[Want2BS8ed]

When you use the 2nd catch for fresh air you can either plumb the inlet side ahead of the TB or Carb using the existing air filter or just put a filter on the catch can. Main thing you are trying to prevent is oil and oil vapors in the intake and TB. Most don't realize how much oil vapors get into the fresh air side to the TB. They happen after engine shutdown the hot gasses rise, cool, and puddle along the air intake track.

I like to see at least 3/8 inch so that it isn't restricted.

Let me make sure I understand, you are not installing an air/oil separator on the intake line to scrub ("catch") incoming PCV air, but to scrub only the back flow after engine shut down?

If that's the case, given these catch cans are directional, how are you orienting the inlet/outlet?

 

[Hillbilly Heaven]

For me, no, not really. For some, perhaps. On my 351 EFI intake, they brought the PCV hose around to the upper plenum to a second port near the main vacuum tree instead of on the back, near the #8 intake runner.

I’m actually doing this just to help prevent gunking up the intake with deposits. I figure the more I can prevent keeping that trash out of the intake and combustion chambers, the better. The PCV vacuum port on this intake is underneath the main chamber, to mix into all runners.

I would rather see that port on the valve cover hooked to fresh air. But you maybe ok as that port is not as far back as some valve covers. Definitely acatch can on that setup. I will get into the real reason why later.

 

[Hillbilly Heaven]

Let me make sure I understand, you are not installing an air/oil separator on the intake line to scrub ("catch") incoming PCV air, but to scrub only the back flow after engine shut down?

If that's the case, given these catch cans are directional, how are you orienting the inlet/outlet?

Yes you are correct. Will explain it later.

 

[Hillbilly Heaven]

Since everyone seems to like this idea, let me go into more detail. I will break it down into vacuum side and fresh air side. Also why you need both.
First off read and study this article. The diagrams will open to larger pics if you need to.

Blog Post Catch Cans 101

Ignore the section about the AOS (Air Oil Separator) it over complicates the project. What we are using is catch cans the separate out the oil differently.

What I will be discussing is the closed system, the diagram in the middle.

The vacuum side is the blue lines, Fresh air is the tan lines. No bikini here. Those running a carb can imagine the carb in place of the throttle body.

ok here we go. Whew I need more coffee.

You want the PCV connection In the farthest forward port of the valve cover. The reason why, is that acceleration forces the oil to the back of the cover and you will suck a lot of that oil into the separator causing increased oil consumption and frequent emptying of the catch can. The valve doesn't need to be in the valve cover but at least somewhere in the system from the valve cover and the vacuum port. The other line will run from the catch can to some point after the throttle body or carb. Now that you have captured the oil and oil vapor you will not have a dirty intake or intake ports in the head. Yes on some intakes this will help solve the dead #8.

Oil and oil vapor in the intake reduces the octane rating which does result in pre ignition and reduced power. You may not be able to hear the pre ignition but it is happening. Now that you have eliminated the oil and vapor you may find you can now run more timing. Like 2 to 4 degrees more. You might even gain a mile or two in gas milage.

Yes you do need a PCV valve. It regulates the vacuum. At idle and cruise it limits the amount of vacuum in the PCV system. It will keep you from sucking too much out of the system. Eliminating increased oil consumption and frequent emptying catch can. During acceleration you have low vacuum so it opens wider to allow more flow. It is hard to tell in this pic but the blue part of the PCV valve is tapered.

Ok let's get to the fresh air side of the system. You want a catch can on this side as well.. It IS NOT for filtering the air coming into the engine. Your engine air filter does that. When you shut down a hot engine you have hot oil vapor escaping the crankcase. If the PCV valve is working correctly it can't escape on that side, so it escapes on the fresh air side. As it cools the vapor condenses into a liquid. This liquid puddles in the section between the air cleaner and throttle body.

You carb guys aren't left out either. How many of you have removed the air cleaner lid and found oil puddled inside? This is where that comes from? Guess what happens when you start that engine. It gets sucked in the TB or carb and into the engine. NOT what we want. Remember we are trying to eliminate any oil or vapor reaching the engine.

You guys running a TB with coolant lines for preheating the air in cold conditions have another problem. That heating actually cooks the oil and turns it into carbon. How many of you removed the TB and seen it black inside or had a sticking throttle because of carbon buildup? Most say bypass the TB coolant lines. Yeah sure no more carbon deposits but that doesn't fix the problem. The problem is stopping that oil and vapor from coming from the engine after shut down. This is why you need the 2nd can.

