Homemade Catch Can

[mycarhasposessedme]

Just putting together my catch can setup at the moment and dug up this old thread searching for what others have done.
I am using 2 catch cans.
The first can will be the main catch tank and is baffled etc and the second can is a compressor air line filter (like Lex is using) being used as a precaution.
Why not just Tee them together and use only one catch can you ask?
Well the problem with joining the 2 cam cover hoses together is that they have different functions.
In order for a closed PCV system to work in a forced induction or na motor you need to have manifold vacuum for low throttle conditions and venturi vacuum for high throttle conditions.
This is the way the system is designed to function from the factory.
Converting a NA PCV setup over to a forced induction setup is not hard and just requires a bit of thought.
If you only have the PCV from the intake manifold, then the only time you maintain negative pressure is under light loads (when you need it the least). Under high boost when the PCV valve is closed, you need to have a vacuum source from the intake tract before the turbo where there is a negative pressure.
The first can will collect most of the oil and sludge and keep oil residue out of the intake manifold.
The second can (compressor filter) keeps oil out of the turbo and intercooler as under high boost the PCV may leak and create positive pressure on the breather hose side which would draw out oil vapors from the valve cover into the turbo.
I don’t think I will catch much with the second can but I will use it anyway as a precaution.
The PCV valve also needs to be moved from the valve cover to the line from the intake manifold to the catch can, to prevent the catch can from becoming pressurized under boost.
Pretty sure what I have described here is what the 2JZ-GTE’s PCV setup utilizes from the factory just with the addition of the catch cans.
Below is my cheesy ms paint drawing of the setup I have described above.
Cheers.

 

[mycarhasposessedme]

Also, as I understand it, the air flow direction in the breather hose changes depending on the state of the engine.
When the inlet manifold sees vacum, air is drawn into the crankcase through the breather taking all of the nasties with it into the catch can and then on into the inlet.
This is most important on engine warm up, as condensation is forming in the crankcase and without a properly functioning closed PCV system it will mix with your oil and form sludge.
When the engine is on boost the PCV is closed and the flow of the breather reverses to supply pre turbo vacum to the crankcase.
Sorry if i'm kinda repeating myself but its late, i'm tired.
You guys get all this stuff anyways.
Cheers
Trev

 

[cribbj]

Trev, as I interpret the diagrams below, Toyota's scheme for the 2JZ was to sweep any blowby gas under the valve covers back into the engine, under all conditions. Either the intake manifold is "pulling" on the valve covers via the PCV under vacuum conditions, or the intake of the turbo is "pulling" from them via the open vent line under boost.

I found no mention in Toyota's literature about a secondary function of the PCV to allow fresh air into the crankcase. AFAIK, the PCV system's only function is to get blowby gases from the valve covers back into the manifold. And the only reason it has several modes of operation is so that it won't act like a huge vacuum leak to the motor under high vacuum conditions and cause a rough idle.

If you wanted to duplicate the 2JZ system, I'd guess you'd have to put a PCV valve on each valve cover as well as a vent line going to the turbo intakes, and then put your catch cans in those lines?

I'd probably try do this by teeing the two lines from the covers together and run that into a single catch can, with an output of the catch can going to a single PCV valve at the manifold. I'd then run a second line from the catch can back to the intake of a turbo. I just don't know if combining the two lines from the valve covers into a single line would provide sufficient flow for blowby, or if it would cause too much backpressure....

This has been a hotly debated topic due to the 2JZ-GTE's front main seal failures. Some owners, after multiple FMS failures, are even venting their dipstick tubes and claim this has helped.

 

[mycarhasposessedme]

Hi john, hows it going, thought what I wrote sounded a bit confusing.
What I was trying to say regarding the fresh air was that under manifold vacum fresh air is drawn into the crankcase via the breather tube to create a flow through air stream.
Which as I understand it is the function of the breather tube on any engine and shown on your diagram as an arrow with broken lines.
Without a breather tube the crankcase will be merely in vacum and not able to remove fumes.
As you know under boost the PCV valve is shut and is out of the equasion other than if its not sealing correctly.
In this situation flow through ventilation is not the goal, whats needed is to release any pressure build up via vacum.
Surely a leak will occur only when the air going into the sump is greater than the vacum supplied is able to remove, via either a pre turbo vacum or an additional vacum pump or both.
Having to vent the dipstick tube seem to me that something is wrong with the system somewhere, as in a leaking PCV valve that is not shutting correctly and allowing pressurised air into the sump, or the setup is not capable of coping with lots of blowby by from that particular engine.
Unfortunately any external venting is emmisions illegal in Aus and not an option.
Placing a PCV valve in the breather tube hose will cut off the air pathway for sump evacuation under inlet manifold vacum. or the other way it will prevent pre turbo vacum to the sump. Thats why no valve from the factory.
Teeing the two hoses together also removes the ability of the breather hose to function properly. Placing a pre turbo hose back to the catch tank will work to give vac under boost but it will not allow flow through ventilation under inlet manifold vacum, so at best the sump will be in vac but not able to remove fumes properly.
Thats if i am correctly understanding what you have said.
Great subject this, always very hotly discussed on the internet.
Cheers mate

 

[Toysrme]

From yor drawing.
You must install a 1 -way check valve going to the intake manifold vaccuum. Otherwise you'll pressurize the crankcase & drop the lief of the rings.



