Redesigned Breather Setup

[daren_p]

The catch can I'm using is from JM Fab & is their small version. Their std version is with a vent filter but you can order it sealed, which is what I did. I actually think I found the best spot to mount it, which is on the front of the tranny where the bolt holes are from when you removed that stupied factory clutch resevoir thingy & replaced it with a SS line. Its tucked in out of the way from everything & it's right there if you need to empty it while doing your oil change. I can say there is zero oily build-up in my IC pipes that have been run for 2 summers.


PS Bruce, don't think I need to add anything on this subject, you & Romeen summed it up very nicely

PSS Romeen, I guess you are getting old


http://www.jmfabrications.com/catalog/product_info.php?cPath=22&products_id=37

 

[oldman]

Bruce you're going to kill me, but this is how I'm currently setup.

plugged PCV and filter breather on the VC. I can get a catch can, but I can't route back to the intake filter because my FP pipe isn't provisioned for it?

You're no longer allowed in my house.

We'll get all that fixed this season by adding a fitting on both your FP pipe and your JMF.

 

[daren_p]

Bruce you're going to kill me, but this is how I'm currently setup.

plugged PCV and filter breather on the VC. I can get a catch can, but I can't route back to the intake filter because my FP pipe isn't provisioned for it?

Thats a pretty week excuse , my FP intake has both the VC hose & charcol canaster conected

Drilled & tapped 2 1/4" NPT holes, got the required sized barb fittings, machined one of the barbs off the end to make them abit shorter & machined some of the threads of the other end so when I tightened them down, they fit nice & tight externally & are nice & flush internally. Installed them with Permatex high temp sealent. The nice thing about this is you get to pick where you want them installed, so mine are hidden underneath .

 

[drivemusicnow]

So, I understand the need for vacuum in the crankcase at all times (ie under boost as well as at idle), but my question comes to why the heck hasn't anybody mentioned a venturi exhaust vent?

I would think you would be able to run both lines to the same catch can, then run a silicone line down to the venturi effect nozzel that you woudl weld in your exhaust pipe. This would pull a vacuum, eliminate the hassle of dirty intake/intercooler ish, as well as let you monitor how much blowby your engine is producting (with the catch can).

I can't seem to find a link to a "kit" but it's a pretty simple setup. That is how I'm planning on running it unless someone has a strong arguement against it. (I'm always open to be proven wrong)

 

[oldman]

So, I understand the need for vacuum in the crankcase at all times (ie under boost as well as at idle), but my question comes to why the heck hasn't anybody mentioned a venturi exhaust vent?

I would think you would be able to run both lines to the same catch can, then run a silicone line down to the venturi effect nozzel that you woudl weld in your exhaust pipe. This would pull a vacuum, eliminate the hassle of dirty intake/intercooler ish, as well as let you monitor how much blowby your engine is producting (with the catch can).

I can't seem to find a link to a "kit" but it's a pretty simple setup. That is how I'm planning on running it unless someone has a strong arguement against it. (I'm always open to be proven wrong)

It will work as long as,

1. The check valve is located after your wideband sensor.

2. One of the two opening on the VC is open to atmosphere to supply fresh air for better ventilation.

3. Someone to test and amount of vacuum in the exhast system under different driving conditions.

With that said, with a total cost of less than $40 to properly run your stock PCV ventilation system while addressing all concerns, I don't think your setup would be cost effective enough in comparison.

 

[drivemusicnow]

It will work as long as,

1. The check valve is located after your wideband sensor.

2. One of the two opening on the VC is open to atmosphere to supply fresh air for better ventilation.

3. Someone to test and amount of vacuum in the exhast system under different driving conditions.

With that said, with a total cost of less than $40 to properly run your stock PCV ventilation system while addressing all concerns, I don't think your setup would be cost effective enough in comparison.

I would locate it right behind the engine which is about 2 feet behind my o2 sensor.

I am confused as to why you would want to keep the VC vent open to atmosphere? I would think that the vacuum created in the crankcase would be helpful. I understand the need to "vent" however the vacuum would, i think do a better job than routing it to the intake manifold or intake pipe would.

I would think a simple pressure/vacuum gauge mounted to the line under idle would check to see if there is enough vacuum to evacuate the crankcase at idle. I would ASSume that the vacuum created by the exhaust would increase faster than the increased blowby under boost/revs.

I guess the only real cost for me to do this would be one venturi pipe fitting that I could weld in place.

 

[oldman]

I am confused as to why you would want to keep the VC vent open to atmosphere?

To effectively ventilate, you need to supply the crankcase with a fresh air source, ever done a shutgun with a beer can?

 

[romeen]

ever done a shutgun with a beer can?

We have no idea what you are talking about!

 

[oldman]

We have no idea what you are talking about!

I figure you kids, especially calan, would be able to relate.

 

[Calan]

I figure you kids, especially calan, would be able to relate.

Hey... I just saw that...a year and a half later

While I do appreciate being called a "kid" (especially by Bruce), I have no idea what a "beer shotgun" is

Actually, I'm back for a reason. After all this time and reading countless more threads (and several months away from playing with my DSM) , I still haven't seen or come up with a good PCV solution for a GM MAF blow-through setup.

I'm getting too much unmetered air... At idle (800rpm), AirFlowPerRev is only around .15 and I'm at 33hz AF...which makes low LTFT unmanagable. It's also causing me grief during the transition to WOT...So I need to resolve the unmetered air issue for good.

I'm leaning towards a straight fitting off the VC to my catch can, another VC opening with a filter to atmosphere for ventilation, and a suction from the can to an exhaust scavaging setup or maybe even a small 12v pump of some type. The only other idea I've thought about is some type of vacuum switch to change the VC's fresh air source, depending on vac or boost.

I just can't think of any other way to use the "stock" (i.e. best) arrangement with a blow-through configuration.

Any other ideas that you guys have tucked away somewhere?

 

[VETTE_50_TH]

YOU CANT DO THIS!!! AHHHH. No, we beat this thread to death and there are only 15 posts worth reading.

James

 

[Calan]

James... yeah... but in all that DH beating, nobody has come up with a good blow-through solution yet

 

[dsm-onster]

I's called speed density