327 Rwkw 760Nm Xt One Tonne Ute (Was A V8)

[genuine honest person]

Will post more pictures of how I will set it up soon. Had a bad thing happen to our dog tonight he fell down the bed when he tryed to jump up .he tore a ligament and needs a operation on the knee. $2000 plus to fix him . Poor litle fella is not happy .have to look after him now as he needs constant care so he does not hurt his other leg or knee .

[barnz]

also fair point, factory setup does this just find doesnt it? it has a vac line to the mani with a check. and a breather to the intake between the air filter and the turbo. the air ruhishing past the breather in the intake creates a bit of vacuum even under boost and pressurised crank case gases just take another route essentially.

2 cans, 1 with a check to the manifold vac. The other plumbed in between the pod an the turbo inlet.

[genuine honest person]

Can I have a picture of it please.

[OZYWALKER]

Could be done with the one can that way, just more plumbing. You'd have to make sure the check valves don't leak, would be a pain if they weren't reliable and make sure the check valves aren't causing a restriction in the line as well.

To much effort and $$$.

[genuine honest person]

Will just do it as I think will work .lol to hard basket

[HI PSI]

3 hours ago, barnz said:

why not just plumb back to the intake manifold like factory and put a check valve on that line to stop your can getting boosted..the idea of a catch can is to trap the atomised oil so you dont suck sh*t in. If your going to vent a catch can to atmo...may aswell just put filters your rocker cover and degrease the bay regularly. its as illegal but alot less complicated..

 

 

Isn't the catch can designed to relieve crank case pressure, which could be from blow by. Being that maximum crank case pressure would be when the car is on  high boost, how would the check valve work when the one way valve would be held shut due to boost pressure? 

In order to be as legal as possible, I ran 2 x 12an feeds to my catch can, with a 16an return back to the intake. No valve was required for my system. Just remember, that the catch can needs to be efficient, as oil contamination fed into the intake can/will cause detonation. For this reason, take note of the designs of the  Peterson and Morosso catch cans. The inlets of these cans force the air onto an inner cylinder wall/liner, which forces the air/oil downwards into the stainless mesh, before it is drawn upwards to the output hose.

 

On a final note, the bigger the boost, the bigger the catch can lines need to be. Keep up the good work bud. Loving the build. :D

Edited 07/06/16 12:24 PM by HI PSI
Typo's

[barnz]

? The breather can vent excess pressure into the intake when the manifold isnt under vacuum. Its just a circuit fresh air in one crank case gases go out the other under vacuum. So why wouldnt any excess pressure be vented out the breather when the loop is closed. There will be some vacuum on the breather when sucking in that much air at high boost but not fresh air inlet for the system to reverse.

the check valve just prevents a boost leak

but its not sealed so why wouldnt any excess pressure go back into the intake? Its pretty clear it does given the oil that accumulates in the intake pipe and compressor housing without a catch can.Factory principal seems fine it just has no catch cans

Or is a single breather as one is essentially closed under boost seriously not enough when smashing 40psi?

[genuine honest person]

Will have to look into it more .but could I have pictures of set ups please

[barnz]

I dont have a diagram or pics atm but can take some later.

The factory setup has the pcv valve at the rear, they can call it a pcv valve all they like its just a check. That goes to the manifold and sucks in gas under vacum. the most forwad fitting on the rocker is the breather, it lets in make up air as the gases are exhausted or sucked into the manifold if you will. Even when the check is closed by boost pressure the crank case is not sealed as the breather is open. As I said it definitely does vent under boost coz of blow by which is evident from the oil that builds up in the intake piping.

The reason you need a check after the can on the vac line rather than at the rocker cover is to stop the can pressurising. The reason the factory puts a check in is to prevent boost being pushed through the crank case and out the breather. Similarly a pcv on a NA engine has a spring that's just a little to weak to hold it closed under idle vacum, as the vacum decreases when the throttle is open the spring closes the pcv which prevents a vacum leak. I dont understand why ppl dont replicate the factory cct with some cans as it is legal and keeps almost all the sh*t being sucked back into the engine. Its not as ideal as venting to atmo in respect to sucking in 100% clean air but its legal and nearly the best of both worlds. Seems like a crazy amount of blow by if dual breathers are required to prevent excessive crank case pressures.

[OZYWALKER]

You'd be surprised how much even the stock motors breath. I've seen my catch can and a few others have visible clouds of vapour come out after a few dyno pulls.