Kfxguy

iTrader: (1)

Aight, me and a buddy were chatting earlier and I have him an update on my crankcase evac setup. He’s building a turbo trans am and he’s using me for info on some things. So the way I have it now is a 3/8” line to each valve cover and one 3/8 line to the lifter valley. They are plumbed into a catch can that has a big 3/4” line out the top of it and goes to the air filter side of the turbo, in the 4” silicon boot, right in front of the compressor inlet. Works good until the catch cam fills up with oil. My catch can is on the rather small side so if it collects 2-3oz of oil, it evidently sucks oil and will eventually start dripping out my air filter.


So. I had an idea of putting a small drain to let it just drain back into the engine. Before I even said anything about it, he said the same thing as I was telling him about it filling up with oil. So I wonder, why couldn’t I tap the bottom for like a 1/4” barb and plumb it into the timing cover to drain back in? I could put a check valve so oil would never be able to go back up. Is this a dumb idea? What are we not thinking about?

I know, just empty the catch can.....but I don’t always think about checking it. So if this would work, one less thing to worry with.

Old Geezer

iTrader: (3)

Why would you put nasty oil back into the engine?
Get a Mighty Mouse can, and be done with the mess.

ddnspider

iTrader: (26)

That stuff collecting in the can isn't just oil.

Forcefed86

iTrader: (4)

I'd say 90% of my catch can is water when I dump it. Also turns a nasty shade of foamy green if you have a leaky head gasket. Nice little warning sign.

The BallSS

iTrader: (9)

I've only ever gotten gasoline smelling water out of my Mighty Mouse PCV catch can, surely don't want that draining back into my oil.

Ping King

iTrader: (20)

Some have drained it back. I won't. You could also consider having a drain to a secondary can low mounted which will hold the funk until you're able to drain it at a regular interval.

Kfxguy

iTrader: (1)

Mine only has had oil with a very very tiny bit of condensation which naturally occurs in an engine anyways.

Kfxguy

iTrader: (1)

not this is not a bad idea!

AwesomeAuto

What happens when excess crank pressure blows directly into the bottom of the catch can, forcing it out the top and into your turbo? Better use a check valve.

Kfxguy

iTrader: (1)

Yea I had thought about that too. I'm just kicking around the idea. I just dont like the idea of having to drain the oil....just another thing for me to forget about....and forget...I will.


Checked this morning....no more oil dripping from the air filter since I drained the oil

ddnspider

iTrader: (26)

Breathers FTW.

Mavn

iTrader: (3)

I have 2 8an lines off each valve cover to a Breather Can that's big. works great

stevieturbo

It's a perfectly normal setup to return back to the oil pan ( return point should be below the level of oil, and ideally around 1/2" or so line ). Proper closed loop breather systems do it. Zero maintenance, zero problem, no oil loss etc.

**** that **** of emptying cans.

stevieturbo

A lot of condensation caught is because of the can itself. Like a cold alloy can remotely mounted.....it's always going to form condensation.

jordoza

Caterpillar and cummins have a system just like what Steve is talking about on there diesel engines. Works perfect. Never seen a single issue with that set up.

stevieturbo

It's very common, I've had mine like it for nearly 8 years.

An easy can to use for it is the Provent 200. I posted about it ages ago, and I see even LPE are now using it.

Diesel, but same idea

GMCGreg

FWIW , I found pictures online of gm's revised valve cover baffling which I basically copied to my 2004 valve covers. Without the ability to weld aluminum I just bonded little pieces of spare brake shim material in place with -the right stuff silicone. Basically blocking all the small lower holes except the drain near the hose barb , and shielding the large breathe hole from splashed oil. This reduced the amount of oil in my homemade catch can significantly -sorry no hard data on the amounts though. I get approx 3-4 Oz from 2 tanks of fuel , that could be 600 miles or a lot less depending on how much boosting. Also helps to build a catch can that can hold 8 Oz so that a 1000 mile trip doesn't require any maintenance. Actually hiway cruising accumulates less. As far as what's in the it just looks like dirtier oil than what's on the stick - Even if that's new

Forcefed86

iTrader: (4)

Put an elec vac pump on on your case and you'll be amazed at the crap that collects! lol. I eventually removed my setup, but it worked very well. It was a an electric smog pump. Filled up a standard 1/2 QT catch can pretty much every drive with sludge. I had mine triggered to activate at 1 psi. The issue I have with most breather style catch cans is they have no vac source on them. They should have large lines and pull vac to work well. It's a pain and most don't do it. (myself included) With a breather you might as well throw some SOS pads in a jar and call it good.

knickel

Yup Mighty Mouse