M20 Air/Oil separator

Condensation and the sludge buildup that
would result was my main concern since the M20
is not dis-assembleable for cleaning like the
Walker/Air Wolf unit. At each annual I soak it in
AvGas and then blow it out with compressed air.

I can understand condensation, but sludge?

With regular flying, and scheduled oil and filter changes, what is the
source of sludge in an M20? Combustion bi-products?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" wrote in message news:OaATc.292632$JR4.125853@attbi_s54...

I can understand condensation, but sludge?

With regular flying, and scheduled oil and filter changes, what is the
source of sludge in an M20? Combustion bi-products?

Well they say that cars driven a short distance suffer from sludge
buildup
when the acidic moisture, created as a combustion by-product, remains
in the oil. I believe the same is true in an aircraft engine. Any
place
where entrapped moisture routinely remains in contact with oil will
form
sludge. Look at the vent tube on an airplane with considerable time
on
the engine. Some have sludge build up because they cool the crankcase
vented gases low enough for the moisture to condense out and remain
on the inside walls along with a film of expelled engine oil.
Depending on
where an air/oil seperator is located it too can run cold enough to
become a collector of moisture and therefore suffer from sludge
buildup over time.

My M-20 is located high enough and out of the engine cooling airstream
to
get and stay relatively hot. Since I can't visually inspect my M-20 I
take the proactive measure of cleaning it out each year.
In fact if my memory serves me correctly I believe the instructions
for
continued airworthiness on the M-20 STC says to clean it periodically.

GaryP

So let me try a theory here.

The lack of positive crankcase ventilation for these
engines is really a bad feature.

A friend measured the PH of the condensate water on the oil dipstick
of an IO-520. PH was 2: Like nitric acid. Having that in
your crankcase is bad.

So why shouldn't we provide PCV by dumping the output of
the wet vacuum pump directly into the crankcase? On the
IO engines, I'd run it into the timing plug in the front.

Then I'd have the air-oil separator on the crankcase breather.

That would give several CFM of air douching the crankcase.

Now the problem is: How much moisture would be condensed out
of the breather air? A gallon/hour? An ounce/hour?

I've wondered if the Airwolf/Walker separator could be modified
so that the oil drain had about a 3/4" standpipe in it with a second
drain added for water that was flush with the bottom of the device.
Then the water could be drained during preflight. The oil would
decant back into the crankcase.

I know there are EPA considerations on this.

Just a thought. I think less corrosion would lengthen the
cylinder life. Bill Hale

I just checked the airwolf.com site. Let me say that I know nothing
about separators. Airwolf's website made me curious. Airwolf shows a
cutaway of the m20 to prove that it's an inferior product but not a
cutaway of their own product. They also claim that the oil from
competitor's products does not flow back to the engine until after the
engine is shutdown. Does this mean that the separator in Jay's plane is
holding four quarts of oil? Maybe the beauty of the M20 is it's
simplicity.
Dave
68 7ECA

Jay Honeck wrote:
Atlas just got his oil/air separator installed today. (For those who may
not know, Atlas is our '74 Cherokee Pathfinder, so-named because he can lift
literally anything we can fit inside!)

We picked this new accessory up at OSH '04, after much debate. (It's a
helluva lot of money for what looks like a welded tin can.) The clincher
(besides the nice clean belly) is that I'll be able to run a full 12 quarts
of oil in our Lycoming O-540, rather than the 8.5 quarts we could hold
before. (Atlas would puke out the four extra quarts, if added.)

It seems logical to assume that more oil in the engine equals cleaner oil to
all engine parts, at all times. This seems like a very good thing, indeed.

Anyone else got one of these things? Are there any "gotchas" to watch out
for, or are they as bullet-proof as they seem?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination

All,

I just checked the airwolf.com site. [...]

I did, too. It's slightly OT, but has anyone tried their remote oil-filter?
The idea looks promising (and our hangar floor would benefit from
"hassel-free" oil-filter change ;-)

Regards

Kai

I did, too. It's slightly OT, but has anyone tried their remote
oil-filter?

Not theirs, but many years ago I raced a VW kit car and the remote oil
filter I added allowed more oil to be in the system and ceratinly allowed me
to get high power for longer before the oil temperature would climb.

Maybe having it in a remote location with some air flow allowed a better
cooling, and maybe the increased oil capacity helped by allowing for a
slower overall climb in temperature. It certainly helped to maintain a more
stable temperature with the short periods of full power that I subjected it
to in motorkana events.

An aircraft is normally only subjected to full power for take off and go
round, and many manufacturers quote full power rating for one minute or
similar times.

Hope this helps,
Peter

Bushy wrote:
I did, too. It's slightly OT, but has anyone tried their remote

oil-filter?

If the installation involves running hoses to the remote location, I'd see that
as an unnecesary extra leak risk.

If the installation involves running hoses to the remote location, I'd see
that
as an unnecesary extra leak risk.

I agree, but in our case the convenience out-weighed the risk.

The previous owner admitted that he only changed his oil every 50 or more
hours, simply because of the incredible mess and hassle. We change ours
every 25 or so, for the good of the engine and because it's really easy.

BTW: The hoses Air Wolf supplied are extremely high quality stainless-steel
braided lines. They appear pretty bullet-proof.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Dave,

If the installation involves running hoses to the remote location, I'd see
that
as an unnecesary extra leak risk.

I'm concerned about this, too. In addition I wonder if there is a noticeable
drop in oil pressure due to the extra resistance in the hoses.

Otherwise changing the oil filter in our Club's Warrior and Dakota IS a mess
and I never stay unstained ... ;-)

Regards

Kai

The plane I just bought has an Airwolf adapter according to the paperwork
but I haven't even seen it yet. I'll let you know.

Mike
MU-2
Helio Courier


"Kai Glaesner" wrote in message
...
All,

I just checked the airwolf.com site. [...]

I did, too. It's slightly OT, but has anyone tried their remote
oil-filter?
The idea looks promising (and our hangar floor would benefit from
"hassel-free" oil-filter change ;-)

Regards

Kai