For the question about reversing the connections on the fresh air side. In the system diagram above look at the top side of both cans. On the vacuum side air is flowing from the engine to the top of the can. On the fresh air side with the engine running, air flows from the engine air filter to the side of the can and out the top to the engine. On shut down the hot engine vapors enter the top, condense and fall into the can trapping the oil in the catch can keeping them from entering the air intake system. You want to connect both valve covers to the top of each catch can.

I like running valve cover breathers with a PCV valve built into them. I remove the valve on the fresh air one. It does mean that I have remove one of the breathers to add oil. I am trying to eliminate that by adding an oil filler neck on the fresh air side.

Cobra Valley's Billet Aluminum Breathers & PCV Housings

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I am considering adding this filler neck to the fresh air side. It is easy to plumb and the fresh air connects to the side of the filler neck. It does mean it is close to the firewall and may make it harder to add oil. You could put it on the vacuum side if you can figure out how to add a PCV valve somewhere on the vacuum system.

Trick Flow® Billet Oil Fill Kits TFS-51400800

www.trickflow.com

With the Radium or Racetronix catch cans they have -10AN O ring ports, you can use a Radium PCV valve mounted to side of the catch can, not the top. Pay attention to the arrow and the direction the air flows. You can get them barb for 3/8 hose or -6 AN.

10AN ORB PCV Valves

Billet 10AN ORB PCV Valves

www.radiumauto.com

I hope I haven't completely confused everyone. Pros of running this time of PCV system is it reduces oil consumption, prevents a dirty intake and intake track, improves engine performance by preventing oil and vapor from entering the engine. Cons are it involves more plumbing, take up more space, and requires occasional emptying of the catch cans.

I know I have talked mostly about Radium and Racetronix. What I am saying is not marketing hype but actual facts. There is no reason not to use the Moroso catch cans. I hate their term AOS. The term AOS comes from the early days when boosted guys ran pneumatic air oil separators before people like Moroso Radium and Racetronix started making them.

Any of these Moroso catch cans or their universal ones would be fine.

Moroso Ford

Ford

www.moroso.com

 

[BigBlue 94]

still not sure on why a catch can on the intake side though? I am running a carbed motor, soon to be a sniper EFI setup. can you clarify some on that point?

You only need one if the PCV inlet is located within the engine air intake. On the EFI engines, the PCV inlet is located in the filter box (or inlet tube for MAF) and can backpurge vapors into the intake. On my 94, the PCV inlet filter was always oily.

A carb or sniper with a traditional round air cleaner generally doesnt hook to the PCV at all. Some factory ones did, especially 80s fords, but most people ditch that for just a breather on the valve cover.

 

[Stevo440]

As @Hillbilly Heaven said about having 2 Catch cans 1 in the PCV valve line and 1 on the Fresh air side, he is correct that when the Engine is shut down some Crankcase fumes will make their way into the Throttle body then Intake manifold but the "Main" reason is for the Crankcase pressure under High load/Full throttle when the PCV valve is closed pushes all the Fumes into the Fresh air Intake side and it goes directly into the Throttle body and then the Intake manifold then right into the Cylinders. So the 2 Catch can would prevent this from happening and to answer your question @Want2BS8ed, the Inlet side always faces where the Oil and Fumes are coming from so the Outlet side always has the Cleaned air from the Catch can.
I learned a lot about this in the late 80's and early 90's with my involvement with Turbo Buicks and blowing oil out of the engine at all the weak points; Seals, Gaskets and wherever. The Turbo created so much positive pressure that I also use to install a Check valve in the PCV valve line to keep the Intake manifold boost pressure from over coming the PCV valve and leaking/blowing past it into the Crankcase creating excessive Crankcase pressure. I don't know if I ever shared this with anyone before back then but it definitely worked great and STOPPED all the Excessive Crankcase pressure which in turn STOPPED all the Multiple Oil leaks. It also stopped most of the oil getting into the Fresh air intake side.
In my previous post to this I questioned the need for a Filter on a Catch can well for the PCV valve side they are DEFINITLY NOT needed but for the 2nd Catch can in the Fresh air Intake side on a system where the Fresh air comes from a filter on the Valve cover or in other words an Open system then the Filter would DEFINITLY be NEEDED.

 

[Hillbilly Heaven]

You only need one if the PCV inlet is located within the engine air intake. On the EFI engines, the PCV inlet is located in the filter box (or inlet tube for MAF) and can backpurge vapors into the intake. On my 94, the PCV inlet filter was always oily.

A carb or sniper with a traditional round air cleaner generally doesnt hook to the PCV at all. Some factory ones did, especially 80s fords, but most people ditch that for just a breather on the valve cover.

