oil catch tank argument!!!

[novaboyopr]

the old pub chat argument me and my mate are having about oil catch tank fitting.

the argument started when he viewed my engine bay after i fitted a catch tank to stop my bay turning into an oilly mess and getting black flagged at track days.

ive fitted said catch tank to my c16xe runing ITB'S like so : main breather from crank to rocker cover still fitted, the pipe that use to run into the inlet next to it on the rocker cover now runs to my catch tank, which then vents to air as im running jenveys and thus can no longer route it back into the inlet.

the argument starts...

he states that i should have it routed back into my inlet or not fit one at all as its wrongly fitted anyway and should have a vacuum sucking on it to create a negative pressure to balance the crank case.

i strongly disagree 1. there is no way im going to plum it into my jenveys when all ive fitted it there for is to catch the oil that use to go all over my bay. 2. in my opinion it doesnt matter if its venting to air or back into the inlet as the crank will never pressurise (you cant pressurise a bottle with a hole in the side) which is what the breather system is there to do anyway regardless if its going back into the inlet.

so lads settle this one and whats right and whats wrong. lol lol

[AlexW]

Im lead to believe that the small vaccum pipe that is on the rocker on a baby valver should still be connected, which makes sence i guess, as it does draw it into the catch tank then.

[mk1nova_rich]

definitely dont put the breather into the manifold with ITBs as you are sending all the oil vapour to one cylinder instaed of across all 4!!

And you sound to have it set up right, i would ignore your mate lol

[novaboyopr]

awo6 i cant run that vacuum pipe due to my jenveys either, if my catch tank just vents to air surley it would struggle to vacuum the rocker anyway.

[mk1nova_rich]

breathers dont need to be vacuumed

[novaboyopr]

thats what i thought as long as the crank doesnt get pressurised its fine.

he says that it needs to be vacuumed to the inlet to balance the pressure in the crank

[novaboyopr]

http://www.ten-tenths.com/forum/showthread.php?t=91832

just found this. seems theres arguments for and against all over the web.

seems some people just vent it to atmosphere and some play around with vacuuming the crank to gain horsepower but most say that getting a vacuum from the inlet is the worst as the oil vapours still enter the inlet, apparently fitting a one way valve and getting a vacuum off the exhaust is the best way as the vapours get burnt in the exhaust while still creating vacuum.

[Stuart]

Using the vac from the intake would get more crank case pressure out which might result in more power..... BUT the contaminated vapor going into the intake charge will also lose you power.

What you could do if you care is to get a crank case vac pump from the USA, they arent cheap though :(


or leave as is and accept it works well enough

[jonn]

on my x16xe i have that pipe going into a coke bottle because i fitted a powerbox

[novaboyopr]

i wasnt looking at vacuuming my crank just stubbled across it there was someone talking about them pumps. they run them with there dry sump system and can get 70kpa of vacuum in the crank but he said its not really worth it for 1-2% hp increase.

so i guess the conclusion is that running to atmosphere isnt wrong nor is having it in your inlet but i would rather not have oily vapours running back into my inlet. so o-zone layer here the oily vapours come. lol

[MARTIN KELSON]

This was on SBD website

http://www.sbdev.co.uk/Info_sheets/Oil_systems/1.6L%20Breather%20Mod.gif

Presume where you have yours venting to atmosphere they run a line back to sump.