Preheating engines: Airplane engines versus auto engines

[Peter R.]

This time of year here in the Northeast US I always preheat my Bonanza's
IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
sits in an unheated t-hangar. The result is that the oil temperature at
startup is around 105 degrees F, even if the outside air temperature is as
low as -15 degrees F.

Monday night I arrived at my t-hangar to discover that at some point during
the day the line person accidentally pulled out the plug connecting the Tanis
heater to the small extension cord I use to extend the plug to the outside of
the cowling cover, so the aircraft had not been preheating. Outside and
inside temperatures were both a cold 25 degrees F.

Given any other day, I would have plugged the aircraft back in and scrapped
the flight but in this case I had an Angel Flight patient waiting in another
city for my arrival and I was already late. Thus I made the painful decision
to start up the aircraft and allow it to low idle until the oil heated
thoroughly. A small consolation is that the engine had been recently filled
with fresh Exxon Elite oil. To my relief the aircraft started right up.

I know what I did has negative long term repercussions on my engine's health
and I have already derived a tool to lock the two cords and prevent this
accidental unplugging from happening again. However, this leads me to
question the differences between aircraft engines and auto engines:

Why is it that here in the Northeast US seemingly no one preheats their
automobile engine before start-up in very cold temperatures? Is the long-term
damage the same for both autos and aircraft engines? If so, why do you
suppose auto owners don't typically do this? Is it because that most auto
owners do not keep their cars very long?

--
Peter

[Paul Tomblin]

In a previous article, "Peter R." > said:
>Why is it that here in the Northeast US seemingly no one preheats their
>automobile engine before start-up in very cold temperatures? Is the long-term
>damage the same for both autos and aircraft engines? If so, why do you
>suppose auto owners don't typically do this? Is it because that most auto
>owners do not keep their cars very long?
>


Aircraft engines are air cooled, auto engines are liquid cooled.

The following is what I was told when I was driving a Volkswagen Beetle,
and the experts were saying that you needed to let the beast idle for at
least 5 minutes in the winter:

Liquid cooled engines stay in a very narrow temperature range while
operating, so are built with very tight tolerances, but air cooled engines
have more slop because they get both hotter and colder than liquid cooled
engines. Also, they are cooled primarily by the engine oil. Because of
that, you need to preheat the engine enough that the oil is spread around
and everything has warmed enough that the pistons are making good contact
with the cylinder walls.


--
Paul Tomblin > http://blog.xcski.com/
"The day Microsoft makes something that doesn't suck is probably the day they
start making vacuum cleaners" - Ernst Jan Plugge

[gpaleo]

"Peter R." > wrote
...
> ...........................................
>Outside and inside temperatures were both a cold 25 degrees F.
>
> Given any other day, I would have plugged the aircraft back in and
> scrapped
> the flight but in this case I had an Angel Flight patient waiting in
> another
> city for my arrival and I was already late. Thus I made the painful
> decision
> to start up the aircraft and allow it to low idle until the oil heated
> thoroughly. A small consolation is that the engine had been recently
> filled
> with fresh Exxon Elite oil. To my relief the aircraft started right up.
>
> I know what I did has negative long term repercussions on my engine's
> health
>.................................................. ....
> Peter



This is joke post, right????
You're killing your engine because you started it at 25
deg???????????????????????????????????
ROTFLMAO
I'm sorry, I'll shut up now.

[Robert M. Gary]

On Dec 19, 9:35 am, (Paul Tomblin) wrote:
> In a previous article, "Peter R." > said:
>
> >Why is it that here in the Northeast US seemingly no one preheats their
> >automobile engine before start-up in very cold temperatures? Is the long-term
> >damage the same for both autos and aircraft engines? If so, why do you
> >suppose auto owners don't typically do this? Is it because that most auto
> >owners do not keep their cars very long?
>
> Aircraft engines are air cooled, auto engines are liquid cooled.

That may affect the time it takes for the oil to heat up but certainly
both engines start at the same temp. I think the question relates to
the lubrication ability of sluggish oil at start. In addition, I'm not
sure that an aircraft engine at idle really displaces much more heat
than a car engine with the thermostat closed in the cold. How much air
really moves over the cylinders of an idling aircraft engine?

-robert

[Tauno Voipio]

Peter R. wrote:

--- clip clip --


> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?

Here in the north of Europe We'll pre-heat our cars if
possible, if the temperature goes below +5 C (whatever
it is in F, around 40?).

You can force an engine to start even at -30 C, but it
means that the poor thing runs some time practically
dry of lubrication.

