Valve Cover AN fitting install for catch can

[Silver 95 GST]

Hi,

I'm building a lot of crank case pressure and want to install -10 AN lines fromthe vc to a catch can as can be seen in the picture. My questions is: Can this be done without actual welding of the fittings to the vc? Can they just be threaded in? Would lock tite or JB weld hold up otherwise?

Thanks in advance!

 

[habitatguy187]

I never heard that you shouldn't run without a pcv. Can you post some threads if it's been beaten to death?

When I run a PCV I get idle surge so I don't run one. ANyone know why that is?

Probably because you're pulling in so much extra fuel from the crankcase

Seriously though, idk why it would cause idle surge, but you need to hook it back up, the gas fumes supposedly break down the oil which leads to bad things . After you hook it back up mess with your BISS screw and see if you can get rid of the surge.

 

[Silver 95 GST]

Probably because you're pulling in so much extra fuel from the crankcase

Seriously though, idk why it would cause idle surge, but you need to hook it back up, the gas fumes supposedly break down the oil which leads to bad things . After you hook it back up mess with your BISS screw and see if you can get rid of the surge.

Thanks for the input. But with my pcv hooked up and the biss all the way in I get high idle/surge. So that's why I want to install a hella crank case ventilation system. I'm going togo with -8 fittings on the cover to some Home Depot Racing catch cans (water separators).

 

[Calan]

Can you post some threads if it's been beaten to death?

If you are of age, pop open a beer or 10 and read the stupid PCV question thread for starters. If not, get a couple gallons of your favorite non-alcoholic beverage and set aside a few hours for reading.

Here's some bullet points:

1. Home Depot catch cans don't work in the long run. The bowls are polycarbonate, and about 10 natural enemies of polycarbonate live in our engine bays. They will eventually break down and crack/leak.

2. There are two and only two (count them... 2) "correct" ways to hook up a PCV system on turbo DSM's. One is a modified/improved version of the stock system which works to both relieve CC pressure and ventilate the CC to prevent oil contamination, and the other relieves CC pressure but does nothing to keep your oil in good shape...which is fine for race cars or DD's that have their oil changed or analyzed every thousand miles or so. If you have a true DD that gets it's oil changed every 3-5k, you need a PCV valve setup.

3. If you run a GM-MAF in a blow-through configuration, the ideal "modified" stock setup will cause fuel trim issues while in closed loop mode due to unmetered air entering through the VC. For most people it is a non-issue and can be tuned out (ignored)...but it is still an issue to be considered.

 

[No_Skillz]

If you are of age, pop open a beer or 10 and read the stupid PCV question thread for starters. If not, get a couple gallons of your favorite non-alcoholic beverage and set aside a few hours for reading.

Here's some bullet points:

1. Home Depot catch cans don't work in the long run. The bowls are polycarbonate, and about 10 natural enemies of polycarbonate live in our engine bays. They will eventually break down and crack/leak.

2. There are two and only two (count them... 2) "correct" ways to hook up a PCV system on turbo DSM's. One is a modified/improved version of the stock system which works to both relieve CC pressure and ventilate the CC to prevent oil contamination, and the other relieves CC pressure but does nothing to keep your oil in good shape...which is fine for race cars or DD's that get their oil changed or analyzed every couple of thousand miles. If you have a true DD that gets it's oil changed every 3-5k, you need a PCV valve setup.

3. If you run a GM-MAF in a blow-through configuration, the ideal "modified" stock setup will cause fuel trim issues while in closed loop mode due to unmetered air entering through the VC. For most people it is a non-issue and can be tuned out (ignored)...but it is still an issue to be considered.

I agree with all points above. However, before you reinstate your PCV system, find out why you are building such high levels of crankcase pressure. Having no PCV should make it easier.

 

[kicker91laser]

I have been wondering lately how well these would work when plumbed between the vc and intake pipe:

Moroso 85471 - Moroso Air/Oil Separator Tanks – SummitRacing.com

 

[Calan]

I agree with all points above. However, before you reinstate your PCV system, find out why you are building such high levels of crankcase pressure. Having no PCV should make it easier.

And I agree with that. ,

Very good point.

