jmuck

Alright I just finished redoing my catch can routing and what some of you guys opinions.

Stock LS6 with a YSi and making around 15lbs.

I have an Elite Eng. catch can.
Here's the routing:
Hose from valley cover nipple to top of can.
Hose from can's bottom nipple to nipple behind the t/body with a check valve in it.
Hose from driver's side valve cover nipple to "T" in hose that goes from valley cover to top of can.
Hose from oil filler cap to nipple on t/body.

Before I had the catch can set up like above except for this: No check valve and a breather on the oil fill cap and driver's side valve covers. The can was catching most any oil that was trying to be pushed into the intake and I had no smoke coming from the breathers. I just had the valve seals replaced today and it started smoking quite a bit through the breathers.

So I routed the hoses like I mentioned above just a bit ago. Am I going to run into crank case pressue issues? Before with the stock PCV system it was building way too much pressure and trying to puke oil out of the seals. I just want to make sure I'm not gonna start trying to puke oil again.

jmuck

Never mind. Just answered my question. Got about half way through a 2nd gear pull and lots of smoke.

corvette8189

cap the TB and Intake
run a hose from the valve covers and oil fill cap to a filter

jmuck

Yea, but even then I'll still have the vapors puffing out from under the hood or from wherever I route that hose and filter.


I'm thinking of putting a -10 fitting in each valve cover, -10 line to a catch can with a filter on top.

95wht6spd

How much power are you making on the stock short block?

Corvette-Chris

That's exactly what I have. I do have a little vapor, but it's simple and effective.

tlove32

Stock bottom end LS6? Not Forged? If so, you don't have to worry about a catch-can - you're rings are going to be toast very soon at 15psi. Heck - they're probably already toast

jmuck

Yes, a 60K stone stock long block with a cam.
It made 705 at 13lbs, haven't dyno'd it at 15lbs. Just did a compression check and its fine.

The smoke isn't an abnormal amount. I'm just **** about it and honestly sitting a stop light and watching that shiat roll out from under the hood makes it look like a heap.

I've got an idea up my sleeve to try. Should have all the parts here in a week or so and if anyone cares, I'll report back.

jmuck

Just b/c its making decent power doesn't mean its gonna pop at any second. A quality tune and the appropriate water/meth set up and she'll live a semi long life.

Chris Stewart

Pics are good. Here's my setup. I have an 03 LS6 with external PCV. There's a check valve inline, and I capped the TB/valve cover.

tlove32

My bone stock bottom end did the same thing....smoke at stop lights, dip stick being pushed out, etc.... This was with 8-9psi and only 10 degrees timing - it don't get anymore conservative than that.

#7 and #5 rings were toast..... They don't do very well with that kind of cylinder pressure.

I hope it all works out.....

dsmlights

maybe your issue was because your timing was too low, you do know that causes higher EGT which too high EGT will mess up motor as well.

jobberone

That much heat will scorch your pistons and damage the rings. And the timing isn't that low.

jmuck

I don't have issues with the dip stick pushing out. The smoking at lights is (was) coming from the breathers, which I fixed last night by rerouting the catch can and adding a 2nd vent to the valve cover.

Its not if the stock bottom end will go, but when.

tlove32

RockJustBelow

Nice setup

What kind of check valve and PCV do you have?

jmuck

Okay, so I lied.

Its back to its trying to puke oil when I really get on it. Made a 3rd gear pull this morning and it was fine up to 7k, when I went to grab 4th and nothing but smoke again. I'm thinking since it only did it when I went to shift, did the check valve closing cause it this go around?

WTF is going on and how can I stop this w/out having to worry about the breathers on the valve covers and the smoke coming out of them??

Here's the routing as of this morning:
DS Valve cover, pass valve cover nipple "T'd" into line coming from valley cover to top of catch can.

Bottom nipple of Elite can going to nipple on intake with a check valve in it.

Nipple on oil fill cap going to inlet of blower.

I was thinking of trying this.

Hook the DS valve cover line, the PASS side valve cover nipple and line from oil fill cap to hose going to the blower inlet. Leave the catch can routing as it is.

Thoughts, opinions?

Chris Stewart

Thanks, I got the check valve from Turbo Tech, that sucker was like $100. I'm not entirely sure I needed it, but it provides guaranteed seal during boost, where the stock PCV is possibly unreliable. I run a stock PCV for a 2003 LS6.

You know alot of people run 2 catch can circuits, one for the PCV, and another for the valve covers breathing to atmosphere. For me the breather oil cap does the job of one, and the PCV line is cleaned by the catch can. I would start with that idea in mind, then modify after you have something that works.

I wouldn't route anything to the blower inlet, chances are you're feeding oil into it. No sense in running 2 lines off the passenger side, as you mentioned the valve cover line and the oil cap. Ditch one and also cap the TB line. You never said what year LS6, because the 04 has a PCV built into the valley cover right. If you try following what I described above, you will not eat oil.

jmuck

Thanks for sticking with me Chris. Does your car have any vapors/smoke come out of the breathers at idle that is noticeable with the hood closed?

The car is an 02.

The line tying each side together is run into the air filter line and I have a small filter on the end of it(inside the filter) to catch any oil mist. This is a temporary set up while I try to figure out how much venting the car needs to cure this issue. I was using both on the pass side to see if that much venting would help.

My next step is this:

5/8 nipples on each valve cover. A nipple and one way check valve installed in each header collector and a 5/8 hose run to each valve cover. Old school trick that will hopefully help me cure this issue. If it doesn't. I'll just put breathers back on each valve cover and live with seeing the vapors come out from the hood at idle.

Chris Stewart

No vapor at idle, but had plenty under boost. On a dyno run I could see oil dancing on the outside edge of my oil cap breather. Ok, maybe use your air filter to vent the valve cover lines, but don't tie them into anything else. Is your PCV installed, and running thru the catch can?