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Oil Breathers

Old 06-19-2011, 08:18 PM
85300td's Avatar
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Join Date: Sep 2010
Posts: 90
Default Oil Breathers

I'm in the process of cancelling my air intake box for a preferable fram paper cone filter. I'm not too concerned about noise or HP increase as I doubt this will help. I'm really just interested in easy access to air filter, turbo, motor etc.

Here is my question:

some guys run custom home depot " plastic" elbow pipes with reducers to fit the turbo intake and the paper filter elements (that i get). However I have noticed that some people run their hose
from their valve cover into an (oil/gas) separator than dump the oil back to the crank through oem pipe fittings. And most simply just run the line straight from the valve to the body of the air intake. Why? And what happens to the oem pipe that feeds oil from the valve back
To the motor?

Thanks and cheers

Last edited by 85300td; 06-21-2011 at 03:11 PM.
Old 06-21-2011, 02:57 PM
85300td's Avatar
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Join Date: Sep 2010
Posts: 90

Assuming that I do have minor blowby, if I choose to route line
directly from the VC -to a good separator-to the air intake body would not the separated gases cause a nasty oil mess inside my intake manifold? Will it not be a similar effect to what the EGR does with the recycled exhaust fumes?
I have seen a many intake manifolds literally pooled
with oil. Might this be the cause?

What brand separators are u using or recommend if u dont mind me asking? How long do their filters last and need replacement..etc
Is there any benefit to routing separated gases directly into the air intake body vs just dumping it off through a draft tube after separation?

Why is it that most manufacturers choose the former (separated gases to intake)
over the ladder( oil back to oil pan) and dump gases? Is it a emissions mandate or something?

Lastly, glad ur still around, ur very helpful.

THanks in advance.

Oh, one more thing. Less oil consumption is a good thing. Right?

Last edited by 85300td; 06-21-2011 at 03:13 PM.
Old 06-22-2011, 02:04 PM
85300td's Avatar
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Join Date: Sep 2010
Posts: 90

I dont have an intercooler, so here is what Im thinking.

VC line-to an Oil/Air separator, oil drip line from the Separator to the original OEM oil sump return pipe, and the gases from the other line of the Separator into a drip catch can, then from there flush final vapors down to the street or into the intake body to re-enter the combustion chamber as part of a fresh charge of air and fuel to recombust.

Also, I read recently that oil vapors coming from the separator should never be reintroduced directly into the intake or throttle body (yet I see it done 95%) because those vapors are not always burned by the motor and are returned polluted in the form of vapors into the motor? That has me scratching.. Is it a PCV vs some other sort of air movement??

Would be helpful also if you can show me how that separator was built. That is, what ever it is u are using to separate.8)

Thanks for all your help.

Last edited by 85300td; 06-22-2011 at 04:29 PM.
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