pcv valve, catch can

I’m sorry i know this has been subjected a lot but I have tried to research it but end up confused still, so if you do a catch can on a n/a car for the pcv system how is it any diff then a reg pcv if you still just run it back to the intake, and on a turbo car running it into the turbo intake wouldn’t that stop up the turbo with that crud, I’m wanting to do this to “help” my engine but it all seems to be the same haha and the out that leads back to the intake they call a pcv valve how do you get a pcv valve on a catch can (yes I am that confused) so please some one clear this up and lmk the best way to do a catch can setup for my pvc system on my n/a im going to be turbo later on but for now i just want it to help my engine if it does, thanks.

When doing a catch-can system, you route the breather to a can. There should be no return-line to the motor, otherwise youre defeating the whole purpose of deleting the oem PCV/breather system.

this is NOT my image… but look at the fittings on the valve cover… they go to a can that has a filter on the top. There is no line that goes back to the intake tube… There is no return line to the motor.

but isn’t that one a oil catch can the other is a pcv one isn’t it i was reading about it and they said it wouldn’t work w/o the vacuum that it would fry your rings thats were i got confused lol.

The oil catch can replaces the entire pcv system… the ‘black box’ on the back of the block, the pcv valve, and the tube that goes to the Intake Manifold. You remove the black box and install a plug in the block… then you run your catch can lines from the valve cover. Instead of plugging the block, you could install a nipple, and run a line from that to your can, but I like running them from the valve cover.

On a built and tuned motor, having your IM suck that crankcase gas and oil into the motor will not only throw off your tune, but will cause sludge and build up in the IM and valves.

Soooooo… you run the new catch-can lines to an external source (catch can), and have it NOT run back to the motor.

thanks man good info one more question when ppl eliminate the valve to a catch can why do they run it to the turbo air intake for vacuum wouldn’t the gases clog up the turbo?

[QUOTE=unified112;2204307]When doing a catch-can system, you route the breather to a can. There should be no return-line to the motor, otherwise youre defeating the whole purpose of deleting the oem PCV/breather system.

this is NOT my image… but look at the fittings on the valve cover… they go to a can that has a filter on the top. There is no line that goes back to the intake tube… There is no return line to the motor.[/QUOTE]

[QUOTE=unified112;2204389]The oil catch can replaces the entire pcv system… the ‘black box’ on the back of the block, the pcv valve, and the tube that goes to the Intake Manifold. You remove the black box and install a plug in the block… then you run your catch can lines from the valve cover. Instead of plugging the block, you could install a nipple, and run a line from that to your can, but I like running them from the valve cover.

On a built and tuned motor, having your IM suck that crankcase gas and oil into the motor will not only throw off your tune, but will cause sludge and build up in the IM and valves.

Soooooo… you run the new catch-can lines to an external source (catch can), and have it NOT run back to the motor.[/QUOTE]

Not so, the system you are describing is known as an open system, you can also run with what is termed a closed catch can system with the catch can acting as a scrubber to remove oil vapour and pollutants from crankcase gasses and still have a return to the intake manifold. The system still functions through manifold vacuum similar to the PCV/back of block black box however accumulated oil and pollutants are not mandatorily returned back to the block as in the black box system.

You know, try to keep the environment CLEAN with DD!

True… after reading about closed systems there are indeed units that have stainless mesh systems that ‘purify’ the crankcase gasses and separate the oil and keep it in the can while fresh air is returned to the motor.

Either system will work, but the open system is for ‘off road use only’.

well this has helped so what could you put in the can to catch the vapors and gases thanks guys i need this cleared up some haha

if you bought an aftermarket catch can it should have the necessary baffles in it. if you want to run a closed system all you do is run the hose from the PCV to the catch can, then from the catch can back into the intake manifold. i have a setup similar to the one unified112 posted although i have one big tank instead of two small ones. it’s ridiculous how much crap ends up in that thing!

well thats cool would ebay ones have the baffles in it? if you take off the pcv box and plug that then put somthing to run hoses from either side of the places beside the oil filter could you do it the same?

not sure what you’re asking. are you talking about the two ports on the back of the block where you unscrew the 14mm hex plugs and install -10AN hoses? for a turbo car that’s good along with two -10AN hoses on the valve cover but for a stock engine that’s useless. a simple closed catch can between the pcv and intake manifold is sufficient for a stock engine. i’m not certain that the ebay cans have baffles in them since usually ebay stuff is cheap as hell and isn’t fabricated properly. you would have to search for that.

A catch can system is a catch can system… having a/n fittings in the back of the block works for NA and turbo alike. The only difference is that with a turbo application there will be higher pressures in the motor, so it is wise to have more breather tubes (ie using two on the back of the block, rather than just one).

I could see using four fittings if you were pushing like 600+whp. But for most street turbo’d cars, two fittings is fine. NA cars can do with just one, whether it be in the valve cover or back of the block.

thats what i was talking about sorry i didnt know how to explain it i was thinking about going ahead with the 2 since im going to be turbo’d soon i hope haha