| engine isn't going to produce much of an effect on the air metering/fuel delivery. In the case of an engine with a blown piston ring land, there is a much larger amount of blowby. Larger volumes of blowby are going to displace air coming in through the MAS and will result in a leaning effect. But keep in mind, this is a worse-case scenario with an engine that has a critical component failure... By deleting the PCV system you will eliminate the effect the blowby gases have on the metering system, however small or large they actually are. Interestingly enough, I had my Z up on the dyno a few weeks back when this complex we are in had a business expo. I was just doing pumpgas pulls at 18psi and putting down 580RWHP. The open ports on the front of the intake valve covers are the only open ports for the crankcase - in these pulls there was nothing spectacular coming out of these ports either - just a small waft of white smoke that dissipated almost immediately. If I were to guess, in a pull there couldn't have been anything more than a ~16oz volume of gases that came out. Considering the huge volume of air moving through the engine at that power compared to what was emanating from the valve cover ports, the percentage of blowby would have to be a fraction of a percent. On top of that, having the crankcase open ventilated like this offers another benefit of sorts. If there is something mechanically wrong with the engine such as a broken piston ring land, it is going to produce a ton of blowby which you will be able to clearly see coming out of those ports... Interestingly enough, I've found that when my engine is at idle, if I close up the ports on the valve covers with my fingers and hold them for a few seconds, it actually produces a vacuum, not pressure. :)
Enthusiasts soon understand each other. --W. Irving.
Are you an enthusiast? If you are out to describe the truth, leave elegance to the
tailor.
Albert Einstein
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