--

Tauno Voipio (CPL(A), flying OH-PYM, PA28RT-201T)
tauno voipio at iki fi

[Jim Stewart]

Peter R. wrote:

> Given any other day, I would have plugged the aircraft back in and scrapped
> the flight but in this case I had an Angel Flight patient waiting in another
> city for my arrival and I was already late. Thus I made the painful decision
> to start up the aircraft and allow it to low idle until the oil heated
> thoroughly. A small consolation is that the engine had been recently filled
> with fresh Exxon Elite oil. To my relief the aircraft started right up.

I think you made the right judgment call.

The engine life is more dependent on your long-
term level of care than for a single instance
of pressing the limits.

BTW, a simple overhand knot in the power cord
where the heater plug and the extension cord
mate will prevent someone from inadvertently
unplugging them.

> I know what I did has negative long term repercussions on my engine's health
> and I have already derived a tool to lock the two cords and prevent this
> accidental unplugging from happening again. However, this leads me to
> question the differences between aircraft engines and auto engines:
>
> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?
>

[Peter R.]

On 12/19/2007 1:09:15 PM, Jim Stewart wrote:

> BTW, a simple overhand knot in the power cord
> where the heater plug and the extension cord
> mate will prevent someone from inadvertently
> unplugging them.

Unfortunately no room for an overhand knot. There is no slack at all in the
Tanis heater-side plug, as it is secured right at the plug to the (IIRC)
support that also holds the fuel lines.

--
Peter

[Peter R.]

On 12/19/2007 12:39:10 PM, "gpaleo" wrote:

> This is joke post, right????

Yes, it's a joke. You can go back to bed now.

--
Peter

[[email protected]]

On Dec 19, 12:21 pm, "Peter R." > wrote:
> This time of year here in the Northeast US I always preheat my Bonanza's
> IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
> sits in an unheated t-hangar. The result is that the oil temperature at
> startup is around 105 degrees F, even if the outside air temperature is as
> low as -15 degrees F.
>
> Monday night I arrived at my t-hangar to discover that at some point during
> the day the line person accidentally pulled out the plug connecting the Tanis
> heater to the small extension cord I use to extend the plug to the outside of
> the cowling cover, so the aircraft had not been preheating. Outside and
> inside temperatures were both a cold 25 degrees F.
>
> Given any other day, I would have plugged the aircraft back in and scrapped
> the flight but in this case I had an Angel Flight patient waiting in another
> city for my arrival and I was already late. Thus I made the painful decision
> to start up the aircraft and allow it to low idle until the oil heated
> thoroughly. A small consolation is that the engine had been recently filled
> with fresh Exxon Elite oil. To my relief the aircraft started right up.
>
> I know what I did has negative long term repercussions on my engine's health
> and I have already derived a tool to lock the two cords and prevent this
> accidental unplugging from happening again. However, this leads me to
> question the differences between aircraft engines and auto engines:
>
> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?
>
> --
> Peter

My understanding is that the _oil_ is different, not the engine. Most
piston aircraft engine oils gel at higher temperatures than do oils
for automotive engines. Or at least that is what I was told by my
instructor when I was training up in the high country.

Don't be relieved that the engine started. Be relieved that there
isn't anything ferrous in the oil screen next annual inspection.
Might ask your neighborhood FBO to use one of their portable heaters
next time around :-)

-Psy

[Peter R.]

On 12/19/2007 1:51:18 PM, " wrote:

> Might ask your neighborhood FBO to use one of their portable heaters
> next time around :-)

I have read in several different mags that those portable heaters only warm
the cylinders and not the bottom end (cam shaft) where the heated oil is most
important during the short time most FBOs run the units. Consequently it is
somewhat a waste of time and energy to use that type of heater.

--
Peter

[B A R R Y[_2_]]

Peter R. wrote:
> On 12/19/2007 1:51:18 PM, " wrote:
>
>> Might ask your neighborhood FBO to use one of their portable heaters
>> next time around :-)
>
> I have read in several different mags that those portable heaters only warm
> the cylinders and not the bottom end (cam shaft) where the heated oil is most
> important during the short time most FBOs run the units. Consequently it is
> somewhat a waste of time and energy to use that type of heater.
>


I use both.

I plug in the pan, while at the same time using a forced air unit.

[Matt Whiting]

Peter R. wrote:

> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?
>

Well, I make no claim to KNOW the answer, but I do have a few opinions
about it.

1. Auto engines have tighter tolerances as they are water cooled and
operate over a narrower and better controlled temperature range. They
can thus run thinner oil which starts to circulate much more quickly
than the molasses specified for most aircraft engines.

2. The consequences of engine damage in a car are much lower so it just
isn't worth the hassle of using an engine heater unless it is required
for the car to start.

3. This is a perpetuation of a decades old myth.

I personally believe that the above are weighted roughly as follows:

1. 30%
2. 10%
3. 60%

It would fun to have real data, but that would be very expensive and
time consuming to obtain. I've run many car engines well above 100,000
miles (roughly time equivalent to 2,000 hours, but not total power
produced equivalent to an airplane engine) with cold starts at least 5
months of the year and never had any indication of unusual engine wear.
I've NEVER yet worn out an auto engine in 30+ years of auto ownership.


