Reply to thread

Message: <blockquote data-quote="MachSVT" data-source="post: 1561628" data-attributes="member: 31918">Wanted to add...Turbo applications are extremely difficult for proper crankcase evacuation. In the past, I've tried several methods to create a negative pressure.The most ideal setup for negative pressure is to utilize the inducer side of the turbo as a vacuum source, but due to turbochargers are very sensitive to contaminants being introduced into the inducer wheel (throwing them off balance which will wipe out the turbo bearings / seals) that setup is a gamble. You could utilize a oil separator, provided it is 100% effective and you stay on top of periodically checking it to be certain it doesn't overfill. This method will supply vacuum to the crankcase regardless of RPM.The other option is post turbo, is much more safe, but requires use of a PCV (which introduces restriction of vacuum and I've never found a PCV that did not leak boost into the crankcase) and is only good for evacuation when not in boost...which is somewhat pointless IMO.I ended up (again, in the past) having ridiculously huge free vent filters either off my valve cover, or VERY large lines running to a free vented catch can. While this worked, venting from the valve covers is less than ideal, because we are expecting the pressure to vent out the top of the engine, which counteracts the oil trying to return from the turbo / heads.All of that said, if free venting to atmosphere, the best setup is to vent from the engine block, which depending on application can be very difficult. If an older car that is converted to crank trigger ignition, we would utilize the distributor hole and T that into a hose off the valve cover and then into a free vented catch can. While we still could not take advantage of creating negative pressure, this showed the best results.This topic is one great example of why I prefer positive displacement blowers, as rotor packs are much more durable than turbo inducers, therefore, I can run a completely sealed crankcase evacuation setup that is void of a PCV valve.Anyway, hope this helps.</blockquote>