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 Post subject: Re: oil catch can problem
PostPosted: Fri May 25, 2012 8:23 am 
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:-k I have a vented can on my injected 13b monsterport. Two lines connected, both going to the filler neck. It is mounted lower than the filler neck, so no drain. Also, only has provision for two lines, so how to pick up vacuum?? Or is it not a problem due to being n/a??

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 Post subject: Re: oil catch can problem
PostPosted: Fri May 25, 2012 1:21 pm 
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SIGHS

IN ENGLISH
the oil recovery system from rotors and from turbo is designed to work with gravity AND VACUUM from the outset ,, all the way back beyond 1970



rotors fill up with oil for cooling,, they fling it back down the centre plate,, its hot,, it has also picked up petrol fumes when recovered by the oil control rings

turbo is fed pressure from the top,, and gravities out the bottom \\\


scenario 1 --- ( the moron with open vents )
so you have pressure,, flows down to atmo ( if open vented ) ,, if the vent isnt big enough some slight pressurisation is happening because of the oil temp/ vapour pressure

this is acceptable in an NA engine ,, you can get away with it,, simply because the volumes of oil returning and the temps arent insane
/
on a turbo engine,, or one with hiflow oil pump,,or high internal oil temps different story
youve all seen the oil pushed out over the mazda font,,, signs the open vent is not coping the with the speed and volume of the airflow out the little vent outlet

OK ,, scenario one ---
x pressure flows to atmo ,, the pressure drop is X- atmo

,, the higher the pressure drop then the more the oil will return from the rotors and turbo without backing up
and forcing a new path across your oil control rings to the inlet side of engine ( which is under vacuum ) or via the rear turbo seals into the exhaust or compressor cover

scenario two ------- vents are sealed over\ sump space is over atmo pressure
so
pressure drop ( y ) = x ( pressure in rotors )- ( atmo + overpressure )
since the sump is sealed,, and its hot,, then that overpressure will skyrocket,, and cripple the flow of oil returning from the rotors and turbo
doesnt take much brains to work out this is not good,, and things will soon fail


scenario three
- a catch can
( sighs,, ok one set up with a breather ,, stop fucking asking the open ended questions and apply BRAINS to your individual can and the umpteen permutations of nipples and breathers )
set up as a mist seperator ( the correct term for its correct use )
, ie , the can is higher than the fill neck, the bottom of the can drains back to the lowest filler neck nipple , the other filler neck nipple hoes to the next highest nipple on the can,, and the highest nipple on the can routes to the air cleaner
( there ,,its not fucking hard is it ????? )

then pressure drop y= x- ( atmo - slight underpressure )
[ note the underpressure is very low , but is slightly below atmo,, due to the mini filter acting as a vacuum break ]


scenario four
as above ,, but catch can lacks the little air filter
pressure drop is y= x ( oil pressure in rotors ) - ( atmo - high underpressure )
[ this setup can induce a high vacuum in some setups and carry over if there is no can in between ]


out of all those,,( and i can think of about 4 other variations with other cans/ filters or lack of filter combinations ) scenario three and scenario four flow significantly more than others and can never back up with level or over pressure the sump,, even for a moment


right,, compare this to the FC stock system ,, with a passive purge control valve
under light load air flows FROM aircleaner , THROUGH the sump space and is consumed in the engine when its sucked in at the TB
heavy load,,, the one way valves and purge valves in the above system shut,,, and over pressure ( without a vac break ) flow in the reverse direction TO the aircleaner

if you observe what is happening you will see that the catch system ( the one hooked up right ,, that works ) can is mostly an emulation of the OEM full load scavenge path
variations ( umpteen possible ways you can make a catch can, good and bad ) will use the airbreak ( a small filter on can or on one of the filler point nipples with a one way valve preventing venting ), but flow towards the aircleaner



THERE IS NO PERFECT DIAGRAM THAT IS GOING TO SUIT EVERYBODY
dont blame me
i dont make all those non functional catch ( wank ) cans that sell but cant possibly work , and nobody follows the rule book,, and you cant expect a welder to actually THINK about what he is making

your buying them,, how about you THINK before you buy something with a nipple setup that can never work

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 Post subject: Re: oil catch can problem
PostPosted: Fri May 25, 2012 6:46 pm 
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bumpstart wrote:
Image

that is as simple as it can get , other method requires using the purge valve or purge solenoid and one way valves and then routing the vacuum to the TB instead of the air cleaner
( which will keep the turbo and the intercooler a little cleaner )


