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FluidMotorUnion
06-23-2011, 01:18 PM
That’s one more item we can check off the 318’s fabrication list.

Fabrication just finished making a quick and easy catch can for the 318i turbo build. For those not in the know, an oil catch can aids the PCV (positive crankcase ventilation) system. Normally, oil vapor and blow-by gases (gas that blows through the combustion chamber, past the piston rings and into the crankcase) are routed through the PCV system, out of the crankcase and back into the combustion chamber, where they are used in combustion and removed as exhaust. Over time, the oil vapors can thicken along the walls of the PCV system, creating a gunk that will necessitate a thorough cleaning of the system. This is where the catch can comes in. The catch can is placed inbetween the crankcase and the intake in the PCV system. It’s built such that the oil vapor will travel through some steel wool (or other material) inside the catch can, and that gunk will be caught by the catch can, collecting there until the driver empties the catch can of all the nasty buildup inside. The resulting vapors can then either be sent to the intake system, or vented into the atmosphere. Draining a catch can is an easy technique (so long as the catch can is easily removable), and is usually done at the same time as an oil change. We made the design on this one pretty simple, as there is already a LOT going on in the 318’s engine bay.

http://www.fluidmotorunion.com/wp-content/uploads/2011/06/flak1.jpg
http://www.fluidmotorunion.com/wp-content/uploads/2011/06/flak2.jpg
http://www.fluidmotorunion.com/wp-content/uploads/2011/06/flak3.jpg

The filter we’re using to vent the vapors to the atmosphere is pretty interesting. It’s about half the size of a thimble, and screws into anything you can put a normal bolt into. The construction of the filter itself looks as if its made of a million tiny solid beads, but it manages to push out a good amount of air. Quite the interesting little doozy, we must say.

http://www.fluidmotorunion.com/wp-content/uploads/2011/06/flak4.jpg

Finding a place for it was a little trickier. There’s plenty of space in the passenger side of the engine bay, but there’s already so many components over there that it started to look a little cluttered. Therefore, we found a perfect spot for the catch can itself (right behind the intake manifold) and the mount to hold it in place (coming off the bolt on the dipstick mount). Once we polish the intake manifold to match the catch can and charge piping, it’s going to look pretty slick.

http://www.fluidmotorunion.com/wp-content/uploads/2011/06/flak5.jpg

motocaddy
06-23-2011, 02:30 PM
sweet can! have you guys considerd a crankcase evacuation system. you would essentially take that hose from the valve cover and run it into the exhaust, post-cat and o2. they make little nipples that stick into the exhaust flow and create vacuum through venturi.

the reason i bring it up is space and that you're polishing parts in the bay. i have a lot of polished parts on my wife's jetta (mani, valve cover, motor mounts, etc.) and we were getting a lot of oily residue from having a vent-to-air catch can in the bay.

so far, we're really happy with our evac system. only downside is that sometimes the exhaust smells and/or puts out some white smoke.

1badg35
06-23-2011, 02:49 PM
wow, I need this for my b6 s4 4.2. I am having issues with my crankcase vent valve, just replaced the entire unit a few weeks ago, and already it is getting gunked up and causing it to not function fully. I might be calling you guys soon to fab a similar unit up for me so i can eliminate that common problem with this car.

FluidMotorUnion
06-23-2011, 03:09 PM
wow, I need this for my b6 s4 4.2. I am having issues with my crankcase vent valve, just replaced the entire unit a few weeks ago, and already it is getting gunked up and causing it to not function fully. I might be calling you guys soon to fab a similar unit up for me so i can eliminate that common problem with this car.

For sure. You can either ring the office (815-230-2900) or shoot me an email (andrew@fluidmotorunion.com).