You want vaccuum from the manifold because the manifold has high vacuum. You want the check valve to close when the manifold is under boost to keep the pressure out of the crankcase.

 

[cribbj]

Trev, I've studied that PCV diagram closely, and as far as I can see, there's no fresh air intentionally intentionally being let into the crankcase from the PCV system. The way I'm interpreting Toyota's diagrams is that the crankcase is always under a higher pressure than the valve covers due to blowby. I don't see any dashed lines (fresh air) going into the crankcase, or circulating in the crankcase; I may have missed something however.

There are devices on the market (Krankvent and others) which claim to put the crankcase under a partial vacuum, which is also claimed to be a good thing, reducing pumping losses.

Toys, the PCV valve, located at the manifold, serves the function of the check valve.

 

[Toysrme]

Yes, but i've experianced many of them that leak -> alot.
I preffer spending the couple of dollars on a ball & spring check valve that'll seal without question.

 

[striker]

Mine doesn't leak and if it would Mr Heineken would have a problem,

it works very well. it's called a Paco Bottle and is made from hard aluminium alloy.

grtz Thomas

 

[cribbj]

That has to be the coolest catch can I've seen. If you swapped it for a Budweiser bottle, you could call it a "Redneck Catch Can". Maybe you still can - do you have Rednecks in Holland?

You Dutch boys are always rubbing the rest of the worlds' noses in it that you have the best beer. The Heineken in the US is maybe one level above goat p*ss - it is so different from the real stuff on the other side of the pond.

Even the Heineken here in Algeria is better than in the US. Still....I see people buying it by the mini-keg in the US and lapping it up. If only they knew how good it really is elsewhere......

Sorry for the O.T., but when I saw that Heineken catch can, I just got very thirsty..... Glad I have a few of those green cans in my minifridge here!

 

[striker]

Maybe you know the "Holland Heineken House" which is set-up at every "olympic games" I'm working there as a volunteer always, I did summer olympics in Athens and last year wintergames in Turin(torino)
We tried to visit the torino Bud-house last year in out HHH jackets but the bastard wouldn't let us in :lame: hahahaha our party was 100 times larger than the budhouse in terms of public so we didn;t care that much.

That's the place you need to go if you would like to have a taste of the Best heineken in the world, the factory in amsterdam has several grades, and premium event grade (very expensive stuff as appears) is Over the top in taste...... and hadache also btw.

Normaly I drink Grolsch always but hey that doesnt come in these nice alloy bottles.

Ahh next week we'll be at "Les 24 heures Du Le-Mans" talking about loads of beer....... :684:

Grtz Thomas

 

[cribbj]

I like the Groelsch too when I can get it. I had the great pleasure of seeing the Heineken brewery one time in the late 90's, and like most, I don't remember much about it, but had a really bad head the next day for a souvenir.

Take plenty of pics at Le Mans for those of us who can't go! I really hoped to be able to make the Goodwood FOS this year with some friends from the UK but am here in the desert until 30.06. Maybe I can get to the Revival at the end of August.

 

[striker]

Will do cribbj,

We just bought a Tamron 80-250 lens for the cannon, so if the peep-holes are still in the dunlopp bridge we should have some very nice action pictures of the cars thundering up the hill from the grandstands at the karting nord, and the pittlanes by night offcourse.

I'll also be getting my twin M45 chargers at le-mans, friends taking them from th uk for me.

anyway the weather looks pretty bad for thursday.... and my striker is not the most erhhmm watertight car on the planet so we're in for some wet feet.

ps sorry for the trhead highjack!

grtz Thomas

 

[Toysrme]

werd cribb. the only time i do any kind of beer is like... miller / coors lite piss water at a kegger i know im not walking away from so it doesn't matter.

otherwise i've completely given up on US beer. i stick almost exclusively to liquors.
besides... for the cost of a manly case of GOOD beer in the US. i could have bought:
1 gallon of 190proof moonshine
4 gallons of punch
1L bottle of sprite
assortid mix of oranges, tangerenes, tangeloes, lemons, limes
and thrown a party noone walks away from

or made some sangria, or the world's largest blue hawaiian.




beer + USA = amatures.
brandon does NOT party with the amatures!!!

 

[SC400TT]

Hey guys, Cribb, Trev, toys, Lex...I know I am dredging up an old thread here, but I am looking at the best place and height to mount my Greddy Catch cans and the best way to route the tubing and set this up. I actually have 2 catch cans, and am trying to determine if I really need both, or if I can use just one. I actually placed a block off plate where the stock Valve was on the intake. So I need to design this properly. Any thoughts and additional diagrams are most appreciated, as this continues to be a hotly debated issue on the Web.

