Catch Can Advice :)

[jet2nv]

ok sweet as ill block off the PVC valve so should i just run that breather hose to no where lol or put a filter on it

[Rolls]

They don't breath enough air have a look at the outlet of the catch can , i bet it's smaller than one of the rocker outlets , they choke your motor to death.... Spend the money and do it right the first time

How will it choke your motor to death? It won't function very well but it won't cause any issue either.

no filter on the end of it sucking it i thought it vents out??

When your car is on vac eg idle and light cruise the PCV will be sucking air in via the catch can as you have blocked off the intake side. Can you draw a diagram of how you have hooked this all up? Do you have the PCV still attached?

The best way to set up a catch can is leave everything stock with the vent hooked up to the intake so that it sucks air out and the catch can just set up inline.

There is a DIY guide on here with pictures.

Edited January 9, 2012 by Rolls

[jet2nv]

yeah i followed a diy guide i just have

2 rocer breathers into a t-piece goin into one side of the can

then the 2 outlet on the can has a hose venting to atmo

and my pvc valve is still conected so i might block that hose off

[blind_elk]

It's really quite simple. There is a hose that runs from the LH rocker cover down to the air intake pipe just in front of the turbo. The catch can - or more correctly "oil-air-separator" - basically replaces this hose.

Simply direct the LH rocker connection to the separator, and run the return from the separator to the turbo air intake. How bloody difficult is that? And the PCV still operates as designed.

BTW, Eddy, there is no Poly Vinyl Chloride involved in the operation of an internal combustion engine. But there is Positive Crankcase Ventilation.

[jet2nv]

i dont have the option to run it back in front of the turbo as im using a 3 inch metal intake and dont really want to run it back into the turbo theres alot of different ways to do the catch can from the DIY i followed on this forum

oh i thought i was goin crazy i knew it was called a pcv valve dont know y i had a mental blank

[toffy]

How will it choke your motor to death? It won't function very well but it won't cause any issue either.

Not literally , my point was , with in- adequate crank case ventilation , everything that seals your oil in your engine will suffer un-necessary stress (your engine gets pressurized , eventually causing oil leaks , not to mention power robbing (if only 1or 2 kw)

[Rolls]

You don't need a very big hole to release the pressure though.

[toffy]

at what rpm? , next time your car is on a dyno , have a closer look

[N1GTR]

at what rpm? , next time your car is on a dyno , have a closer look

[Piggaz]

You don't need a very big hole to release the pressure though.

It ain't gonna breathe out a 2 mm hole though.

[jet2nv]

stock hole is about 5mm and the hose im using is a 15mm hose mmmmmm i think its gonna breathe givin theres 2 of them over the stock 1

[Hanaldo]

stock hole is about 5mm and the hose im using is a 15mm hose mmmmmm i think its gonna breathe givin theres 2 of them over the stock 1

Except you've disconnected it from the intake pipe. The intake pipe is under vacuum, so it literally vacuums the vapors out and assists in breathing. I dare say the stock setup would work better than how you have done it.

[jet2nv]

i just followed all the DIY setups theres a few r33s running alot of power and track cars that have the same setup as mine so i think it should be fine they wouldnt allow a diy on here if it would harm your engine or didnt work

[dori34]

which DIY thread did you follow?

please post the link up.

[Hanaldo]

What track cars are using that crappy can? +1 to link. Happy to be proved wrong, but I just can't see this setup being any better than stock.

[KiwiRS4T]

Some or even many track cars have their catch cans vented to atmosphere (via one or two small air filters usually).

Why? I assume its because at full boost/power they have loads of blowby and they don't want the oil fumes upsetting their afrs.

But I see some Japanese race cars still have their catch cans connected to the intakes. Sometimes they have an oil air seperator and a catch can or two catch cans. I assume the idea is that if you have a proper set up with an oil/air seperator and a properly baffled catch can that allows the oil to precipitate to the bottom of the can then you don't get much or any oil going into the intake but you do get the benefit of the scavenging effect of the intake.

I see a lot of catch cans on TradeMe or Ebay (or on cars for sale) that are really tiny and usually unbaffled and I doubt they do much catching of oil.

For the record non-recirculating catch cans are illegal in NZ except for cars which have low volume certification and are designated as mainly for track use (this is supposed to be supported by the holding of a competetion licence and the keeping of a log book but I don't know how stringently this is enforced).

[jet2nv]

heres the link

http://www.skylinesaustralia.com/forums/topic/309239-oil-catch-can-diy-installation/

ike i said im not really concerned about the quality of the can as i have no blow by nd i dont have a inlet port on the front intake of my turbo hose anymore as im using a metal one and just wanted to plumb something up till i got my custom washer and catch can in 1

[Hanaldo]

All engines have blow-by mate.

The link you posted is different to your setup, he has it plumbed back into the intake. If you've blocked the PCV valve then you won't get the idle problems caused by leaving that hose open to atmosphere, but if you start getting blue smoke at idle or when taking off, you know what it is I was told by a very experienced RB builder to leave the PCV operational, that's enough for me.

[jet2nv]

yeah in the DIY from the thread there where 5 different ways as mine isnt the 100% plumb back like the diy but the rest is i think when i get my washer bottle catch can in one i might just run it back into the front of the turbo i dont really want to remove the pcv its there for a reason

[Bsa]

To the exhaust if your that worried any oil that passes through gets burnt a lot of v8 boys run this method. Pluming into the intake is only good when the can in positioned above the rocket covers that way gravitly keeps oil in the engine but will let vapor into the can then giving clean air to your intake no more oily pipes. It's a very simple thing