It seems like every thread I find on catch cans says something contradictory to the last. Not to mention they're all 10 years old.

I have 2x -10an Fittings welded in my valve cover. Is it alright if I plug the hole on the block and just run the 2 -10 fittings to the catch can and that's it? Or do I need a 3rd line from the block.

350whp power goal D16.

 

I have the same question.

 

I have and have had forever, my setup venting from the valve cover. With the block plugged. Originally was goin to go off of the block. But one allen fitting round. Higher HP setups mite have their setups from the block, one or both sides of the valve cover

 

Read the catch can sticky created by TheShodan. It should answer your question.

 

That is a very good write up, But I can't seem to figure out why they did the check valve off the valve cover.

Under vacuum that wouldn't create much vacuum in the block as it would just be pulling air through the catch can filter, through the an lines, into the crankcase.

I have a D series so I don't have the freeze plugs to tap into. However, in a practical sense, the block and the head have 4 very large oil drains connecting them, making them pretty much the same air space. So the 2 -10 An fittings seems to be identical to having 2x -10 fittings in the block.

I think that does answer my question though, I could just block off the black box instead and forgoing the drainback. I have emptied a many of catch cans and as much as he says the condensation is fine, I cannot bring myself to let that sewage back into the engine.

​​​​​i've read the sticky in the past but it always confused me being for B series, I'm a d guy. But looking at it with fresh eyes and further inspecting my block it makes sense.

As it sits the 2 -10 fittings on the valve cover will go to a catch can. The block box will be blocked off with a freeze plug, and the valve cover nipple will have a vacuum line with a check valve.

Now if only I can decide whether to vent the catch can or run a line to the turbo inlet.

 

The check valve is used because the canister and valve on the block have been removed.

 

I understand that part.

The part on confused by is it's relevance. It's hooked up like that to pull vacuum on the block just like the stock pcv system does. But it doesn't seem like it would pull much vacuum when there's so much crankcase ventilation. Rather than pulling vacuum in the block, it's just going to be sucking air through the catch and -10 lines

 

Theres no need for a one way valve in an atmosphere vent system. If you have 2 -10 lines, run to the catch can that has a breather filter. No need to run a 3rd to the block port, just empty the tank when needed.

 

I'm running 3 -10AN port catch can setup. 2 at the valve cover and one to where the "black box" was. Catch can has a filter on top and bottom drain that "mysteriously" dumps somewhere in front of the transmission.. LOL

 

Yeah, that's what happens with over pressurization.. I had the same issue until i recirculated back into the block itself.