4age after turbocharging. What do I do with the breating cam cover??

[killapotatoe]

Hello Forum,

nice to be here. I have a 4age I have turbocharged sitting in a ae86. I've bunged up the plenum ( from where the original breather pipe went from the cam cover to the inlet plenum )

Now I have the cam cover pushing out a lot of air. Like a vacuum on backwards.. What can I do with this breather pipe? Its not blowing out oil or anything but it makes the car cabin smell of fumes.

I've consider a catch can with a small filter on it and another exit going back into the pod filter

Any help, pictures, advice is wholesomely appreciated.

http://dsrturbo.com/gallery.php?cat_id=5

[trikzlane]

just run it into a catch can with a filter, otherwise you can pumb it back, its up 2 you

[Sam-Q]

you can never block off the breather to an engine, it will cause it to not breathe and hence not have high pressures. What you propose sounds ideal.

[haveaparty]

How bout u put the breather pipe back on. Mine has a oil breather in the line.

[Sam-Q]

Now I have not paid attention to what is normal on boosted engines but I would think that putting it pre-turbo would get the best ring seal.

[killapotatoe]

OK Thanks a lot. I'lll fit a catch tank to it with the filter :)

I went to a wreckers last week and picked up a honda break cyclinder ( one way ) valve. Hoping that when the plenum was under pressure the valve would stop the pressure going into the cam covers. but not under load let the rocker covers blow back into the plenum. This theory didnt work and resulted in a lot of SMOKE!! out the back :)

Thanks a lot people

[Sam-Q]

the reason why your engine smokes is because the crankcase pressure grows to a point where the combustion pressure isn't enough to push the rings outwards to seal properly.

[lolwat]

point it straight at the ground

[FAST EDDIE]

if ur going to run lots of boost you NEEd to have a breather on both rocker covers and you need to have a big breather (bigger thatn the std one)or it will just overfill the rockercovers with oil and spew it out the breather, ive also done the aim it straight out to the ground but this was in a street car with 12psi so never got too much of a hard time!

[johl]

Do you need to block the inlet breather or does it not leak boost? Pretty sure i'v seen heaps of people run lines from cam covers and inlet to a catch can with a filter on it but I always wondered whether the compressed air would escape from the inlet manifold

[lolwat]

if its a cut and shut mani NO, as it get blocked

[killapotatoe]

Hi FAST EDDIE,

do you happen to have a picture or a drawing of how this might look down?

Thanks a lot :)


if ur going to run lots of boost you NEEd to have a breather on both rocker covers and you need to have a big breather (bigger thatn the std one)or it will just overfill the rockercovers with oil and spew it out the breather, ive also done the aim it straight out to the ground but this was in a street car with 12psi so never got too much of a hard time!

[FAST EDDIE]

cant find a pic of i anywhere
The correct way to do it would be to weld some at least 15mm outlets on the top of the cam covers (20-25mm better) and run em to the catch can. ive blown a motor pumping all teh oil out the breather to the catch can and loosing oil pressure, that was limiter bashing a lap drifting, doesnt take long for the engine to breath out all you oil and the cam covers fill up very quickly.

The ca guys aer running 2 external oil drains from the rocker covers back to the sump as well as breather to the catch can also rb guys doing the same!

if you are going to be running higher boost on teh track this is the way to do it but for just general street duties and a bit of track driving its not realy required!

you could even drill and tap the existing hole to accept a bigger fitting which will help!

the inlet needs to have that breather hole blocked up because it will leak boost!

[FAST EDDIE]

this is an rb but you get the idea

[DR86FT]

this is an rb but you get the idea

What about the baffle on the intake side on a 4ag. If you put fittings on both sides do u need check valves like the sr20?

[Hen may possibly be a nut]

You should plumb your crank case vent line in before the throttle if NA or before the turbo if turboed. Don't screw around with a one way valve or any junk like that. Stock 4AGE intake manifolds look like the crank case vent is routed post-throttle, but it's actually an internal passage that runs out to before the throttle. This means that most cut and shut RWD manifolds have blocked this passage and you need to find another spot to run your hose.

I added an extra vent line to the top of the exhaust side cam cover and found this caused lots of oil in my catch can. Some baffling underneath this extra vent and the problem disappeared.

[R&D Mechanical]

Got pics hen?

[Hen may possibly be a nut]

Err.... no. And I'm 10,000km away from the car for the next few years so I can't take any.

I simply took about a 30mm length of some 50x50 square alloy tubing, cut a matching hole in the top of the cam cover, welded the tube to the cam cover then weld a cap on the end of the tub. And then I whacked in a fitting so I could have a hose running out of the newly made tower. Not hugely pretty. May not even hugely beneficial, but it was fun to make.