catch tank problem

[Guest daz 6576]

ive just fitted a catch tank and took the car for a spin, after a while i stopped and checked it and there was no oil in it at all and the oil is still coming out the dump valve

 

any suggestions please

[Chris Wilson]

If you have a none stock valve that vents to atmosphere so it makes funny noises it will vent oil mist out, a catch tank won't make any difference. Farting noises have their price.

[paul mac]

Farting noises have their price.

 

PMSL, awesome Chris

[Ian C]

I can't say I'm surprised Catch cans are a shiny thing and I've never heard yet of someone going "phew, I'm glad I had mine, it made things better in this quantifiable way". What I have heard is "Hum, I fitted one and 6 months later it's bone dry in there" several times though.

 

You get oil in the air intake system because of the PCV system, it's perfectly normal. If you vent it via a bov, it'll come out the bov. But as it's only a fine mist it'll mostly slightly coat your pipes and never make it to the can.

 

If you get enough oil sloshing around the intake system to need the huge cans I've seen, you've got bigger problems and are simply treating the symptoms. Like earthing kits, I'd say catch cans are a waste of money and for bling purposes only, and only deliver a perceived benefit if you've got an underlying issue you are now masking.

 

-Ian

[Chris Wilson]

They are useful, even necessary, if you ditch the PCV system like I often do though

[Ian C]

They are useful, even necessary, if you ditch the PCV system like I often do though

 

I was speaking about normal cars Not your de-BOV'd de-ABS'd de-airconned de-PCVd track monstrosities

 

(although I draw the line at charcoal canisters)

[Ryan.G]

Catch cans can become useful in certain cars. The oil mist which is vented back into the Intake actually lowers the octane level of the mixture and in some case i have found that it has enabled me to get a couple more degrees of IGN in by fitting one and still be Safe.

 

Have only seen one supra with out it plumbed in and that's Wes's car.

 

Ryan

[Kranz]

I can't say I'm surprised Catch cans are a shiny thing and I've never heard yet of someone going "phew, I'm glad I had mine, it made things better in this quantifiable way". What I have heard is "Hum, I fitted one and 6 months later it's bone dry in there" several times though.

 

You get oil in the air intake system because of the PCV system, it's perfectly normal. If you vent it via a bov, it'll come out the bov. But as it's only a fine mist it'll mostly slightly coat your pipes and never make it to the can.

 

If you get enough oil sloshing around the intake system to need the huge cans I've seen, you've got bigger problems and are simply treating the symptoms. Like earthing kits, I'd say catch cans are a waste of money and for bling purposes only, and only deliver a perceived benefit if you've got an underlying issue you are now masking.

 

-Ian

 

 

Probably true for most run of the mill engines.

 

During base engine development on testbeds we normally fitted a catch can to measure the volume of blowby oil. This was additional to carrying out blowby gas volume & carry over tests (the latter diverting the blow by through a series of paper filters that caught the oil & were weighed before & after to give extremely accurate grams of oil per hour).

The catch cans were only there as a safety system in case these prototype engines chucked out far more than the breather system designers had calculated.

Once the breather systems were fully developed then the catch cans were eliminated and the engines ran on production spec components.

 

So, if you are running a stock engine in good condition then they are probably a waste of time. If you are carrying over that much oil you probably have a problem with ring seal.

However, on a monster of an engine with modified breather system it is probably a good safety system.

 

Sadly, the only way you can tell if you need one is to fit one & see how much it catches!