Quote:
Originally Posted by Vreimann
...So I guess one could say that we have a PCV catch can if you frequently empty out the intercooler of the oil.
Not sure about the purpose of the heater except it may be there because of us Canucks living in the cold, but I doubt it is there to vaporize the oil mist.
Question is that with the available vacuum how difficult will it be to get a catch can that will work without screwing up the original design pressure drop. That section of plastic tubing looks to be quite short.
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Unfortunately the oil mist doesn't all stay in the intercooler. There's enough of it that gets all the way up into the intake on the other side of the intercooler. At least on my car and on the pictures posted by others. I haven't seen any pics of the intake that doesn't have the oil film.
I believe you are correct on the heater. The TDI guys have reported issues with catch cans (and their stock intercoolers) freezing up due moisture content in the blow by gases. Think this is part of the reason the 335d stock crankcase vent pipe is ran along the top of the engine like it is ... to keep it warm.
The flow rating on the "catch can" and its piping should be choosen such that it will be low enough to allow the proper amount of blow by to pass without causing excess restriction. Otherwise excess pressure buildup in the crankcase can occur which is not a good thing. That's why I'd be a little concerned with just using the 335i setups as I haven't seen flow data on them.
Regarding trying to vent it to the atmosphere ... if the engine is designed for that then that would be fine. My 2004 Cummins Ram and the Cummins B3.3T I repowered my old Jeep Wrangler with do this. But if the crankcase venting was designed such that it relies on vacuum from the intake to help pull crankcase gases out ... I'd be cautious of damaging the internals of the engine without seeing hard data on the effectiveness of this approach. It might work great, but I haven't seen any evidence of that yet.
Also, the 1/4 mile track I've been to specifically require you not to have the crankcase vented to atmosphere due to safety issues with the blow by oil getting on the track surface.