Oil Change Regularity

I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

In the other threads it seems many have a higher frequency than this.
Would people chime in with how often calendar and flight time they
change? For those who have what I'll call "short duration changes"
based on what's above, what are the things you worry about happening
if you go longer. Anyone who goes longer please also give your
philosophy.

Thanks,
z

1979 172N, we change every 50 which works out to twice a year pretty
consistently. We do an analysis at every change. It's been operated this way
for 20 years without any obvious problems and is getting close to TBO.

"zatatime" wrote in message
...
I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

In the other threads it seems many have a higher frequency than this.
Would people chime in with how often calendar and flight time they
change? For those who have what I'll call "short duration changes"
based on what's above, what are the things you worry about happening
if you go longer. Anyone who goes longer please also give your
philosophy.

Thanks,
z

I change mine every 25 hours. I wouldn't like to only fly it 50 hrs a year
for one thing, but I would want old oil to sit in the engine for a year.

zatatime wrote:
I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

In the other threads it seems many have a higher frequency than this.
Would people chime in with how often calendar and flight time they
change? For those who have what I'll call "short duration changes"
based on what's above, what are the things you worry about happening
if you go longer. Anyone who goes longer please also give your
philosophy.

Thanks,
z

On Mon, 15 Nov 2004 21:21:36 GMT, zatatime wrote:

I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

In the other threads it seems many have a higher frequency than this.
Would people chime in with how often calendar and flight time they
change? For those who have what I'll call "short duration changes"
based on what's above, what are the things you worry about happening
if you go longer. Anyone who goes longer please also give your
philosophy.

Thanks,
z

Aeroshell 15W50; 40-50 hrs or 4 months, which ever comes first. And it's
usually the 50 hrs.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

zatatime writes:

I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

In the other threads it seems many have a higher frequency than this.
Would people chime in with how often calendar and flight time they
change? For those who have what I'll call "short duration changes"
based on what's above, what are the things you worry about happening
if you go longer. Anyone who goes longer please also give your
philosophy.

I change it every 25 hours, both oil and filter. I read somewhere that
three months would be a good interval if you fly less than 25 hours
during that period. In my case, I seem to fly about 125 to 150 hours a
year, sometimes closer to 175, so I go through enough oil changes to
never exceed the three month rule.

Some might think I'm being overzealous, but factor in the oil change
cost into the total operating costs, and it's a pretty tiny amount,
particularly if you do your own changes.

-jav

I do mine in the Pitts about every 25 hours or six months. I'm probably
more rigorous about the 25 hours than the six months, but I never let it go
more than a year if I still havent reached the 25 hours. We didn't have a
very good summer so for that, and a few other reasons, I haven't flown much
in the last year. I haven't hit the 25 hours but if I exceed the 6 months,
I'll change it.

Now, as to why change it that often, I honestly can't remember the details.
but I remember reading in a couple of places, specfically in oil-related
documentation, that changing it that often was a good thing, so I just put
the times in my head and go with that.

Shawn
"zatatime" wrote in message
...
I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

In the other threads it seems many have a higher frequency than this.
Would people chime in with how often calendar and flight time they
change? For those who have what I'll call "short duration changes"
based on what's above, what are the things you worry about happening
if you go longer. Anyone who goes longer please also give your
philosophy.

Thanks,
z

zatatime wrote
I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

I think 50 hours is fine with a filter. When I had a plane with a
screen only, I went 25 - because the oil is not filtered as
efficiently and degrades faster. I have filters now so I shoot for
50. I don't mind going over if a trip runs long - I won't change it
on the road to keep from going over - but I've never gone to 60 and if
I know I'll go over a lot I'll change it early. I'll also change
early if I swapped a jug, because the breakin is hard on the oil.

I think the calendar period is an issue. Two things degrade oil -
heat and moisture. Heat comes from engine hours, but moisture comes
from sitting.

In the old days, 50 hours was considered fine for a screen, 100 for a
filter, and a year was no big deal. Paradoxically, the reason I think
this is no longer reasonable is that the oil is better.

It used to be that the oil degraded so quickly in use that keeping
'good' oil in the engine was not practical - you would have to change
the oil every 5-10 hours. After that - well, there wasn't that much
difference between the oil at 25 hours and 100. Of course back then,
engine TBO for the small fours was in the 1000 hour range. It's
double that now, and believe me it's nothing the engine manufacturers
changed in the design. It's mostly better lubricants.

These days, there is a LOT of difference between 25 and 100. There's
even a pretty significant difference between 50 and 100. Some people
change at 25-30 even with a filter, and while that's more often than
the engine manufacturers recommend, it's not really wrong. There is a
noticeable difference between 25 and 50. I'm just not convinced it
makes a real difference compared to the other factors involved.

Michael

zatatime wrote in message . ..
I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

The general recommendation for the average ContiLycosaurus is 25
hours if you have no filter, or 50 hrs. if you have one. I remember
reading a Lyc. manual or tech document that recommended a maximum of 4
months between changes. Presumably, this was to get rid of the
build-up of acids in the oil that are a byproduct of combustion.

John Galban=====N4BQ (PA28-180)

zatatime wrote:

In the other threads it seems many have a higher frequency than this.

I saw a Lycoming recommendation for the O-320 to change the oil at 50
hours or four months, whichever comes first. I think it's in the manual
for my engine.

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to
have
been looking for it.

"Michael" wrote in message
om...
zatatime wrote
I fly my bird about 50 hours per year. I was taught by an old-timer
that 50 hours was fine for oil changes and that a year was an
acceptable calendar period.

I think 50 hours is fine with a filter. When I had a plane with a
screen only, I went 25 - because the oil is not filtered as
efficiently and degrades faster. I have filters now so I shoot for
50. I don't mind going over if a trip runs long - I won't change it
on the road to keep from going over - but I've never gone to 60 and if
I know I'll go over a lot I'll change it early. I'll also change
early if I swapped a jug, because the breakin is hard on the oil.

I think the calendar period is an issue. Two things degrade oil -
heat and moisture. Heat comes from engine hours, but moisture comes
from sitting.

In the old days, 50 hours was considered fine for a screen, 100 for a
filter, and a year was no big deal. Paradoxically, the reason I think
this is no longer reasonable is that the oil is better.

It used to be that the oil degraded so quickly in use that keeping
'good' oil in the engine was not practical - you would have to change
the oil every 5-10 hours. After that - well, there wasn't that much
difference between the oil at 25 hours and 100. Of course back then,
engine TBO for the small fours was in the 1000 hour range. It's
double that now, and believe me it's nothing the engine manufacturers
changed in the design. It's mostly better lubricants.

These days, there is a LOT of difference between 25 and 100. There's
even a pretty significant difference between 50 and 100. Some people
change at 25-30 even with a filter, and while that's more often than
the engine manufacturers recommend, it's not really wrong. There is a
noticeable difference between 25 and 50. I'm just not convinced it
makes a real difference compared to the other factors involved.

Michael

Dont airplane oil filter have a by-pass in them so they dont filter 100% of
the oil?