Here is how you install a catch can,

Discuss topics related to the CA18DE and CA18DET series engines.
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CA19DET
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Ok after postiong on Freshalloy and SXOC, i think i have cleared this up... here are the options for routing valve cover breathers, PCV and catch can..

here is the OE JDM breather system:



* the UK version has the intake and exhaust breathers connected by a 'T' fitting *

here are the options for installing a catch can..

this method retains the factory PCV and catches blow-by from the exhaust valve cover and allows filtered air to be vaccumed by the engine through the catch can breather filter..

this method too retains the OE PCV for the inlet cam-cover, but this time it draws filtered air for vaccum from the intake filter and any blow-by vapour would be returned to the engine after the AFM as measured air..

this method eliminates the PCV, so all blow-by vapour/oil goes to a catch can filtered by a breather filter on the catch can.



this si pretty much the same as the above version, except the intake and exhaust breathers go individually to the catch tank, eliminating the chance of over presurizing the valve covers incase of a blown ring or valveseat etc.. but some catch cans may need to be modified for a breather filter to be fitted..

of course on all versions, the rear inlet cam cover breather that goes to teh crank case (block) should be cleaned and or replaced with a stainless steel line or clear high temp hose so you can easily clean / remove it so you eliminate over presurizing the crankcase and causing blown out dip sticks, seals, oil-flow reversal, starvation etc...

now there are other versions where you can route the oil catch can to drain back to the crankcase, i have not included this version..

comments / corrections / additions of course welcomed,

archive if apporved by god.
Modified by CA19DET at 11:21 AM 9/27/2005


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float_6969
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I think CA19DET's MS Paint sklz > NeedCAforS13's.

Here is my concern about some of those setups.

Ideally, to remove the greatest quantity of crancase pressure, and more importantly, the corrosive gasses and moisture present in the crankcase, wouldn't you want the have the crancase under at least some sort of vaccuum under all conditions? With all of the diagrams using a breather, the crancase won't be under a vaccuum when it's under boost, which is when the most crancase pressure is present. Granted that with the breather in place, when the pressure exceeds atmospheric, it will exit the crancase, but it's got to exceed atmospheric.

Maybe it doesn't matter as much as I'm worried that it does. I'm contemplating using a small electric "blower" in combination with the catch can. Then the crankcase should be under constant vaccuum. That's also a lot of work too...

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CA19DET
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i understand your concerns as you have raised them now, BUT - i am currently running NO breather pipe on my intake, no filter nothing, its just there, and my engine is fine.. it doesnt have blow by on the intake, only slightly on the exhaust, and i have total seal rings and 160 across the board..

i dont know if maybe with it routed differently, it may help remove some of the blowby i have (though, i think its due to the Total Seal rings which take forever to seal properly..)

i have read of poor breather system set-up causing bad cylinder sealing because of crankcase presure..

So float_6969 what diagrams you think need adressing??
float_6969 wrote:I think CA19DET's MS Paint sklz > NeedCAforS13's.
MS Paint WTF is that??

Adobe all the way son, PhotoShop
Modified by CA19DET at 11:07 AM 9/27/2005

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biosehnsucht
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guides FTW!

I had a second oil return bung welded into my oilpan and I plan to use a Mazdaspeed Miata OEM catch can/oil seperator to return the oil to the pan, but otherwise work like a catch can. Think of it as a catch can that never fills!

But I haven't had the money to throw at it yet and I've not really had any problems w/ no catchcan at all, OEM setup ..

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float_6969
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There was a post a while back with all sorts of PCV diagrams on there, but I can't find it. My last picture on that post is how I would run it. It's the most complicated though, and would be greatly simplified if you could simply hook up some sort of small electric blower to apply negative pressure to the crankcase.

I apologize for the MS Paint comment. I stand corrected. And you're right PhotoShop > MS Paint!

I also have a problem with returning that oil to the oilpan. Part of the reason for removing it is because it contains A LOT of moisture and some possibly corrosive acids. Returning that oil to the pan seems to negate the whole point of having the can, except that you aren't feeding it back into the motor to have it burnt.

