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Old April 24th 06, 04:09 PM posted to rec.aviation.homebuilt
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Default Water in our oil, or just alot of hot air?

And like I said,
my oil analysis results show no water at all, zero. As for the engine
making water, of course it does, and it goes right out the exhaust as
you said.


Most of it goes out the exhaust. Some of it squeezes past the rings,
since everything is still cool and the gaps are larger, and it
condenses in the crankcase. It does it to a lesser degree once it's
warmed up.

I don't think the engine stays very cold for any length of
time once running. Those babies get hot, and quick, even in the winter.


Only if your idea of winter is around 40 F. Many of us live in
climates that get much colder than that. We have airplanes here that
never see over 150 F on the oil temp in winter, and seldom more than
300 on the CHT.

I doubt if they collect much if any water during start up.


I've taken the rocker covers off a brand-new engine after it's been ground run for five minutes, and they're full of water. If I take them off after it has 200 hours on it, they're rusty.


I also don't
think the oil turns to an acid capable of dissolving the engine.


You just haven't seen it, so you don't believe it.

I could be wrong, as I haven't done the research, but then, I don't think
anyone else has either.


More "show me." Lycoming and Continental and the people who make engine
oils HAVE done the research and published it. Many more, who aren't
trying to sell oil or additives or engines, have done it as well.

Some say they have, but they aren't showing it
for us to see, at least not that I'm aware of. I realize that the 180
deg is probably meant as a guide, but they do state specifically that
if you don't hit 180, the water won't evaporate.


Water's vapor pressure rises with temperature, if you remember your
physics. Raising the vapor pressure drives it of sooner. It doesn't
have to boil. 180 is a recommendation. Below that, the water might form
in the case faster than it will evaporate, and you'll have increasing
amounts accumulating in the engine.

The research is there. Here are some who have experience in the
area:
http://www.sacskyranch.com/corrosion.htm

http://doc.tms.org/ezMerchant/prodtms.nsf/ProductLookupItemID/JOM-0505-54/$FILE/JOM-0505-54F.pdf?OpenElement

http://www.ramaircraft.com/Maintenan...mendations.htm

http://www.memagazine.org/backissues...italsigns.html

Lots more if you Google it.

Dan