Yes you are correct. On the fresh air side you don't need a catch can if you are venting with a seperate air filter. If you are getting your fresh air the the air box, inlet tube, or for you carb or Sniper guys inside the air cleaner housing. Just remember that filter and everything around it is going to get very oily. It is messy. This is why I would rather run two cans and get my fresh air from the air inlet side.

Also a check valve is not a PCV valve two different animals. Yes back in the days of the boosted Buicks it was common to put a check valve in series with the PCV valve to stop positive pressure from boosting crankcase pressure.

Nowadays us boosted guys just run giant puke tanks vented to fresh air. We run 50 pounds of boost and run two very large puke tanks. We drain them after every round and they still make an oily mess on the deck lid. We do an engine leak down every pass to pass to be sure the rings are in good shape. With that much boost it is impossible to prevent blow by. Most guys here do not know I am a machinist, engine builder and crew member on a PDRA Pro Boosted aka Pro Mod car also from time to time I work on Top Fuel and Funny Car stuff too.

 

[robbz28]

My intake was super nasty, I thought about changing the intake PCV to an exhaust Crankcase evac system. Just need to drill a hole downstream and angle it in, comes with a check valve in case you have a backfire or anything.

Sent from my iPhone using Tapatalk

 

[BigBlue 94]

Just remember that filter and everything around it is going to get very oily.

It does indeed. Its currently mounted to the factory PCV "puck" from under a SBF intake plenum. It puts the filter at a 90° angle, so i can see the "Power By Ford" on the valve cover.

Moving that to the rear, will make it even oilier.

Im now envisioning running brass hardline to the front hole, to a second catch can. I have bass elsewhere so it will match.

Are you the one who does a lot with super high performance fuel systems? Im just a "shade tree" machinist with 9 months of schooling and a medium sized lathe/mill at home, who sells house paint for a living.

 

[Hillbilly Heaven]

Are you the one who does a lot with super high performance fuel systems? Im just a "shade tree" machinist with 9 months of schooling and a medium sized lathe/mill at home, who sells house paint for a living.

Yes that is the main business side. Plus we have race teams that hire us as crew chief and crew members. On a race weekend we will crew several different race teams.
Here is a link to our car builder and the Vette in the pictures is the newest addition to the stable,

Andy McCoy Race Cars | Washington MO

Andy McCoy Race Cars, Washington. 20,894 likes · 3 talking about this · 128 were here. Andy McCoy Race Cars Professional race cars and components

www.facebook.com

 

[BigBlue 94]

That vette looks like it could be a Batmobile! Its awesome

 

[Want2BS8ed]

@Hillbilly Heaven and @Stevo440, thanks for the explanations. Slow on the uptake, but the pieces are fitting together now.

Bringing up the oily PCV filter in the filter box (and why @Steve440) was the ah-ha moment for me.

Who knew when I originally installed the can to solve my blow by problem that I was actually doing something right!!

Fortunately, there is plenty of room on the other side of the Moroso bracket to mount a second unit.

Again, appreciate your taking the time to dumb the conversation down to the lowest denominator... me!

 

[CreigN]

I haven’t posted any questions or topics before but just started contributing a couple of comments recently in other threads. However, I’ve read FSB extensively since we bought our Bronco in 2017.

This post was really an eye opener. I always noticed the heavy oil/grease buildup from the PCV hose but I just accepted it and kept cleaning everything down stream.

After looking into the broad price range of PCV catch cans, is there a difference in performance between ones that have a low micron filter versus the designs using stainless steel filtration media?

And the prices vary widely, from around $20 to well over $300. My 1989 Bronco 5.0L EFI is a semi-daily driver and occasional fishing and skiing trips, not heavy off road activities.

Some brands, like Moroso, also state that they are “Not legal for sale or use on pollution-controlled vehicles.” I’m in California and have to satisfy smog restrictions so that brand is not an option.

I know many times the members have stressed “You get what you pay for” but does the PCV catch can solution fall under this warning too? I’m very conscious of it when buying and installing mechanical and electrical parts.

So my question is about the media filtration system on the cans. Both the same relative performance? Or is one better than the other?

 

[BigBlue 94]

I haven’t posted any questions or topics before but just started contributing a couple of comments recently in other threads. However, I’ve read FSB extensively since we bought our Bronco in 2017.

This post was really an eye opener. I always noticed the heavy oil/grease buildup from the PCV hose but I just accepted it and kept cleaning everything down stream.

After looking into the broad price range of PCV catch cans, is there a difference in performance between ones that have a low micron filter versus the designs using stainless steel filtration media?

And the prices vary widely, from around $20 to well over $300. My 1989 Bronco 5.0L EFI is a semi-daily driver and occasional fishing and skiing trips, not heavy off road activities.