 

[Calan]

I have been wondering lately how well these would work when plumbed between the vc and intake pipe:

Moroso 85471 - Moroso Air/Oil Separator Tanks – SummitRacing.com

Before I get flamed for what I'm about to post, let me just state that this is solely just my opinion.

Catch cans are a topic that has been beaten to death within the PCV threads, but at the same time there isn't any definitve answer as to one that truly works as it should. Most CC's on the market are simply shiny cylinders with an inlet and outlet. The better ones work off the principal that pressurized air containing oil particulates will hit a baffle and the oil will separate and drop nicely into the bottom of a can.

The problem is that CC blowby contains a lot of oil aerosols that are made up of sub-micron particles, and commercial CC's don't have any mechanism to filter these particles...so you either end up with oil in the intake snorkel...or if you run with an atmospheric filter hanging off the CC instead of routing it back to the intake you eventually end up with a nice oil film coating your engine bay.

Long story short... just about any CC you buy will only remove a certain (relatively small?) percentage of the oil that is trapped in the air flowing out of your VC...so any well-built can with at least a baffle should work about as good as can be expected.

An opimized catch can would use a true coalescing filter with a low pressure drop to remove sub-micron aerosols, but as far as I know none are available...yet...but I'm working on it.

 

[Silver 95 GST]

I agree with all points above. However, before you reinstate your PCV system, find out why you are building such high levels of crankcase pressure. Having no PCV should make it easier.

Here's the situation. I've done dry compression tests and I get great results 170psi across the board. But I haven't done a wet compression t o see if it goes up.

So I think my rings, valves and valve seats are alright. If anything I think my valve stem seals are bad. When I pulled my exhaust manifold there was a little oil leaking through on the stems. So that might be where my crank case pressure is coming from because it leaks more when I boost.

But I want to see if I can fix my oil leak without pulling the head, because then I'll start thinking about a rebuild or new engine$$$$$$$$$$$.

So I've reattached my pcv with a us plastic checkvalve in line. I also put a check valve on my VC side breather. This way I'm not surging, but I think I still leak oil under boost.

SO do you think if I add a hella ventilation system I can get my crankcase pressure down?

Thanks again. I appreciate everyone's comments.

Thanks

 

[No_Skillz]

Here's the situation. I've done dry compression tests and I get great results 170psi across the board. But I haven't done a wet compression t o see if it goes up.

So I think my rings, valves and valve seats are alright. If anything I think my valve stem seals are bad. When I pulled my exhaust manifold there was a little oil leaking through on the stems. So that might be where my crank case pressure is coming from because it leaks more when I boost.

But I want to see if I can fix my oil leak without pulling the head, because then I'll start thinking about a rebuild or new engine$$$$$$$$$$$.

So I've reattached my pcv with a us plastic checkvalve in line. I also put a check valve on my VC side breather. This way I'm not surging, but I think I still leak oil under boost.

SO do you think if I add a hella ventilation system I can get my crankcase pressure down?

Thanks again. I appreciate everyone's comments.

Thanks

Side breather plus PCV will result in a huge vac leak in all sub-boost conditions. Checkvalve on the side breather is either pointless or cancels out the effects of the PCV depending on which direction it's attached. For more than you'll ever need to know about the PCV and ventilation system, click on some of the links provided. If you just want to hella vent, remove the PCV system altogether. Just keep in mind the drawbacks such as oil contamination.

I, like calan, am a proponent of the stock PCV system (albeit with upgrades) and suggest that you fix your seals and get the ventilation system back to spec.

 

[habitatguy187]

So I've reattached my pcv with a us plastic checkvalve in line. I also put a check valve on my VC side breather. This way I'm not surging, but I think I still leak oil under boost.

So you're pulling air out of the crankcase through pcv, and pushing air out the breather when under boost?

What happens when you can only pull a vacuum of 18psi out of the CC? With no fresh air coming in you'll put a vacuum in the CC, not sure if this will hurt anything or not.

Either way the side breather needs to be hooked up to the intake pipe, the mas already counts for air entering in and adds fuel for it, so if it's not hooked up, then you're going to run rich, making you slower.

Just hook it up right and stay out of boost until you either make a better breather system or fix the underlying problem.