[elmariachi]

I have decided (Barry may fart all over this theory because he's a wizard and I ain't) that there are two separate elements here: positive crankcase ventilation and neutral crankcase ventilation. To me positive ventilation would involve a positive suction from the intake system to evacuate all pressure within the crankcase. A neutral setup is more like the accumulator system you describe and is essentially what I have with the rear intake port hooked to the firewall mounted puke tank. Just my opinion I don't think these two yield the same result. Some engines are going to need more than just atmospheric venting to effectively evacuate the crankcase pressure.