catch can and turbo

[malibud]

Most all the set ups I have seen take

the PVC valve(breather) from the rocker cover <----> to catch can <--->Block vent to catch can

 

can Catch has a vent...

 

 

So my shop teacher said this was not a good idea because the PVC valve needs vaccum

Any other ideas ?

or is this acceptable on a L28 turbo ...

The vented block breather is making a mess out of my engine bay ...

[Graphitez]

P-C-V   ( Positive Crankcase Ventilation ) valve. Home depot has  PVC in the plumbing section if you need it! Please confirm this with your "shop teacher"

[seattlejester]

Edit: nevermind I just got your question.

 

Yes you could route both breathers to a dual port catch can. You just have to make sure the catch can is one with a dual inlet instead of a single inlet and a relief outlet. I think my Moroso catch can is that type, dual inlet, filter on top with baffles, and a drain at the bottom.

 

You would have to make sure you block the vacuum source for the PCV since that would be a big air leak.

 

From an emission/efficiency standpoint, your shop teacher is correct, the vacuum helps pull the oil vapors from the crank case and then burns it up via the combustion cycle.

 

Some reading says that the movement of the crank is enough to move some of it out. Without having the catch can hooked up to a vacuum source, you essentially are going to start building a collection of oil instead of having the oil burn through the combustion cycle. 

 

Each has it's own merits, without it going through the intake, it has less of a chance of depositing itself and coating the intake tract, with it going to the intake you have a sealed system, no chance for exterior contaminants to enter the oil system.

Edited December 17, 2014 by seattlejester

[malibud]

Ok, got it sorry rehabbing a house. Got it. I have a two-way catchcan, baffled, vented and bottom drain.

[LanceVance]

I've been eyeing a solution made for the aircraft industry that seems to be much simpler. It's an air/oil separator that would be installed inline the standard crankcase vent to intake manifold flow path; nifty part is, there is no drain tube, and the condensed blow by returns to the block via the crankcase tube.

 

Proper filtration, along with a reasonable oil change regimen should prevent any issues from the blow by sludge that people like to show off in their catch cans.

 

 

http://www.airflow-systems.com/air-oil-separators/

[Tony D]

The "P" is Positive, and that means vacuum is a motive force to actively run the crankcase pressure at Zero Pressure or lower.

It doesn't need to be engine vacuum, putting the lower block vent to a Vac-U-Pan ejector in the exhaust will draw vacuum at higher engine speeds to suck out blowby.

 

Simply venting it is OK but you lose horsepower over running a negative pressure in the gearbox.

 

Even with a catch-can, you can apply vacuum after the separator to draw a vacuum, but a filtered fresh-air source is required to clean out combustion vapors in there.

 

A PCV can be as simple as a 0.069" orifice in the tube directly to the manifold, it doesn't HAVE to be a big air leak to be effective. It's how Mitsubishi did it for years. When you run a MAP based EMS that is part of your idle air bypass circuit! In fact, there is a Mitsubishi PCV Assembly that plugs right into the hole in the block once you pull out the tube for PCV...time spent at the Autozone PCV Selection rack reveals a lot of possibilities!