oil catch cans

[bbenny]

Im just about to install my catch can (on an RB20DET), but just wanted to be sure i am fitting it correctly, ensuring no damage to anything else.

i have done some research on the forum so dont tell me to do a search please.

Basically i want to know if it is ok to block the intake line (plug before the turbo) and the valve in the plenum (PCV) then run a line from each rocker cover to the catch can.

is this correct?

The can only has two fittings for hoses. will i have to make another to fit a small filter, or some sort of breather/venting hole?

One other thing - is it true that doing this will cause dangerous vapours to damage my head?

i dont want any blowby oil or vapour running back into the intake system, as i understand they promote detonation.

Any advice would be much appreciated.

p.s i do understand that any vapours venting to atmo is illegal. but i am not concerned as its probably for track use only.

thanks

Ben

[BOOSTD]

If your catch can has no venting hole: one hose goes to the rocker cover and the other to the sump. This way needs the PVC valve left open.

My catch can has a filter and clogs up very quickly which causes it to blow off and splatter oil all over the place. A Oil Air seperator is the better option(like you have) IMO.

[bbenny]

according to the box it came in, im supposed to have one line run from the rocker cover to the can, then the other line from the can to the intake (before turbo) that will stop oil from getting into the intake, but continues to let the vapours flow back into the system.

i want to remove these vapours from comming back in.

how would best acheive this with the system i have?

[BOOSTD]

There shouldn't be any vapours if the can works efficiently.

[bbenny]

well this has no internal filtering system, it is simply an aluminium can, it just stops any liquid from circulating back to the intake. if i drill another hole into the can and fit a breather. would i be able to block both PCV and the intake plug safely?

[BOOSTD]

All that comes from the rocker cover is vapour!!! No liquid. I don't understand. most cans work from the vapour hitting a metal tongue which the vapour sticks to and drops the the bottom. Are your sure your is just an empty can?

[Guest INASNT]

If the can is empty without any ventilation then it will do nothing as the equal pressure on the intake and outake will just pass oil/vapours straight through the can.

[bbenny]

haha ok, maybe im not explaining myself properly. i understand that it is a straight can, designed to catch the oil from the rocker cover and only send air to the intake. HOWEVER i want to know if it possible to block the PVC and intake plug, and run two lines, one from each rocker to the can. if i do this will i have to insert a breather in the can?

is this safe on the engine?

i know it is illegal to vent those vapours to the atmo on a street car, but this is not of concern.

any advice would be great.

[BOOSTD]

yes that will work, I have the same setup. Be prepared to clean the filter monthly.

[Gradenko]

bbenny, ditching the PCV is a good way to go. Stops all chance of the motor ingesting oil vapour. Just be sure to vent the catch can in some way or you'll be in all sorts of engine trouble. Way I would do it is run one hose for both cam covers (merged or like the factory setup) to the catch can, then use the free hose connection on the can to run a hose into the nether regions of the engine bay and point it at the ground.

[ed]

Originally posted by INASNT

If the can is empty without any ventilation then it will do nothing as the equal pressure on the intake and outake will just pass oil/vapours straight through the can.

so you're saying the GReddy, CUSCO etc cans won't do anything?

[BOOSTD]

GReddy and CUSCO aren't connected with both lines to the rocker cover. They sit in between the feed to the intake. Vacuum on one side and crankcase pressure on the other.

[Guest INASNT]

Originally posted by ed

so you're saying the GReddy, CUSCO etc cans won't do anything?

what boostd said!

[ed]

how do these things work to seperate the oil from the air?

[bbenny]

yeah i have the greddy one. i dunno if its just my car, but i clearly get oil running into the mouth of my turbo. thats one reason why i invested in the can. the greddy one catches that oil in the can and allows only gas to flow to the intake.

other models actually have a filter and claim to remove any oil vapour or harmful gasses (impossible) and only send purified air to the intake... but i think the best way is not to let any of that crappy air, filtered or unfiltered back into the intake.