Venting of Lycoming 0-290 D Engine
On Apr 29, 5:53 pm, "Morgans" wrote:
"Orval Fairbairn" wrote
The PCV valve was government mandated for pollution control only! It
makes no difference to the gov't if it harms your engine components, as
long as it meets THEIR requirements. It would be stupid to install one
on an aircraft.
While I believe your stand has merit, I think the truth is somewhere in the
middle. While some harm may be done, it is very little.
Otherwise, I don't think I would have gotten two of my last Detroit engines and
induction systems to over 200,000 miles. Added to that, the fact that these
engines had _no_ problem with their induction systems, at those miles.
--
Jim in NC
Acids are formed in the crankcase, but mostly as a result of
condensation mixing with the oil and allowed to sit for some time.
Water breaks down and combines with elements in the oil to form those
acids, with the dissimilar metals acting as catalysts. The acids eat
bearings and cams and cylinders and pistons and such stuff.
The PCV system is better than a straight vent, where it can be
made to work. The intake manifold draws the blowby gases out of the
crankcase, those gases including water vapor, unburned hydrocarbons
and combustion byproducts. The volume of gases drawn out is larger
than the blowby gases, so filtered air is let into the case at some
other point. This purging keeps the case cleaner than with just an
overboard vent.
The PCV gases are reburned and blown out with the exhaust. They
do much less damage that way, both to the engine and the environment.
Dan
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