Just curious what members are seeing as far as catch can smoke since I have no locals with a vented can that I know of.

My can is mounted right on the firewall, and is a DIY can but it is baffled, and stuffed with copper SOS type pads, and vents through lots of 1/8" holes drilled into the cover, after the vapour passes through my baffling and filtration.

I notice my smoke can be VERY visible at times, about as much as 2-3 lit idling cigarettes would cause. It doesnt really bother me, as I know my engine isnt on fire, but Im sure people at stop lights think that may be happening.

Im curious if it is so visible because I dont run a filter on the top, or if because my hood is raised 3/8" at the rear, and I have the firewall rubber seal removed, giving the smoke an easy exit at the back of the hood.

Trying to think of the easiest way to minimize the visibility, I just recently moved it to the firewall, it used to be behind the headlight and I could not notice it at all.

Does your setup smoke noticeably ?

 

I also have a homebuilt catchcan with baffles and a filter on top. 2 -12AN lines run off the valvecover only, also using the factory valvecover baffle.

Stock motor so clearances are still pretty tight, doesn't really collect any oil and don't see any smoke at idle, but on the dyno there was plenty of smoke coming out during a pull.

 

I have a catch can setup here (see pic) ... it does let off some vapor that is barely noticable at operating temp. I kept the baffle and did 2 fittings on valve cover only.. I dont get any oil in the catch can itself at the moment....

 

Most of what you're seeing is simply water vapor. as the oil heats up it boils off moisture and other things in the oil.

 

I can see vapor coming out of my can especially befire the motor us up to temp. Ots probably uyst condensation. If u empty the can and mostly water comes out then its condensation. If u get a wendys chocolate frosty to come out there is a bit of oil mixing in

 

Ya its generally just slightly yellow water that drains out of the can.

Do you guys think stuffing it with a different filtration would make a difference? Right now I have it fairly tight with SOS copper pads, pretty cheap to do that since I get them at the dollar store. But I could switch to something more dense, like that stuff they sell at pet stores for fish tank filters, or even scotchbrite pads are pretty dense, i could cut them into the square size of my can and make a big sandwich of them.

None the less I think i need to try something else, Id like to minimize the smoke atleast, last thing I need is to tip off a smart cop at a stoplight that my emissions equipment is modified

 

This. Seems more pronounced if you are on e85/ e98 as well.

I get a little steam and condensation burning off until it comes up to temp idling... then it will tapper off and stop.

 

yea if it's humid, below dew point, or just cold then the steam/smoke will be more pronounced..

it shouldn't really have a smell, maybe slightly like oil vapor, and when it leaves the can it should disappear fairly quick. if it doesn't then there's more than just a little water vapor and blowby in it

 

Do you think a different filter type stuffing would make a difference? Or would closing off the back of the hood work better? My rear seal was messed up is why I got rid of it, I could get one at the junkyard probably there is a nice EF hatch there.

Or scotchbrite pads as the filter... but I like the copper sos pads Im running, you get 8 for a dollar and looks pretty cool if you look in the holes and see copper, I have a thing for copper

Id like to minimize it visually though

 

As long as nothing is steel you're ok. copper works well because it doesn't corrode.

a can with physical baffles would better but what you have is fine.

 

It does have 2 baffle plates inside, the "end" of the path for the vapours though is just stuffed with the copper. Maybe I could pack some more in there and just fight the cap on lol

 

how dense do you have the can packed?

 

There is a fine line between too much packing and not enough.

not enough packing and the oil and blowby vapors aren't adequately removed from the air inside the catch can and you risk blowing it out of the can and/or saturating the filter(s) with oil, reducing their effectiveness.

too much and there's a huge restriction in venting crankcase pressure properly. you could actually increase crankcase pressure with too much packing inside the can.

 

Its fairly dense, SOS type pads are pretty dense from the factory and I probably compressed them a bit in the can but Im sure theres breathing room.

I think Im going to simply replace the seal on the back of the firewall and see if cutting off that exit point will help, even though I slightly fear it will then just billow out the fender seam of the hood

 

I would imagine it's only visible when cold, when the motor is first warming up, or at a dead stop or low speeds correct? if you can still see it at moderate speeds there's an issue.

replacing the seal might help but with the hood spaced not much.

if you can make it take longer for it to exit the engine bay then the vapors should have enough time to cool down and condense, eliminating most if not all of the visible smoke

 

Ya Ive only ever noticed it at idle, once moving its gone. I scared my sister just yesterday, pretending something was probably under the hood burning but I pretended not to care and said the wind would put it out lol

It really doesnt bother me like I said as I know its normal, but passengers and johnny law id prefer not see it

 

My catch can vapor was invisible before I cracked my ringlands. Seeing smoke from my catch can breather is how I knew my block was going.

 

To a point that's true. if you live in a hot humid place then the engine oil tends to absorb more moisture which means as the engine oil warms up there will be more noticeable water vapor leaving the can.

 

Water vapor and smoke are two entirely different things.