no. you cannot merge or delete part of the pcv system and have it still be ok.

pcv system must always be clean air in one end of the engine (measured by the MAF if you have one) dirty air out to pcv valve, line from pcv valve to intake manifold. catch can could be before or after the pcv valve but there can only be one hose between valve and intake manifold

 

After reading through this thread and several others, it seems like there are more than one ways to route everything.

For a twin turbo set up, trying to make around 600-700rwhp, would this be an idea routing method using a standard/cheap catch can? Only difference is I would most likely try to Y the two rear ports together.

What issues could I have doing it this way or is it good?

 

that flows the same as the stock pcv system because

it is a closed can

it uses a stock size fresh air / vent to the turbo

it will catch dirty side pcv flow

it will not catch clean side pcv flow

in order to flow more than the stock system we need lines larger than the stock system or multiple pressure exit points

 

As far as it being a closed can, is that relating to air entering into the can or exiting out of it? I wanted a closed system in my mind because I didn't want to have to smell any oil vapors while driving.

I wasn't sure if a clean side catch was necessary? Does your single can set up do both clean/dirty sides or one only?

 

what i mean by closed can is that there is no alternate ventilation point other than the stock one

clean side catch cans are for when the first catch can you install does not do the whole job.

yes i like to see only one (good) can to cover all the bases

 

I am assuming your can with the filter on top solves that closed can issue, by allowing it another ventilation point to take in air from? Is that only for air to enter into the can and not exit it? Cause when I was looking at your cans, I actually wasn't sure if the filter was meant to allow air in, out, or both?

 

depends on the model, draft and pcv are pressure release only

 

From what I read on your site, the PCV seems like the set up to go with if I wanted to minimize oil smells. However, with the filter on top, at what pressure/psi does it open to vent out at?

 

it depends on if you are past what the stock pcv system can handle or how you want it to look as to if you need to go all the way to the pcv can. the pcv is the most flexible model for sure.

the breather or recirculator top open at 0psi see this.

 

I have an '01 LS1 block (non vented journals) that's built into a 383 stroker. professionally built engine, 4" crank, ported 243 heads, matched cam, etc. 553 flywheel hp. I have an RX catch can routed like the pic attached from this thread yet I'm still getting excessive crankcase pressure and it likes to blow out past the o-ring at the base of my dispstick tube.

1- I don't want to just add breathers as if I understand this correctly- it'll defeat the whole catch can assy and be an issue for track days.

2- currently the tubing is 3/8" size. I could make tubes bigger but it will still bottleneck at the throttle body and on my valley pan (I have installed an LS6 style valley pan) Would that even help?

3- I am considering adding a pressure relief valve in the system, perhaps between the valley pan and catch can itself. maybe a 5psi valve with a breather type filter at the end. Would this work?

The engine itself is good, runs strong with only 6k miles and doesn't otherwise burn or leak oil except from the excessive pressure blow outs. I've had 3 incidents now. 2 at track days, and once this weekend when I wasn't even getting on the engine- maybe 30% throttle around a right turn. I did see the oil pressure gauge go up past 80 (engine has the melling 10296 pump and I use castrol 20/50 VR1 racing oil per the engine builder) and then it blew out again.


Obviously I'm missing something or doing something wrong. Thoughts or suggestions? Thanks!

 

the issue is that you are using a 300hp pcv system on a 550hp engine. you would not use stock injectors, or stock tires.. time to move away from that stock pcv system.

for example this vid

 

The logic makes sense.

How does your kit work? I was looking on your website- that breather on top of the can for the 4th LS F body wild, is it an open breather? Or is it a one way exit only (pressure release valve)?

 

It's a 1 way breather. His can also has a built in PCV. I tried fabing up my own and in the end, I scrapped it and went with his setup. It's very nice and hands down the best catch can on the market.

No smell and does everything I want it to do.

 

Good to know, thanks!

 

Time to get my catch can routing done. I read up on some stuff, but it seems no body has the same set up as me. And im hoping we can figure something out without having to make any major changes.

First i didnt think there was this many openings, but man, these is a ton of ports lol

Pass Valve Cover
-1 nipple at rear of the cover, has a small breather filter on it.


Driver Valve Cover
-2 ports at the top near the injectors; Breather filter in place of oil fill cap.



