Oil Temperatures

The oil does stay clean between oil changes. I change around 40 hours. I
have about 200 hours on this factory overhauled O-360 engine. I have to
run 100LL in it. I add a quart about every 13 hours. I am going to play
with a winterization plate this winter. I believe the Piper Arrow that
has the same engine configuration has a winterization plate that has
about a inch and a quarter diameter hole in the middle. That seems too
small though.

Ross

" wrote:

Ross

I have a 172M with an O320E2D @1700 hrs TTSN with the same oil filter
system that likewise is cold blooded. My guess is that ours has very
little blowby as the oil also stays clean for many hours after a
change. It has been run mostly on MoGas, so the contamination load on
the oil is low. Does your oil stay clean unusually long too?

Have you tried covering part or all of the oil cooler?

Ours does not have a Vernatherm element installed in the oil filter
adapter - only a plug. Does yours?

My guess is you have a very good break-in. I don't think it is
something to worry about.

The justification for having the oil run above 180 degF though, is
that the dew point of the combustion products is about 180 degF.

Newps wrote:
230 is way too high on a regular basis for oil going to the cooler much
less returning to the engine from the cooler. The generally accepted
number is 180 degrees at the point where most of us are getting our
readings from.

My understanding was 180 in the sump with a 50 degree F increase in the
engine (hence the 230). Maybe I understand it wrong. Doesn't the engine
manual give the specifics?

Let me guess - your oil gets gray due to lead sludge, rather than
coffee colored like my 172. You probably have a very tight solid air
baffle system with little gap developing under air pressure loads, the
engine cooling fins are clean, and the alignment of the casting molds
for the heads happened to be very good at the Lycoming factory. All
good things that make for good cooling, and a good piston ring
break-in.

Your oil consumption is higher than mine but acceptable of course. I
get about 30 hours to a quart, and see no increase in consumption
despite the high time. I cruise at lower power settings and try to
keep the cooling system in perfect order.

We bought the airplane when it was new so I'm the only pilot. My
primary concern now is when to major it as a matter of principle. I
doubt I could get back to the present smoothness and oil consumption
even after a major, so barring any changes, I'm still inclined to
leave it alone. Lycoming says to major every 12 years, which would
have put me halfway thru a second major. But really, taken care of,
they seem to run almost forever.

I covered the oil cooler air inlet last winter to get some semblance
of warmth. When the cover was left (forgotten) last spring, it got
warm (but just upper green) fast. Otherwise it usually only can get
to the bottom of the "L" of "oil temp" on the Cessna gage.

I also feel Cessna has a superior baffling system for their Lycomings,
compared to Piper, and especially to Grumman.