Oil catch can install

[Stoffa]

Ive removed my pcv and put a brass bung in the hole. also blocked the hole in the intake. if i have big oil dramas on the track ill run a moroso air oil seperator between the head breathers and my catch can and have the drain go to the spare bung in my sump

[Guest]

 Stoffa said:

Ive removed my pcv and put a brass bung in the hole. also blocked the hole in the intake. if i have big oil dramas on the track ill run a moroso air oil seperator between the head breathers and my catch can and have the drain go to the spare bung in my sump

isnt having the rocker breathers plumbed into pcv the same as open to vent? struggling to see where the leak comes from, someone wise needs to shed light.

People put filters onto their rocker covers all the time with no can but dont think it constitutes a vacuum leak well doesnt give fluctuating idle anyway.

[reaperblitz]

I'm just confused now cause all the previous engines Iv put catch cans on was straight forward. Now to a Subi block- its like with all the info on the net and speculation about what to do or not do its like umm...??

K if I tap the rocker breathers, run to closed catch can to air intake that won't get any oil as rocker breathers want fresh air in. Right?

The rear of the block has two bungs- one is crank case breather baffled and front side not baffled. One you can block off and weld shut of whatever and one you still need to run in system to the pcv? Is it at this point you want to add the catch can?

[Stoffa]

technically you should use two on a subie, one for the heads and one for the crank.

using a seal catch can defeats the purpose, you may as well just connect a hose directly from one head breather to the other.

the whole idea of a pcv setup is to remove blow by gasses, which are full contaminants, from your crankcase.

with a pcv set up it uses the venturi from the intake to remove the gasses.

you can run a vented catch can as the blowby gas doesn't count as metered air, well it is metered but the engine cant use it as its now in the crankcase and not the presurised side of the chamber.

the best way to remove the blow buy gasses is to use a vacuum pump and actually suck them out. the next best thing use a proper air/oil separator which will still be connected to the intake but if it works properly by the time it gets sucked back into the intake there wont be any oil left in the vapor.

the easiest way is to let the gas blow itself out, if you have a sealed catch can there will be too much resistance from the can being sealed. with a vented can the gas will follow the least path of resistance, i.e through the filter in the can.

most of the bad vapor and condensation comes from the crank, you wont get much from the heads.

IMO you don't want the condensation to be drained back to the sump as it contaminates the oil.

with heavy track cornering you end up with a build up oil oil in the heads that cant always drain back to the sump quick enough so it sloshes out the breather holes.

[Stoffa]

 evowrx']

[quote name='Stoffa said:

Ive removed my pcv and put a brass bung in the hole. also blocked the hole in the intake. if i have big oil dramas on the track ill run a moroso air oil seperator between the head breathers and my catch can and have the drain go to the spare bung in my sump

/quote]

isnt having the rocker breathers plumbed into pcv the same as open to vent? struggling to see where the leak comes from, someone wise needs to shed light.

I dont have them plumbed into the pcv, I dont have a pcv. read my above post. its not letting metered air out

[reaperblitz]

Cheers Stoffa. you deserve a drink for that explanation. (thumbs up)

[Stoffa]

http://forums.nasioc.com/forums/showthread.php?t=754710

http://forums.nasioc.com/forums/showthread.php?t=1231233

http://forums.nasioc.com/forums/showthread.php?t=1594337

http://forums.nasioc.com/forums/showthread.php?t=2161719

http://forums.nasioc.com/forums/showthread.php?t=1944342

[reaperblitz]

Moroso's looks like a baws.

There's another smaller version of the air/ oil separator, kinda looks like a sandwich plate.

Guess sourcing a nice catch can for the job is the next thing