02SOMLS1WS6

I searched and can not find a thread that showed a nice catch can set up geared towards FI. I dont entirely remember the details but was a single can design that had routing that helped with the problem when no boost is present and also a routing to help the problem when under boost.

Can anyone help and let me know what you guys are using for a boosted set up. Pictures would be great.

Sweet_SS

I'm using an Moroso Oil separator. Pulling from bank #1 to on side of the can. From the other side of the can to the intake, with a "t" fitting for a line back to the turbo inlet. There are a total of two check valves in place. Using a breather filter on Bank #2.
This is the only pic I have. If you want more let me know, and I can take a few more photos for you after work. This is just another idea for ya.

XtremeDime

iTrader: (16)

Im doing a crankcase evac this year. Going to be using the exhaust to draw vacuum on the crankcase. No cans, no oil to drain anywhere.

Sweet_SS

Be careful. I was told this type of setup, would ruin a street motor...boost would be pulled past the rings causing oil to be evacuated out. I was going with the same setup as you until I heard this. Again, that's what was told to me anyways.

XtremeDime

iTrader: (16)

Umm...what?

Sweet_SS

I was told that the exhaust would constantly be pulling vacuum from the motor. Causing boost to be pulled through the piston rings at WOT. Supposedly the motor needs to be at atmospheric pressure to work efficiently...pulling and adding fresh air (i.e turbo inlet etc). Using the exhaust as a method for pulling crankcase pressure is a bad idea on a street motor. Again, that's what was said to me. My last car, I only used a breather can with -12AN fittings and called it a day...didn't pop out the dipstick, but the head lifted a few times. But it was a 4 cylinder motor.

PS - I'm still trying to wrap my head around this stuff.

Denali08

Can u explain why a catch can is needed for FI?

What's wrong with stock PCV system with FI?

Sweet_SS

Boost creates crankcase pressure....pressure around the piston and rings. The stock pcv system isn't efficient enough to release this pressure. On a NA motor, that isn't FI the pressure is solely on top of the piston, whereas with FI, it's on top, around and below the piston. This is why you see guys popping out dipsticks and blowing out timing seals. Without some type of ventilation, there's only one place for the pressure to go...outward through the seals. I am speaking from experience here. I was blowing out my dipstick on my last car with the stock PCV setup until I did the catch can method.

02SOMLS1WS6

Keep the designs coming with pictures if possible. Does anyone have a catch can design that is specifically for boost set ups? I wish I could find that thread but struck out. That can example must be in a thread of different topic.

Sweet_SS

Examples with Diagrams/Pics

https://ls1tech.com/forums/forced-in...-engine-6.html


https://ls1tech.com/forums/forced-in...rs-inside.html

Denali08

Thanks for explaining. So, the catch can will connect between passinger valve cover and Throttle body? Why is the tee back to the turbo inlet?

XtremeDime

iTrader: (16)

The exhaust doesnt constantly pull vacuum from the motor, at idle it pulls hardly any. As you raise the RPM the exhaust pulls more vacuum but the crankcase creates more pressure as well. Even at high RPMs this vacuum is only a few inches. Plenty of people run vacuum pumps that pull far more vacuum without an issue.

Saying boost was pulling was the confusing part to me....

The reason people blow oil out of their dipsticks and blow rings is because they keep a stock PCV style system on their motor and they literally shove boost into their motor from the intake manifold. It has nothing to do with FI creating pressure "on top, around and below."

ramairetransam

iTrader: (18)

this has me wondering , i just procharged my 99 formula , would just a breather on the valve cover help .?

Also if i did a catch can does anyone have one totally nice and instructions and very nice looking for about 100 bucks ?

Sweet_SS

That's not entirely true. Pressure does build up in the bottom of the block...creating cylinder pressure thus issues with seals and dipstick. This is why the dipstick pops out?

JAX04

iTrader: (17)

Yes, but a STOCK system has no way of stopping the Boost from going into the valley cover via the vacuum line between teh manifold and valley,


If you put a checkvalve their, then yes. But ideally, with a setup like that, you have no way of pulling vacuum when WOT with boost.

JAX04

iTrader: (17)

so....

You need to add a secondary vacuum source, IE, turbo/blower inlet, vacuum pump, or exhaust evac to take over after that valve closes from boost.

Sorry for split posts...

i used a T in that manifold to valley line after the check valve, so that i ALWAYS have vacuum pulled on the valley

Sweet_SS

Exactly. I'm using two check valves...one of which is connected to a line from the turbo linlet pipe. Great discussion, this is how people learn

XtremeDime

iTrader: (16)

Maybe I was just confused by your original statement. Pressure builds up in any motor, not just a boosted motor. Boost should not be leaking past the rings and pressurizing the crankcase ever. Unless you have fried a ring. If you have an improper PCV system this can happen on any motor.

I was more concerned with your original statement, you made it sound like the evac had so much vacuum it was somehow sucking air from the cylinder down into the crankcase.

Sweet_SS

That's how the guy made it sound to me I was confused too, but I just did it a different way. You'll have to post up pics when you complete your evac system.

XtremeDime

iTrader: (16)

Im doing it similar to JAX just with less hoses :p. Im going to run a line from the front of the passenger valve cover to the intake manifold with a check valve. The 2 other ports; driver valve cover and rear facing passenger valve cover, are going to be T-ed(or maybe each with their own) and evaced in the down pipe near my firewall.