Exxon Elite Oil: More favorable oil analysis or simply coincidence?

How unfavorable was the single analysis, hmmm?
denny
Maule Driver wrote:

Interesting point. I had my case split and cam replaced based on 1
unfavorable analysis.

Denny wrote:
How unfavorable was the single analysis, hmmm?
denny
Maule Driver wrote:

Interesting point. I had my case split and cam replaced based on 1
unfavorable analysis.


What do you think?

I had a string of 14 previous samples on my Lycoming 360 from 35hrs TT
to 1146hrs.

I would get an iron reading of '25.0' for about 35 hours of operation
throughout this period of 7 years.

On the 15 sample I got an iron reading of '101.0' for 36 hours of
operation since last analysis.

A subsequent filter analysis did show some very fine iron filings. The
filings felt like fine silt to the touch. No chunks or sand size particles.

Asked around for input (including here). In the end, it was clear
'something' had begun to happen. Everything else checkable, checked out
ok. I planned to keep flying this aircraft for at least 3 more years.

I had it split. There were indications that 2 lobs on the cam had just
begun to spall.

Pete, I have no criticism of your determination to maximize engine
longevity... I have a pair of engines I'm babying along...
Yes, I have rebuilt aircraft engines sob, sob...
Let me play devils advocate here based on the additional information
you have given to other posters..
1. you run the engine regularily..
2. you preheat in cold temps...
So, let me be the first to say you are wasting your money on
semisynthetic, multiviscosity oils! Yes, wasting your money, kemo
sabe...
You should be using a good, single viscosity oil, changing the oil
religously at 25 hours, and your filter at 50 or 75 hours... Having
that bright, golden, fresh, slippery, oil in the engine will do more to
prevent wear than anything else you can do...
Every branded oil company has an excellent, single viscosity, petroleum
based oil, with Lycoming additive that they can barely give away... An
industry secret that FBO's know... Let me suggest Phillips 100AW at
less than half the price of 15W50, or 20W50 as a good oil to use...

Now, this advice does not apply to engines that routinely go weeks
between starts, that are started stone cold, etc.. There a
semisynthetic, multiviscosity oil is probably the best - actually a new
owner that runs them often is the best, but it's an imperfect world...

The other habit I would forego is ground running... More engines than
you can wave a stick at are burnt' up getting the oil temp "into the
green"... By the time you run up and taxi to the runway that engine
is ready to go..

The last comment I will make on this is that changing oil brand/type is
guaranteed to obscure the analysis for 2 to 4 changes...
No, I don't do oil analysis... I change my own oil, I cut open my own
filters, i clean my own plugs, and I listen to my engines... Not
perfect, but it's an imperffff, uhh, geez the echo in here is
deafening...

denny

Denny wrote:

The other habit I would forego is ground running... More engines than
you can wave a stick at are burnt' up getting the oil temp "into the
green"... By the time you run up and taxi to the runway that engine
is ready to go..

Thanks, Denny. I will seriously consider your advice about the oil type.
The advice above I am not sure I agree with, however. My Bonanza is
equipped with a turbo-normalized IO-520, something I may have failed to
mention earlier.

If the oil is not warm enough, the engine will most definitely overboost
two inches or more of MP.

--
Peter

Peter R. wrote:

If the oil is not warm enough, the engine will most definitely overboost
two inches or more of MP.

Hi Peter, with apologies for the tangent from the original topic: would you mind
briefly educating us (well, me) about how low oil temperature leads to overboost?

Thanks.

Denny,

I completely agree with everything you said.

If however, there's a chance that the owner might occasionally start
the engine around 40Fdays without pre-heating (not exactly a temp that
normally requiring pre-heating), the Phillips X/C 20W50, at only $40 a
case, would be a better choice than Phillips 100AW or 100AD.



Denny wrote:
Pete, I have no criticism of your determination to maximize engine
longevity... I have a pair of engines I'm babying along...
Yes, I have rebuilt aircraft engines sob, sob...
Let me play devils advocate here based on the additional information
you have given to other posters..
1. you run the engine regularily..
2. you preheat in cold temps...
So, let me be the first to say you are wasting your money on
semisynthetic, multiviscosity oils! Yes, wasting your money, kemo
sabe...
You should be using a good, single viscosity oil, changing the oil
religously at 25 hours, and your filter at 50 or 75 hours... Having
that bright, golden, fresh, slippery, oil in the engine will do more to
prevent wear than anything else you can do...
Every branded oil company has an excellent, single viscosity, petroleum
based oil, with Lycoming additive that they can barely give away... An
industry secret that FBO's know... Let me suggest Phillips 100AW at
less than half the price of 15W50, or 20W50 as a good oil to use...

Now, this advice does not apply to engines that routinely go weeks
between starts, that are started stone cold, etc.. There a
semisynthetic, multiviscosity oil is probably the best - actually a new
owner that runs them often is the best, but it's an imperfect world...

The other habit I would forego is ground running... More engines than
you can wave a stick at are burnt' up getting the oil temp "into the
green"... By the time you run up and taxi to the runway that engine
is ready to go..

