Catch can summary

[Roadrunner]

For those with a catch can between the PCV and intake, do you also have a 1 way check valve in line so as to not push boost passed the PCV valve?
This is my current cold side setup but struggling to find a 3/8 valve that is suitable to air and oil/fuel. Plenty of them on ebay but they say for fluid only (fuel drain back prevention). Not that my PCV is leaking under boost, but a simple check valve is an added step of safety.

[rossint]

The Familia PCV for the turbo cars is a different part number but the same size as the mx5 one, it’s apparently better suited for boost.

[Roadrunner]

I have that one but there's many reports on Miataturbo.net that it still leaks under boost and recommend to run a check valve just before it.
So many check valves designed for fluids but can't find much for air line that isn't the size of my fist.

Wonder if a brake booster check valve would work and not deteriorate with oil and fuel vapours

[RS2000]

Fluid Power suppliers will have small pneumatic check/one way valves.
Brake booster check valves off the inlet manifold on old carby cars were obviously resistant to fuel

[RS2000]

On second thoughts, the booster check probably sees very little fuel vapour, even when the vacuum hose is attached to a manifold that has fuel mixture passing through it.

[Roadrunner]

This is the closest thing I can find to a check valve by a quality company. Shame about it being plastic, but if it works...
https://www.sparesbox.com.au/part/aeroflow-3-8-check-valve-for-brakes-booster-hose-1-way-valve-af59-1050

[Roadrunner]

Also of note with catch cans and venting, It's not just about venting through a can to catch oil, it's making sure the crankcase can vent more blowby than is being created.
Recently for shits and giggles I hooked up a boost gauge to an old oil cap. With the stock SE CCV setup, from 16psi/4000rpm to redline I measured 2psi in the crankcase. Not good.
Got a -12 outlet welded to the rocker cover and the internal passage drilled to a larger size and now there isn't any pressure in the crankcase right to redline with 21psi.
If you run boost, it's worth the test for the cost of a brass fitting and an oil cap.

[greenMachine]

^ Tiny hole mod. I think 12AN may be overkill, 10AN has sufficed for me, although I only have half your boost. Did you use a mesh filter medium on the last VC chamber?

My AN fitting is a press fit in the head, may have used some locktite also - no movement, and avoids marring of the VC finish. The factory fitting was removed and the hole drilled to suit.

[Roadrunner]

Figured if I''m going to do it I may as well go big
12an fitting is bigger than the stand-off on the cover, so welding was the only option. Going to blend the paint in by mixing some red and black wrinkle paint.