Catch Can question

[Gilly]

Just a catch can query for those who run them.

Basically I want/need the atmospheric breather but I'm trying to avoid the massive amount of fumes they put out. the idea I had was to have a low restrictive piece of foam or some other "breathable" item in the can itself, theory being the oil mist clings to the foam and runs down in to the tank to be drained.

a lot of the cheap cans are just cans and allow a lot of the oil mist just to vent instead of being "caught" as the name catch can suggests it should!!

the can I'm using is a 1 litre item with a top mounted breather, it will not be venting back to the intake at all, it will be as simple as both rocker cover fittings linked to the can (CA18DET). I understand the breather is to lower pressure in the tank and also adding extra "restriction" via the foam is not overly beneficial but if I could minimise the density of the foam is there merit in my thinking??

open to all opinions peoples

thanks

[rthy]

an old trick I read ages back (maybe autospeed) is to use those stainless kitchen scourers, apparently they work well and very cheap

[AsleepAtTheWheel]

Gillster,

Correct me if I've got the wrong idea here but if you're not going to plumb the catch can back into the intake, aren't you going to be forcing all of the pressure released from your rocker covers out of the top breather filter thus causing it to get soaked in oil and release that muscle car oil smell anyway? (This is assuming that you've got the usual set up of an inlet and and outlet port plus a bottom drain valve).

You could get some super-low density foam, as you said, like the stuff they use in fish tanks for biofilters (kinda like that plasticky-rubber fake grass stuff that they put on thongs etc.) which might work but temps might be a prob...

[Gilly]

yeah thats the shit I want Ando, I just couldn't think of an example of where I'd seen it :lol:

I don't think the pressure is that extreme, I've seen this setup done a bit and it appears to work fine, with minimal mess. I just want to make it more effective :P and I'm a sook and get headaches from external oil vents :P

I don't want any oil mist going into the intake pipe or intake ala stock. in the stock setup the inlet cam is vented to the manifold via a one way valve (PCV) which really means it's only relieving pressure off throttle (vacuum opens the PCV) The intake cover is vented to the intake pipe meaning I get a nice collection of oil in my cooler and piping and a gunky throttle body :( The stock venting setup means the engine breaths oil which inturn lowers the detonoation threshold which is no good for turbs engines. I mean you prolly know this I'm just saying why I'm exploring this avenue

[ke70dave]

ahh thats an interesting point gilly, I'm not Exactly sure what your trying to achieve, but from what I understand you are trying to catch the oil inside can rather than letting it get blown around, and getting an oily smell out the vent?

if this is so, one idea I just had, which woudl be a little hard to make (require pretty much a custom catch can, but it was to create a complcated "matrix" of baffles inside the catch can.

I thought of this idea as I was thinking back to my dads boat. he had a thing he coudl put on the front hatch, and it let in fresh air but woudl keep out the water. (either raining or heavy seas)

here's a pic of what I'm thinking, side on view (so would be a square catch can I guess)

your could even make those "panels" of metal out of a "V" shaped peice of metal, and then where the metal joins the side of the catch can, cut a little hole, so the trapped oil drains down the "V" and out the little hole, and then goes out the drain pipe.

question, does the drain pipe go into a tapped hole in the sump?

http://www.ae86drivingclub.com.au/dcimages/4/8/4/3/151686.jpg

[Leandro]

Made my own ctach take out of a stainless steel soap dispenser of all thing lol ( I work at bunnings ), any way I put some steel wool in mine. I jammed a lot of fine grade steel wool in there and I've never looked back oil stays in can and not everywhere else and my intake in still clean ... might be an idea if you want pics of ill try and get some


Leandro

[Gilly]

pics would be sweet Leandro, I'm pretty sure I know where you are coming from but pics would be good as a reference.

Dave, that was something I considered but I already have this can here and it owes me a bit :lol: I think the foam idea is a goer, surface area wise it's a winner.

you only really find this shit out by giving it a go I guess.

[kaibeecee]

as long as the can is internally baffled, the oil will stay in the can. I researched catch cans and their workings for months and came to the conclusion that the best setup is baffled internals, flyscreen mesh over upper inlet of can, sponge/steel wool in bottom 3rd of can

obviously a helpful thing (and a lot of people overlook it), is gravity. gravity feed your lines downwards, this relieves lots of backflow, and clogged lines

I've seen super cheap cans filled with coke can offcuts working wonders.

as for venting, if it's venting to atmosphere, theres nothing you can do about controlling it, only restricting it's output, or using a small sock of sorts over the outlet.

[Gilly]

cheers dude

a lot of good info there ;)

I'll have a crack tomorrow and post my results.

[AsleepAtTheWheel]

Some good info from these articles on Autospeed

The one that Sam_Q was talking about:
http://autospeed.drive.com.au/cms/article.html?&A=0338

A newer version:
http://autospeed.drive.com.au/cms/A_1101/article.html

If you CBF reading them through, the filter medium that they use is 1) Steel wool scourers and 2) household dishwasher sponge.

Either way, you'll look good to your other half cause they'll think you've finally decided to help out with the housework :lol:

[slidin 86]

Steel wool in a stocking or 2, so that the oil stays in and the stocking stops the oil and metal scards of the wool getting sucked back in if it's plumb back.

[r3zzz4]

Don't know if it's any help Gilly, but in refrigeration we use "oil seperators".

Basically a vertical cylinder, inlet and outlet at the top and a conical piece of wire mesh over both the in/outlets.

The mesh is very fine and because of the shape, catches up to around 98% of the oil blowing through it.

These round at around 1500- 2500 Kpa just to give you an idea, with lots of oil passing through them.
Simple but effective.

Google it if you want a clearer idea.

Dane.

[unit101]

In regards to where the oil go's- you can plumb it back into the sump, but if you are going to have foam or mesh inside the can, I'd be inclined to just put a tap on the bottom of the can so you can just drain the excess when needed- I wouldn't want to risk pieces of foam etc making their way into my oil supply.

[r3zzz4]

Yeah, put the tap on the bottom so you can drain it
Id say he just wants a more efficient way of taking the oil out of the emissions from breather.

[Gilly]

I bought a plastic JAZZ tank

I have a good idea of an effective oil air seperator that will work in an EPA friendly plumback manner whilst seperating the oil from the air. it might not be a unique idea but it's a good solution.

I'll suss that refridgeration stuff out Dane, cheers for the info.