Oil Catch Can

[Ceejay29]

How come some catch cans have a filter screwed to the top and others do not? And which kit (apart from ARC as they are a rare as rocking horse and super expensive) would you recommend?

 

 

 

 

 

 

 

 

 

 

[OllyB]

The air filter acts as the breather so all fumes are exhausted through this, you only want the breather filter on the non pcv valve side of the breather as this needs the vacuum from the inlet manifold to work.

[GMballistic]

This is what I have and a fair few others on here; http://www.350z-uk.com/topic/58175-oil-catch-can-tested-and-proven/

I went for it purely for the size of it as going FI means there isn't a lot of space to play with in the engine bay.

 

ChrisB has gone for the Mishimoto oil catch can ~ pretty expensive but looks so darn good. More info in his build thread here; http://www.350z-uk.com/topic/86592-precious-to-get-a-supercharger/

 

Also worth a read of this thread for info on the PCV system, post number 14; http://www.350z-uk.com/topic/82588-vortech-supecharging-technical-and-reliability-thread/

[OllyB]

This is what I have and a fair few others on here; http://www.350z-uk.com/topic/58175-oil-catch-can-tested-and-proven/

I went for it purely for the size of it as going FI means there isn't a lot of space to play with in the engine bay.

 

ChrisB has gone for the Mishimoto oil catch can ~ pretty expensive but looks so darn good. More info in his build thread here; http://www.350z-uk.com/topic/86592-precious-to-get-a-supercharger/

 

Also worth a read of this thread for info on the PCV system, post number 14; http://www.350z-uk.com/topic/82588-vortech-supecharging-technical-and-reliability-thread/

 

+1

The thread above is defiantly worth a read

[Ceejay29]

Cheers GM, just sitting down with a brew now. Thanks

[GMballistic]

No probs.

[Ceejay29]

Very technical!

[Tricky-Ricky]

Not quite sure i would agree with some of the recommendation's in that thread, the idle/low throttle side of the PCV system (the one with the one way valve)can be junked in most cases when going FI, as all it does is to draw a lot of oil vapor into the plenum (due to the very high vacuum generated at idle/low throttle) and pool oil in the low points of the plenum and then burn it on the first large throttle opening, not good on FI as it can lead to a sudden lowering of fuel octane due to excess hydrocarbons from the burnt oil, which can result in det.

 

The same happens with the N/A but its a somewhat lesser lesser risk as there is no boost pressure to add to the equation, so less chance of det, but still not desirable, which is why most people go for fitting a sealed catch can to this side of the PCV system to help eliminate the oil.

 

Its still desirable/beneficial to utelise the PCV system as it helps with ring/bore seal and to a smaller existent with stopping oil seal weep because its causes a slight vacuum in the crankcase,

 

The other side of the PCV system is the high load/full throttle side which is much more effective in helping with ring/bore seal etc when going FI as rather than as suggested be allowed to be vented to atmospheric air, it should be plumbed back into the turbo/supercharger intake which provides a good vacuum effect, obviously via a catch can to prevent extra oil contamination.

[dajw]

Hello! Newbie to the forum here!

 

I would like to learn more about crankcase ventilation with FI. I've got the Stillen / Vortech V3 setup. Trent Noller at Stillen told me today "Better crankcase ventilation will always help but it isn’t necessary with our kit."

 

The thing is, I consider me car a keeper, so I'm keen on things that aid reliability/longevity as well as the usual go faster mods!

 

Does anyone have any further recommendations on PCV, oil catch cans etc?

 

(I've searched and read the earlier referenced post too)

 

Cheers!

Edited September 3, 2014 by dajw

[Tricky-Ricky]

If it helps here is a little write up with a link that i did for the Skyline forum to help with explaining how PCV systems work, and how to use a catch can to the best advantage, you can safely apply this to a supercharger setup as well.

 

Catch Tanks, & PCV Systems.

I felt the need to write this up due to people thinking that there is only the one way to plumb in and use a catch tank, first it may help some to have a read of this,

http://www.autoshop101.com/forms/h63.pdf

which will explain the basics to those that don't already know.

 

Now the whole reason that a lot of people fit a catch tank is to try and eliminate some of the oil that gets drawn

into the intake system and not only lowers the octane rating of the fuel, (which is undesirable on turbocharged

engines) but also gum up throttle bodies, IC pipes and idle valves etc.

 

Now the PCV system of most turbo engines consists of a part throttle breather which has a one way valve that

is open during idle and off boost conditions, so the vacuum of the engine can draw any oil vapor thats formed

through engine motion and combustion, into the inlet and is burnt in the combustion process.

This valve is usually plumbed into the plenum, and is vented from the cam covers.

 

Now as soon as there is positive intake pressure (boost) this valve closes to prevent loss of pressure, and a second breather which is also from the cam cover and has no valve, takes over the breathing, but this is

plumbed into the intake before the turbo, so there is useually only a sufficient depression when there is boost pressure

being made.

 

Hopefully this will give you the general idea of it function, so when it comes to fitting a catch tank, most just

block off the non return valve into the plenum, and then fit an extension pipe to the full throttle breather to the

catch tank, and then leave the other opening vented to atmosphere, which is fine in most cases, and will

achieve the desired effect, however some engines do play up when using this form of venting, but it gets a bit

more involved than i want to go into here.

 

But there is a second way of achieving the same effect, but still using the factory PCV system with a catch tank,

This basically consists of linking both the full and part throttle breathers together, and running them to the catch tank, then linking the second hose from the tank back to the turbo inlet piping, so the same vacuum is applied through the tank to the cam covers when there is sufficient depression, but in this case the oil vapor is still re emulsified into the tank instead of getting drawn into the intake system, ( it helps to fill the catch tank with stainless scouring pads) to aid oil drop out, and with this method you will tend to see less water accumulation too.

 

So you see there is more than one way to plumb and use a catch tank.

 

There is also a way of using the exhaust as a PCV system, which i can go into if anyone is interested.

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[dajw]

If it helps here is a little write up with a link that i did for the Skyline forum to help with explaining how PCV systems work, and how to use a catch can to the best advantage, you can safely apply this to a supercharger setup as well.

…

 

Thanks Tricky. I'm interested in this. I still have to make a decision on what to do with PCV/OCC for my supercharged 370z, and I thrive on info so share away If you have any recommendations on what to install for my situation then I'm all ears too. I will prioritise elegant/practical functionality over needlessly shiny engine bays as this is not a show car.