Also, the Greddys are rather large in size, approximately 8" long by 3" across in na rectangular shape. does the height of the cans really matter? I have heard that the higher they sit, the better.

Thanks,

Ryan

 

[cribbj]

Hey Ryan, thought you'd dropped off the map, bud. Is that beast of yours running yet?

Here's what I plan to do for my breather setup:

1) Run a 3/8" (interior measurement) line from each valve cover to a catch can which will be more an air/oil separator than just a catch can (ie it would have some sort of demister pad in it.)

2) Run a 1/2" minimum line from the catch can to the air intake, probably just after the filter, but definitely where there will be negative pressure, not any positive pressure.

3) The catch can would also have a drain line with petcock where you could drain off the accumulated gunk periodically.

To me, this system would do nearly all that the PCV system tries to do, and do it better. Some would eliminate the 1/2" line from the catch can to the intake, and simply vent the top of the catch can with a little K&N filter, however I don't like smelling crankcase fumes in my garage.

I don't know that the height of a catch can would affect its performance at all.

 

[SC400TT]

Hello John. No, just real busy with my business...Due to the wobbly economy, I have put in a lot more time to make up for the loss in revenue and income I have experienced over the last 120 days...Good news is that it is paying off, and first quarter 09 will be a bang up quarter...I also got a nasty sinus infection that took me out of work for almost a week, and then we have the Thanksgiving holiday. So here I am, working on the last details and plans to finish this car up and hopefully crank it up with the newly built motor by Christmas Day...Would bew a great Christmas present...

Thanks for your thoughts on the Catch can. Pretty much what I was thinking of doing...I plan to remount one catch can in the area where the charcoal cannister was, and T off both lines to one line and connect it to the hose barb on the baffled side of the catch can, add a ball valve to drain off the oil as needed, and then either vent off the other fitting through a small filter, or run it in between the filter and the turbo on the intake side of the car. I think I will try the filter first, and see if there is any issue with smelly fumes. If not, I will leave it at that. My thought on running a tube to the intake is will there be any oil sucked up into the turbo? I cannot think this would be good for the turbo if so...

Thanks,

Ryan

Hey Ryan, thought you'd dropped off the map, bud. Is that beast of yours running yet?

Here's what I plan to do for my breather setup:

1) Run a 3/8" (interior measurement) line from each valve cover to a catch can which will be more an air/oil separator than just a catch can (ie it would have some sort of demister pad in it.)

2) Run a 1/2" minimum line from the catch can to the air intake, probably just after the filter, but definitely where there will be negative pressure, not any positive pressure.

3) The catch can would also have a drain line with petcock where you could drain off the accumulated gunk periodically.

To me, this system would do nearly all that the PCV system tries to do, and do it better. Some would eliminate the 1/2" line from the catch can to the intake, and simply vent the top of the catch can with a little K&N filter, however I don't like smelling crankcase fumes in my garage.

I don't know that the height of a catch can would affect its performance at all.

 

[cribbj]

My thought on running a tube to the intake is will there be any oil sucked up into the turbo? I cannot think this would be good for the turbo if so...

That line should either come out of the top of the catch can, or the next highest point. I may have to modify an existing catch can to get what I want, because I want it to be a true air/oil separator. To get that, I need the outlet to be higher than the inlet, and there needs to be a demister pad between them, the idea being that the oil mist entrains itself onto/into the demister, and what comes out of the outlet is cleaner/dryer crankcase fumes.

There was a story in Autoweek a few years back about an air/oil separator with demister that an Aussie company fabricated. It did exactly what I'm describing, but I don't think they're around anymore.

 

[XR8tt]

Mounting them low beside chassis rail helps, with 18" fall they work well..

Yes I have made my own using 3" alloy tube with two inlets one side with a divider and outlet on the other.. With some stainless steel scouring [dish washing] pads to act as filter/ oil receiver..
If your really pedantic you can weld a small 6mm pipe off dip stick for the oil return off the bottom of oil separator so there's no need to drain tank..Also prevents dip stick blowing out..
I find on blown motors.. The higher you can have the outlet off the cam covers the better, gravity works...

Check out some brake booster one way valves work o/k inline with PCV when higher boost is run.. Nissan and some G.M vehicles have them..

 

[Zuffen]

I just made my separator/breather from a KH Laser (Mazda 323) polution canister.

It separates in the middle with a few screws and has a 3/4" hose entering the top and running down a stand pipe to the middle of the canister.

I added an alloy panel between top and bottom with a few holes in it for the oil to drain through.

THe top has an 3/4" exit line and the top is filled with stainless scouring pads to take the oil out of suspension.

I can drain it via a hose on the bottom.

The 3/4" lines run from both cam covers and throug a T and into the can.

The outlet runs to the aircleaner before the filter.

I can provide a link via PM to the Autospeed page that I got it from if anyone is interested.

I'm not using any PCV valves as it isn't under a lot of vacuum (almost none) so the engine sucks up any vapours.

Total cost was $35.00.

 

[XR8tt]

Fit PCV between blower and throttle body...
You'll bet heaps of vacuum at idle..