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biosehnsucht
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Hey it works for the OEM turbo'd Mazdaspeed Miata and those come with a warrenty on them, so I doubt they'd use it if it would be a problem before 30,000 miles

nismoplsr
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Instead of putting a breather filter on the top of the catch can, run a hose to the turbo inlet post MAF to get a suction. The oil should be caught in the can and the turbo would be sucking in clean air and creating negative boost in the crankcase.

Or put an angled bung in the exhaust to create a siphoning effect and burn the oil.

Coldspawn
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nismoplsr wrote:Or put an angled bung in the exhaust to create a siphoning effect and burn the oil.
There is the answer I was looking for.

When you have the turbo "suck" the vapors, you let oil into the cylinder. Oil has the octane of about 40. Unless you run a baffled catch can in line with a one way vavle.

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Coldspawn wrote:When you have the turbo "suck" the vapors, you let oil into the cylinder. Oil has the octane of about 40. Unless you run a baffled catch can in line with a one way vavle.
I should say run an oil seperator, which would be the catch can with baffles.

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CA19DET
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i wasnt going to run the oil vapour back to the engine preferably, i dont have a MAF so returning measured air to the intake isnt neccessary either, i jsut wanted to create a definitive post with diagrams that are easy to read for your application..

i dont want to mess with the OE drain system from the inlet cam cover, i think thats where people get into trouble,

you can also run twin catch cans for intake and exhaust, and i'll post the pics for that, jsut clearing up some issues on sxoc members..

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float_6969
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The twin catch can setup would be the easiest, and catch more oil, but finding room for two can kinda suck.

I personally don't like the idea of feeding any of that crap back into the motor at all, hence the small electric motor/fan idea...

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CA19DET
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float_6969 wrote:The twin catch can setup would be the easiest, and catch more oil, but finding room for two can kinda suck. I personally don't like the idea of feeding any of that crap back into the motor at all, hence the small electric motor/fan idea...
with a proper working system you shouldnt need the fan, i think leaving the catch can so it doesnt drain to the oil pan, and having the OE breather from the intake cam cover to the crank-case is best left alone, the other breathers can be messed around with once done correctly..

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float_6969
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I found the other post...zerothread?id=81100I think I'd use setup #4 IIRC

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shally2186
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so i read over this and the other link off of this and still havent decided which way i would like to go with this...

My plans are to Keep the CA18DET (RWD) in my S14 Stock..My only mod pretty much will be a SR T25 and Maybe a Nismo FPR.. im planning on running like 12PSI Tops and it will be more of a Daily Driver, but will be Drifted every once and awhile..

Have we decided on the BEST setup or is it like " To Each Their Own"?

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Just read that old thread on this. Float those drawings ought to be framed. PRICELESS!

They have got to be the classiest MSPaint drawings ever. I could not fathom it taking you more than 17 seconds to make any of them.

I would also like to point out that in THIS thread, #3 is incorrect. You cannot get positive pressure through the line you have attached to the inlet, right after the filter. It will only operate in a high-to-no vacuum state. I guess in that respect #1 is slightly misleading too. All that taken in to account, #3 seems like the way I would go.

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shally2186
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r34 gtr wrote:I would also like to point out that in THIS thread, #3 is incorrect. #3 seems like the way I would go.
Its incorrect But you choose it?

Will Do, ill read out the old thread..THANKS!

out of these pix, Which setup is the MOST efficient

#1

#2

#3

#4

Modified by shally2186 at 10:34 AM 1/25/2010
Modified by shally2186 at 10:35 AM 1/25/2010

bentvalves
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If the car is a street car and will be running low boost, catch cans filling up shouldnt be too much of an issue. If your tracking the car, or running high boost, or rev the piss out of your engine filling catch cans usually becomes an issue. I have my oil draining back into my oil pan as well via the turbo oil drain.



if you are truly having issues filling catch cans running high boost and would like another option rather than returning the oil to the pan (we change our oil often enough, it shouldnt be an issue ) the sr20det factory oil catch is your friend! It needs modifying, it will be a pain to install *engine out preferable* but this will put an end to your catch can filling days...



that keeps blowby OIL down in the case, but still allows the head and block to equalize/breathe.

my current setup draining back to pan atm, I dont have the SR catch tank installed under the intake manifold of this motor however. The PCV is now capped, and the exhaust valve cover is also breathing into the catch tank, which now has filter fitted to the top.




