Hi Gang,
Start with the EB engine and when it is in boost. The turbos on the EB are small and very efficient, and they begin to spool up as soon as you apply any throttle, and that is where the good low and mid range power comes from. Excellent design by the engineers. So there is really when measured at the intake manifold only vacuum (and low vacuum at that, 6-9") at idle and even low throttle (not enough to cruise and maintain speed) there is only 1-3" we can measure. As soon as we even lightly accelerate there is .5-1# of boost, and the check valve in the valve cover has closes as soon as it see's even a fraction of a # of pressure or 0 vac. So 80% of the operating time is conservative. It is probably closer to 90% of the time, but lets say 80%. There should never be more than a few seconds of non evacuation taking place anytime. That is why even with the RX PCV mod, you will have that brief transition from non-boost to boost when some pressure does build in the crankcase thus the cleanside spearator has to allow flow both ways. But were talking seconds VS most of the time as stock.
Now, the engineers know very well the how and why of all of this, but just as most of you that work for a big company, rarely can you go above your immediate supervisors head and argue something be done differently....it is not good for job security. The auto makers are the worst. So what happened is the PCV system is closed, and meets EPS guidelines even though it is designed the same as a naturally aspirated engine such as the 5.0 or 6.2, and the top mount supercharger cobra and GT500's that all work great. So somewhere a mid management decision maker along with the bean counters decided (NOT the very talented and skilled engineers, they know better) "we dont need to reinvent the wheel here. it passes EPA regs and works on the other engines, so this is how were doing it". and of course any engineers that argued, really did not have a good day. Just the politics of how this works from the industry side. So, once the engines and vehicles are in production, just like GM and the inexpensive ignition switch issue, change does not happen easy, and I can bet right now there will be no real change as all the work is now on the 2.7 eb that will replace the 3.5. Just as happened with the 6.0 diesel. All Ford had to do was replace the head bolts with ARP studs and the engine was fine, yet I wasted $52,000 on a new F350 crew cab loaded with every option possible and Ford voided my warranty because I had a K&N filter on it. (Lincoln dealer honored it and replaced engine twice until I finally did the head studs to correct the issue at the source). So what did Ford do? for 100k miles replace entire engines instead of a inexpensive proven solution. And then dropped the engine. And they are not alone, this is STANDARD in the entire industry. It cost millions and millions to make a .02 cent change. They will never admit to an issue (unless sued by the NTSB), and then dance around all sorts of spin.
I can tell you dozens and dozens of examples over the years since the Pinto and the Pontiac sport wheels paint flaking off in the 70's up through today on all makes/models.
So, the EB PCV system is the same as a 5.0 NA engine, and that cannot work period as any turbo system pressurizes the IM and the IM vacuum is what is relied on with this design.