The last comment I will make on this is that changing oil brand/type is
guaranteed to obscure the analysis for 2 to 4 changes...
No, I don't do oil analysis... I change my own oil, I cut open my own
filters, i clean my own plugs, and I listen to my engines... Not
perfect, but it's an imperffff, uhh, geez the echo in here is
deafening...

denny

Dave Butler wrote:

Hi Peter, with apologies for the tangent from the original topic: would you mind
briefly educating us (well, me) about how low oil temperature leads to overboost?

I am not a mechanic and I have only been flying a turbonormalized aircraft
for three years now, so I may have some of the details wrong, but if so, I
suspect it will be corrected immediately by someone more knowledgeable.

Are you familiar with how a turbocharged system works? Based on my
understanding, a turbocharged system works by rerouting engine exhaust
gases through a turbine that then spins at a high rate of speed, which
compresses the air being sent to the cylinders. This compressed air will
allow for optimal combustion at much higher altitudes.

Here's the Wiki article on turbocharging:

http://en.wikipedia.org/wiki/Turbocharge

In order to prevent excess pressure from building within the system, most
turbo systems have a device called a wastegate that opens and closes based
on pressure within the system. Too much pressure in the system and the
wastegate opens, allowing this excess pressure to be vented outside, rather
than remaining within the system and creating potentially damaging stress
inside the cylinders.

This wastegate is operated by oil and, as you know, colder oil flows
slower. Slow flowing oil inhibits the ability of the wastegate to quickly
open and dump the pressure outside the system. In this overboost
situation, excess pressure will show on the manifold pressure gauge as one
to many inches more manifold pressure than what should be optimal for that
aircraft.

My Bonanza is supposed to show a manifold pressure of 29.92 at full
throttle, but I have discovered that oil even 10 degrees colder than the
recommended temperature can result in a temporary overboost by an inch or
so, or roughly 30.7-30.9 inches MP.

Tornado Alley, the designer and manufacturer of my Bonanza's
turbonormalization kit (which is a bolt-on turbo system to a normally
aspirated piston engine), points out in their documentation that a
momentary overboost at full throttle is normal, unless this overboost is 2
inches or greater than the 29.92 inches. If this happens, they recommend
reducing throttle until the MP drops back to 29.92. In my estimation that
would be extra work at a critical point during takeoff.

I have learned that warm oil and a properly maintained engine are the keys
to preventing an overboost of 2 inches or more.

--
Peter

"Peter R." wrote in message
...
Denny wrote:

The other habit I would forego is ground running... More engines than
you can wave a stick at are burnt' up getting the oil temp "into the
green"... By the time you run up and taxi to the runway that engine
is ready to go..

Thanks, Denny. I will seriously consider your advice about the oil type.
The advice above I am not sure I agree with, however. My Bonanza is
equipped with a turbo-normalized IO-520, something I may have failed to
mention earlier.

If the oil is not warm enough, the engine will most definitely overboost
two inches or more of MP.

A good summation he http://www.avweb.com/news/columns/186619-1.html

Is this what Denny is referring to about "burning up the engine"? With a
TN'ed engine, it's even more critical.


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO (MTJ)

We switched from Aeroshell Multigrade 15w50 to the Exxon Elite 20w50 in
a Cherokee Six with a Lycoming 0-540-E4B5. We had decrease in metals as
well. Decided to just stay with the Exxon. This was by no means a
scientific study. We had 4 analsis before the change and are now up to 4
after. These were 40-50 hour changes in southwest Virginia in various
seasons. The plane if flown roughly every 2 weeks year round.
Peter R. wrote:
With my rebuilt Bonanza engine, I have been faithfully sending in every oil
sample drawn from the 40-50 hour oil change to Aviation Laboratories for an
oil sample.

When I receive the report from the lab, I log it to an MS Excel spreadsheet
in order to catch any trends. Currently I have seven oil analyses logged
over the 300 hours that this engine has on it.

Normally I use Aeroshell Multigrade 15w50, but last winter I used Exxon
Elite 20w50 for one of the oil changes under the assumption that it would
combat corrosion that might occur from condensation build-up in the oil
after engine-shutdown.

An interesting data point has emerged that has me curious. All of the
metals discovered in the oil analysis after using Exxon Elite were of
significantly lower quantities when compared to the analyses from the
Aeroshell multigrade, either before or after the use of the Exxon Elite.

Is this just coincidence or does this indicate that perhaps Exxon Elite
does provide better engine lubrication?

My aircraft is a few hours away from an oil change and, as we approach
winter in the Northeast, I am considering using Exxon Elite again.

Robet Coffey wrote:

We switched from Aeroshell Multigrade 15w50 to the Exxon Elite 20w50 in
a Cherokee Six with a Lycoming 0-540-E4B5. We had decrease in metals as
well. Decided to just stay with the Exxon. This was by no means a
scientific study. We had 4 analsis before the change and are now up to 4
after. These were 40-50 hour changes in southwest Virginia in various
seasons. The plane if flown roughly every 2 weeks year round.

Interesting. Thanks for sharing your observation.

--
Peter