Bumpstart; What size hoses would be suitable for this setup ie vacuum, drain etc

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 Post subject: Re: oil catch can problem
PostPosted: Fri May 25, 2012 6:51 pm 
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your going to be stuck with same size as the filler neck nipples with most of it, however the vacuum hose can be as large as 3/8, but 5/16 is fine for most
you only have to get larger than this if you run very large boost or have a motor issue

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 Post subject: Re: oil catch can problem
PostPosted: Fri May 25, 2012 6:54 pm 
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Thanks bud ;o)

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 Post subject: Re: oil catch can problem
PostPosted: Fri May 25, 2012 8:38 pm 
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Cheers man. All clear. I shall begin making a setup next week.

Cheers for your time as usual :D

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 Post subject: Re: oil catch can problem
PostPosted: Mon Aug 12, 2013 1:14 pm 
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bumpstart wrote:
open venting works fine on NA stock engines,,but does not on anything with a turbo or high oil temps

i will say it loud and clear ( once again ) ,,,
sure -----------re-invent the wheel all you like with your catch can / extra sump / mist seperator
( depending on how much of an arse you made of the install )

but unless it has a vacuum on it , dont come on here wasting everybodies time asking why your engine puffs smoke and why your turbos and oil control seals dont last long
the answer is simple ,, cause you failed to hook up a vacuum, dont pass go, dont collect $200

BLOCKING THE VENTS OR LEAVING THEM OPEN VENT WITHOUT A VACUUM IS THE SINGLE BIGGEST RORT I HAVE SEEN DONE BY SHOPS AND INDIVIDUALS WHO SHOULD KNOW BETTER
it will invariably bring the customer back soon cause of smokey exhaust , and they scam a turbo, then an engine build out of it ,,, seen it umpteen times



Bumpstart you legend, I see you say atmo venting is fine for "stock NA" how about heavily ported racing engines?

I've always run atmo venting but I do have to regularly change oil as it gets quite contaminated. So a basic PCV setup into my LIM will draw all the fumes out? Massive overlap J port

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 Post subject: Re: oil catch can problem
PostPosted: Wed Aug 21, 2013 12:05 am 
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its illegal to have the filter on anyway..

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 Post subject: Re: oil catch can problem
PostPosted: Wed Aug 21, 2013 10:24 am 
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Post so I can find later.....

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 Post subject: Re: oil catch can problem
PostPosted: Wed Sep 18, 2013 10:57 pm 
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Hi guys, the more I read, the more I confuse myself. I want to set up the PCV version on my FC that Sir Bump has posted. I'm unclear on a few things with this set up.

Does the catch can need to be anything special, is it just an empty can or is it more complex? Also, wouldn't the air filter cause a vacuum leak and can it sit on top of the can, or does it need to sit on the upper side of the can? Can the PCV valve be any aftermarket version? and, where exactly does the vacuum line attach to intake, can I install a nipple on the compression tube?

The aftermarket cans that I've seen have two nipples on the top of the can and a drain on the bottom, can I modify one of these to work? Can I convert the drain plug to drain into the lower filler neck, use one of the upper nipples to the upper filler neck use the other upper nipple as a vacuum source? I not even sure what's in these can, the HKS version is listed as an oil separator. The nipples are marked in and out, not sure how what this mean in relation to a rotary engine.

Sorry guys, so many questions, so little knowledge.

Thanks in advance.


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 Post subject: Re: oil catch can problem
PostPosted: Wed Sep 18, 2013 11:48 pm 
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sighs..


unless you have a genuine PCV valve then dont bother ..and it is NOT a NRV and shaped to flow least at high vacs and is idle compensated when used with a carb
it is NOT the preferred option.. it is just out there,, cause it is,, cause some freaks insist in dragging out the hardest worst option

also

unless you have correctly setup the purge control valve,, also dont bother with that method

and..
if you dont like yellow stickers, dont have a can that has a vent on it.. full stop
\\

Image
Image

go with the method as described as the same as emulating the mazda high load path

.. that flows towards the aircleaner at all times from the top crank vent nipple
.. and has an air break .. via a NRV and a rocker cover filter through the bottom crank vent nipple

.. it is never a vac leak.. all airflow into the engine is still metered by MAF or MAP
.. the vent system also doesnt vent down after shutdown anywhere it didnt whislt stock..