Some brands, like Moroso, also state that they are “Not legal for sale or use on pollution-controlled vehicles.” I’m in California and have to satisfy smog restrictions so that brand is not an option.

I know many times the members have stressed “You get what you pay for” but does the PCV catch can solution fall under this warning too? I’m very conscious of it when buying and installing mechanical and electrical parts.

So my question is about the media filtration system on the cans. Both the same relative performance? Or is one better than the other?

The catch can's purpose is not to filter the oil out, but rather separate it from the air and keep it separated.

I used a stainless steel wool scrubby from the kitchen cleaning department in mine.

 

[jermil01]

Spent some time reading through this thread and I definitely learned a lot about the importance of the PCV system and the catch can. Anyway, last week I had to pull my upper intake. My Bronco doesn't get driven a whole lot (which I need to do a better job of) so there was quite a bit of build up in the intake. When I flipped the intake over to clean it, a good bit of oil poured out of one of the runners. My PCV system comes off the rear of the passenger side valve cover and then into an elbow where it then goes around an up into one of the ports at the center of the intake. I'm thinking I'd benefit from putting a catch can in line somewhere, but curious where the best location would be. Thanks.

 

[OX1]

It depends.

Very limited use (and carbed, which is less sensitive to throttle plate particle accumulation), I don't bother with one.
High performance naturally aspirated, will use one can somewhere in line with PCV.
Forced induction, I eliminate PCV valve all together (and basically the stock type routing of PCV system).
I gut PCV and run two more lines off each valve cover. Gutted PCV line goes to first catch can, vavle cover
lines go to second catch can. Outlet of both cans goes to ground. For these usually limited use engines, I change oil
more often due to loss of PCV scavenging. I've had too many seals blown out, on engines not originally designed for boost.
(much easier to change oil more often, than to have to redo a rear main seal).

 

[CrazyBRONCOguy]

@jermil01 Keep PCV valve, add hose which goes from valve cover PCV to catch can, then back to intake. Basically you want to interupt the current PCV system with a catch can. Though if you get too crazy on the lengths you can get into a situation where it will not run hot enough to get rid of the condensate (Likely less of an issue since your in Florida) very real issue up Here where I am at

All the info in this thread is good stuff. If you have never used a catch can, you will likely be shocked how much they collect in the typical 3-5k mile oil change interval. If you use vehicle for TOW duty or hard use I would check/drain them more often

 

[jermil01]

@jermil01 Keep PCV valve, add hose which goes from valve cover PCV to catch can, then back to intake. Basically you want to interupt the current PCV system with a catch can. Though if you get too crazy on the lengths you can get into a situation where it will not run hot enough to get rid of the condensate (Likely less of an issue since your in Florida) very real issue up Here where I am at

All the info in this thread is good stuff. If you have never used a catch can, you will likely be shocked how much they collect in the typical 3-5k mile oil change interval. If you use vehicle for TOW duty or hard use I would check/drain them more often

Thanks @CrazyBRONCOguy, that's what I was planning to do, then I watched this video and the guy installed one inline from the next of the oil filler to the air intake hose. I know @Hillbilly Heaven said it wasn't a bad idea to have two. If I were going to start with one, seems it would make sense to go with the one from the PCV to the intake.

 

[CDA 455]

Thanks @CrazyBRONCOguy, that's what I was planning to do, then I watched this video and the guy installed one inline from the next of the oil filler to the air intake hose. I know @Hillbilly Heaven said it wasn't a bad idea to have two. If I were going to start with one, seems it would make sense to go with the one from the PCV to the intake.

Thanks for sharing the vid. 🍺

nOOB questions inbound:
1) As someone who is nursing a 259,500 mile engine/hoping it'll last 3 more years; would I benefit (enough) from installing these catch-cans?
2) If I do the install; will I see/hear/feel a difference right away?
3) Better mileage?
4) Is there a big-enough difference between the $20 to $30 ones and the $130+ ones?
a) That one in the vid is nice; everything needed to install in the Bronco, but it's $135.😬

5) Which is better/and or easier; an open system or closed system?

 

[paul rondelli]

My buddy Steevee

Been following him for a while.

I put one on my 1996. It makes me feel better about myself .... I haven't actually gotten any oil yet ..... but who really cares.

I would think any kind of boost would definitely require one ... or if your tired engine is letting oil by the rings ... but my 1996 is as tight as a drum.

I think the TB buildup is more from years and years of tiny little amounts of oil vapor .... not actual aerosol oil droplets getting past.

It's not like it is hurting anything.