) and an adapter for 1/8 npt for the Nylon vacuum lines.

I tapped the ports in the head and plugged them at the same time. I've also installed a restriction on the AN8 hose leading to the manifold (before the One way check valve) in order to replicate the small passage the OEM PCV has.

Now, I have a loud whistle and the vacuum tested at the CC is at 16 - 17 inHg @ idle.

I am waiting for a fitting to install the VTT vacuum relief valve the same way @martymil did his.

Do you think the VTT relief valve will sort this? I wanted to have an MVP and theoretically, from what I read and understood, this system should work even like this.

View attachment 51264

Do you have a path for air to enter back in to the crankcase? If not you are pulling too much vacuum in the crankcase and that is causing your whistle. The filter at your oil fill cap, does it allow air in the crankcase or just out?

 

[Tzaks]

I will have one soon with the vacuum relief valve from VTT and a similar implementation as it is in post #17

The filter on the oil cap will only allow positive pressure out but nothing in.

I'm a bit concerned that fitting the vacuum relief valve won't solve the issue but maybe I'm just getting ahead of myself.