and its an almost direct copy of ONE of the paths used on the FC onwards ..already legal
.. all you have done is delete the 'low load' shortcut that previously required the purge valve

if clever,, you upgrade all these nipples and hoses to 5/16 and then they will also handle crankcase flows typical on loose high boost engines

you put your can ... acting correctly as a knock out pot.. inline to the aircleaner
( you can also ignore the bit of the diagram that has the stock charcoal filter can teed into it if that no longer applies to you )

there is 50 variations and brands of catch can .. and there isnt a universal answer for everyone .. you need to grasp the primary idea and run with it

ie.. air flows through the little airfilter ,, past nrv ,, then through the crankspace
..out the highest point to the catch can.. in at the medium point ( or lowest point not including drain point ) .. then out the highest most centre top point on catchcan to the aircleaner
( factory has another little nrv here but its only really necessary on the rocker cover filter side in the single path system )

im sorry you may have// will anyway // bought a retarded can
.. they dont care about function .. or law.. they just have to sell.. up to you to work it out how it suits

PS
ones with drain have to be set high if you wish the drain to be plumbed back
FD engine block has location at rear on turboside that is handy for such purpose
.. else most drains will have to be shut and manually vented down to grade

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 Post subject: Re: oil catch can problem
PostPosted: Thu Sep 19, 2013 12:04 am 
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Thanks again Paul, is there a catch can you recommend? Can I pay you to make me one that will fit where the charcoal canister is? I don't know if catch cans have fancy internals or if they can be an empty can.

PS: Mate, please PM me your address, I want to send you a Dan Murphy's gift card so you can have a drink on me. You have helped me no end.


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 Post subject: Re: oil catch can problem
PostPosted: Thu Sep 19, 2013 12:12 am 
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Oh I see, you're saying I can use the standard charcoal canister, just put bigger nipples to suit higher boost? and set it up like the diagram you posted?


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 Post subject: Re: How to properly setup an oil catch can (Bumpstarts Guide)
PostPosted: Tue Sep 24, 2013 12:31 pm 
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standard charcoal canister is ONLY in the pic as some FC /FD users may still have it .. removing the charcoal can on the FC creates a fire hazard next to trailing coils

.. ignore it from the picture if it does not concern you

again.. i didnt draw the pic for your sake,, but for everyone.. take the info relevant only

it is NOT the catch can .. the catch can,, if installed would be inline between aircleaner and top vent nipple

only vent nipples from top vent to the aircleaner need to be upgraded to 5/16 for high HP boosted engines
on mine .. i have my top vent nipple threaded into the top of the cap,, it cant get any higher,, or easier than that
.. and i have LPG.. and zero lung mustard .. and a clean turbo
///so its very evident it works AOK ,, even without a catch can

can wise,, some have baffles,, some have an internal wire wool separator screen
,, some are simply an open can .. no i dont fab them .. i used to work with some fuck off big ones though

again its an entire discussion on random shit with umpteen variations that no-one bothered to stick a picture up of so im not willing to enter into any procrastination about

further prodding about random shitty catch cans without pic or link .. will only push my buttons,, think for yourself

you are buying it .. you work it out .,. if it doesnt have the right number of nipples.. in the right spots,, then dont buy it

its very clear we need at least one in.. one out ( via the top or via a filtered section ) and a drain .. and not much else besides maybe a wanky sight level

if it has a built on breather,, dont buy it..you cant get a one way valve in there to prevent venting after shut down ,,can you?

please use the intuition you was born with


PS
thanks for offer on dan murphy card but closest is 45 km away

..just treat yourself

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 Post subject: Re: oil catch can problem
PostPosted: Sun Oct 06, 2013 7:21 am 
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I've decided to go down the purge path and of course has lead to more dumb arse questions.
Bump, I was hoping you might be able to help me one last time on this topic please.

The factory vac diagram I have shows both lines going to the front of lower intake manifold (radiator side) Can I use the same ports with the purge set up?

The reason I ask is I can't find a port on the firewall side of throttle body, if there a port of the actual throttle body? or are you referring to a port on the back of the manifold?

I am going to run 20psi of boost, is the set up suitable for this boost level?

Also, can I run the filter off the catch can remotely to hide the filter. (off an extended pipe)
Thanks

Mate if you can't use a gift card, please PM me your banking details, I would dearly love to show gratitude for not only for myself, but for your contributions on this forum.


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