LS6 Valley
- 1 port in the front

Throttle Body
-1 Port

Intake Manifold
-1 port off the driver side near TB
-1 port off the pass side near TB
-1 port of the rear under MAP sensor

Valley Cover, TB and Pass Intake port:


Rear Intake Port:


Driver side intake port:


Im just going to assume the port on the rear of the intake is the port for the check valve line that goes to the booster.

What i have in my mind is:

-"Loop" both driver side ports with a hose
-Cap the driveside port by the TB
-Cap the TB port
-Run the hose from LS6 Cover, To catch can, then to passenger port near TB on intake.



Thoughts & Revisions?

 

@micbegz28 - what is your use for this engine? Race only? Do you want positive crankcase ventilation (ie vacuum applied) like a street car? Are you in a state where this car needs to pass an emissions check?

If I read your plan right, I think it's going to cause huge problems.

You are correct that one of the rear intake manifold ports on the back is for the brake booster.

The port on the throttle body itself is for clean air to go into the crankcase. I consider it "high pressure" for simplicity sake (but that's not actually true, it just makes it easy to think about).

You have breather filters on both valve covers and those are going to release crankcase pressure right out to the engine bay/atmosphere. They will also allow air in if there is a vacuum applied, and this will be a problem also. If you want PCV, you'll have to put solid caps on these positions or do something else, see below.

For PCV, you need a "closed" system. Air can not escape out of the crankcase on it own. Some clean air from the thottle body goes into the crank case and then the intake manifold vacuum draws the same amount back out, so the MAF does not lose or gain any air from unmetered sources.

What you proposed (I think) seems to maybe pull some crankcase air, but because of the valve cover breathers, you'll be pulling outside air into the engine, and into the intake manifold, but the MAF hasn't seen it. It's like a huge intake vacuum leak, or running at WOT even with the throttle close.

If you don't want PCV, you can leave the breathers, and also put caps on all the other locations too, and you're done. You don't need a can.

If you do want PCV, I'd suggest:
-Run a hose from silver thottle body tube to one of the barbs on the driver side valve cover. This "clean air" supply will push air into the crankcase. (Not really push, but for simplicity sake)
-Run a hose from the other driver side valve cover hose to the passenger side valve cover. Remove the breather and get an L fitting thing to stick into the hole like stock engines have. This also allows some air to circulate to the passenger valve side.
-Run a hose from the LS6 valley cover tube to the "intake" side of your catch can. The LS6 valley cover has its own oil separator built in and will help remove some oil from the air. Do not use this as an air input area.
-Run a hose from the catch can "output" to one of the ports on the intake manifold right behind the throttle body. This is your vacuum source which "pulls" air out of the crankcase, through the can.
-Put a plug on the other intake manifold port behind the throttle body. Stock LS1/6 manifolds only have 1 port, yours has 2 for some reason.
-Remove the breather filter from the driver side oil fill hole and put a normal oil cap that seals all the way.
-Put brake booster hose on back of intake manifold.

For times when your crankcase pressurizes and the intake manifold vacuum is zero, use a MightyMouse can, which has a pop-off valve so you don't explode your engine.

If your car is going to be turbocharged or supercharged, forget everything I said and talk with MightyMouse directly, you have special needs.

If anything I said is completely incorrect, MM please correct me. I'm confident I understand PCV pretty well, I've had to learn this when I redid my PCV and did the EGR delete on my car.

 

Not daily driven, but itll see some miles. Drive to the track, drive to work on nice days, some meets, ect.

Not really concerned with emissions/inspection.

Thank you for taking your time to write all that up! Ive never really set up a catch can set up on anything that wasnt stock so this is all new to me and you seemed to have really shed some light on it. Thank you !

No boost on the application. And obviously for a street driven set up im going to want PCV.

Looks like im gunna have to ditch the cool looking breather set up

 

If i do the following method.

-Run a hose from silver thottle body tube to one of the barbs on the driver side valve cover. This "clean air" supply will push air into the crankcase.

-Run a hose from the other driver side valve cover hose to the passenger side valve cover.

-Run a hose from the LS6 valley cover tube to the "intake" side of your catch can.

-Run a hose from the catch can "output" to one of the ports on the intake manifold right behind the throttle body.

-Put a plug on the other intake manifold port behind the throttle body.

-Remove the breather filter from the driver side oil fill hole and put a normal oil cap that seals all the way.

-Put brake booster hose on back of intake manifold.

Would i be able to run a MM PCV catch can with the vent filter set up? or would the MM PCV combine with the LS6 Valley be to much?

 

Are you running a MAF...?

 

Yes sir