,
In a conventional self-draining catch can, this vapor condenses into liquid water and is returned into the engine's crankcase often in the form of an oil-water emulsion that looks like baby diarrhea. The problem is way worse in cold weather. Needless to say that this crap is not good for your engine's bearings as a lubricant and can also contribute to internal corrosion. Valve springs, cylinder walls, and camshafts can be quickly ruined by this sort of contamination.
The Radium Engineering catch can works to eliminate this by trapping the initial water heavy vapor and letting it condense at the bottom of the can where it is trapped before it can flow back into the engine. Here it is heated by the engine coolant in the heater at the bottom of the tank that drives off the moisture. This works great especially in cold weather where condensation is heavy.
Once the oil is above the level of the heating element, it can drain through a filter screen back into the crankcase. There is a dipstick in the can in case you want to monitor the oil level. If the oil level starts to rise, that is an indicator that the lower filter screen is clogged and needs to be cleaned.
Once the vapor is in the can it goes through a separator plate then a large volume steel mesh filter element before the clean and oilless filtered blowby gas is vented, either through a small breather filter of routed back into the intake tract.
Being able to get the oil completely out of the blowby gasses is important, especially if the can is vented back into the intake tube. Oil in the intake charge can greatly contribute to detonation. It can also condense and pool in the intercooler only to get sucked into the engine all at once, potentially hydrolocking a rod.
So far our Radium Engineering catch can is working well. Our oil consumption is down, our engine is happy and our turbo doesn't smoke. We highly recommend this product for modded Subarus that are driven hard, like for track use. It also removes the water from the captured oil on a daily driver as well, the best of both worlds.
We think this catch can is a good addition not just for Subies but for any street driven turbo car.
Sources
Radium Engineering
