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Old 07-21-2021, 01:02 AM   #5
Irace86.2.0
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Quote:
Originally Posted by Capt Spaulding View Post
I'm sure this isn't news, but the PCV is a pollution control device. It runs blowby gases and oil vapor through the combustion cycle.

I vaguely recall my drag racing friends from the 60s and 70s going to considerable lengths to scavenge the crankcase. They did it primarily to reduce windage and pumping losses from the crankshaft and rods whipping around and the pistons thrashing up and down. One of the solutions I thought was pretty cool was they would tap into one of the header collectors at an oblique angle and use the negative pressure generated by the exhaust gases flying past to evacuate the crankcase. Simple, virtually free, and very effective.

I'm pretty sure today's generation still uses the same tech.
I know that part. The controversy is more about the debate between open and closed loop systems as it relates to performance and reliability.

He mentioned the same thing. I think there is a difference between a drag car and a street car. The power difference might be more significant on a high horsepower vehicle, especially a V8, and especially on a vehicle trying to maximize power. Also, the drag car sees very little vacuum by comparison.

The alternative to an open system is a closed system with a PCV valve, which will have moments where it isn’t allowing the crank to vent, so I guess the question is which is best/worst: a system with vacuum pulling air and pressure spikes during boost, or a vented system with no vacuum, but no spikes either? I don’t know.
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