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shally2186
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well my car is mainly Street but will be drifted like once a month..Plans are to run about 12PSI of boost so im not going ballz out on it and high Rev'n may only happen alil in the heat of Drifting...

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Most of your blowby occurs when you're under boost. That being said, you'll stop the most blowby by installing the catchcan between the exhaust side valve cover and the turbo inlet.

Be aware that when you're under boost, and then let the throttle shut, that all of the PCV gasses and oils go directly into the intake manifold, and fresh air would normally be drawn into the head via the breather tube coming from the turbo inlet, but since you've installed a catch can, IDK if clean air is now entering the head, or dirty air from the catch can.

I don't have a MAFS, so mine is going to be routed like I posted on page 2 of the thread I linked.

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shally2186
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well i have a Maf and i kno they are always causing problems..

think im gonna go with this setup..My wifeys SR has hers the same way..the reason im try to def get this right is because ive learned from Friends CA's in the past squirting mad oil out if there isnt a catch can or filter..


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shally2186 wrote:
Its incorrect But you choose it?
It is not incorrectly routed, so the method is sound, but the "boost" arrows going away from the intake pipe would not actually be there. It would either be under vacuum, pulling air through the catch can and into the intake tube, or it would be at atmospheric pressure, and no air would be pulled through. You cannot really have positive pressure before the turbine, so the red "boost" arrows going away from the inlet pipe are misleading.

Does that clear it up?

I was under the impression that you needed to have a vacuum across the breathers, so that it pulled gases through and aided in ring sealing. Just venting a catch can to the atmosphere seems to defeat the purpose to me. It would be a sound method if you were running a naturally aspirated engine, but in one with positive manifold pressure you would want to actively pull air through the crankcase under boost, sort of. Am I wrong?

I don't claim to know everything. Someone set me straight.

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r34 gtr wrote:
It is not incorrectly routed, so the method is sound, but the "boost" arrows going away from the intake pipe would not actually be there. It would either be under vacuum, pulling air through the catch can and into the intake tube, or it would be at atmospheric pressure, and no air would be pulled through. You cannot really have positive pressure before the turbine, so the red "boost" arrows going away from the inlet pipe are misleading.

Does that clear it up?
oh yea..that def cleared that up

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Image

Been talking with some guys on Facebook (not sure if any are on here) and decided to share some info.

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sjbsuperman1425
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From what my brain can tell me, this might be the best possible catch can solution without modifying or dealing with the pipe that runs from above the oil filter from the block to the back lower of the intake cam valve cover. A "Tee" would be needed to be placed on the exhaust side valve cover to allow for the hose back to the intake tube and to the other catch can as well.

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You want as much NEGATIVE pressure (vacuum) in the crankcase as possible. Allowing the crankcase gasses to have to be forced out under pressure through the exhaust sided catch can means you have an excessive amount of blowby gasses building up in the crankcase. This is bad. The reason Nissan had the original setup the way they did was so that when you're in boost, the suction side of the turbo is SUCKING the gasses out, so that no pressure builds up. Here is the issue everyone has though. Once you replace the air filter and stock suction line, They're usually so un-restrictive that you don't create very much vacuum on that line, and the crankcase gasses build up. Venting to the atmosphere is only going to make that situation worse, plus it smells terrible. Ask me how I know.

It needs plumbed back into the suction side of the turbo. I would place the connection point as close to the turbo inlet as possible to get as much vacuum on that line as possible. As long as you have a catch can in place, no oil will enter the system and all you will be burning will be those stinky crankcase gasses.

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sjbsuperman1425
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That's what I always thought originally. I guess the long chat on The CA page on Facebook took its toll on my thinking machine. I had the same thought process as you Ryan.

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FB is bad for you. Stick to NICO, LOL

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sjbsuperman1425
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I think I actually made this post in here after I had already figured out that the diagram was a "no-no" lol My bad

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No worries, LOL.

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I have a drawing on my computer right now but I can't tell if it makes sense or not lol I'm trying to figure out how to draw in fresh air on idle, engine brake, partial throttle on the exhaust side cover and still filter out the "blow-by" when on boost.


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