Matt

[Matt Whiting]

Peter R. wrote:
> On 12/19/2007 12:39:10 PM, "gpaleo" wrote:
>
>> This is joke post, right????
>
> Yes, it's a joke. You can go back to bed now.
>

No, 6 year-olds should be in school by mid-day, not playing on mommies
computer!

[Matt Whiting]

Tauno Voipio wrote:
> Peter R. wrote:
>
> --- clip clip --
>
>
>> Why is it that here in the Northeast US seemingly no one preheats their
>> automobile engine before start-up in very cold temperatures? Is the
>> long-term
>> damage the same for both autos and aircraft engines? If so, why do you
>> suppose auto owners don't typically do this? Is it because that most auto
>> owners do not keep their cars very long?
>
> Here in the north of Europe We'll pre-heat our cars if
> possible, if the temperature goes below +5 C (whatever
> it is in F, around 40?).
>
> You can force an engine to start even at -30 C, but it
> means that the poor thing runs some time practically
> dry of lubrication.
>

Really? Where does all of the oil disappear to that was there when the
engine was shut down?

Matt

[[email protected]]

On Dec 19, 4:40 pm, Matt Whiting > wrote:
> Peter R. wrote:
> > Why is it that here in the Northeast US seemingly no one preheats their
> > automobile engine before start-up in very cold temperatures? Is the long-term
> > damage the same for both autos and aircraft engines? If so, why do you
> > suppose auto owners don't typically do this? Is it because that most auto
> > owners do not keep their cars very long?
>
> Well, I make no claim to KNOW the answer, but I do have a few opinions
> about it.
>
> 1. Auto engines have tighter tolerances as they are water cooled and
> operate over a narrower and better controlled temperature range. They
> can thus run thinner oil which starts to circulate much more quickly
> than the molasses specified for most aircraft engines.
>
> 2. The consequences of engine damage in a car are much lower so it just
> isn't worth the hassle of using an engine heater unless it is required
> for the car to start.
>
> 3. This is a perpetuation of a decades old myth.
>
> I personally believe that the above are weighted roughly as follows:
>
> 1. 30%
> 2. 10%
> 3. 60%
>
> It would fun to have real data, but that would be very expensive and
> time consuming to obtain. I've run many car engines well above 100,000
> miles (roughly time equivalent to 2,000 hours, but not total power
> produced equivalent to an airplane engine) with cold starts at least 5
> months of the year and never had any indication of unusual engine wear.
> I've NEVER yet worn out an auto engine in 30+ years of auto ownership.
>
> Matt

Matt's answer is right on. My experimental plane has a V-8 347 cu in
all aluminum water cooled engine in it. I keep it in a 50 f hangar, it
has a oil pan heater that cycles at 165 f and it loves it, I run 10-40
racing oil and the oil pressure comes right up on start up. Aircooled
engines spec 100w which is really straight 50 weight, the multi
viscosity aircraft oils are still alot thicker then automotive oils so
they take longer to suck up through the pick up tube and pressurize
the oil galley. As for the original poster I am sure he didn't do any
harm to his motor by starting it at 25 f.

Ben
www.haaspowerair.com

[[email protected]]

On Dec 19, 11:57 am, "Peter R." > wrote:
> On 12/19/2007 1:51:18 PM, " wrote:
>
> > Might ask your neighborhood FBO to use one of their portable heaters
> > next time around :-)
>
> I have read in several different mags that those portable heaters only warm
> the cylinders and not the bottom end (cam shaft) where the heated oil is most
> important during the short time most FBOs run the units. Consequently it is
> somewhat a waste of time and energy to use that type of heater.
>
> --
> Peter

If you heat the cylinders you'll heat the whole engine.
Metal conducts heat.

25°F isn't cold unless you're running heavy oil, like
W100. We run Aeroshell 15W50 year-round and sometimes start these
things at -10°C which is what? around 14°F? And the engines
(Lycomings) all reach TBO. No metal. We put cowl covers on them after
a flight when they're parked outside and start them later on at temps
to -25°C.

The big danger with cold oil is its reluctance to flow.
The oil pump has to suck the oil up from the sump, and cold oil gets
thick. It's like trying to suck a cold, thick milkshake through a
straw; you've all done that. The pump cannot create more than an
absolute vacuum, and if the oil is too thick the pump won't get much
and so the engine won't get it either. The cylinders don't mind
getting little, but the bearings need lots and so does the cam. Idling
too fast will cavitate the pump, delivering no or too little oil.
Idling too slow will throw too little oil on the cams and into the
cylinders. Can get tricky.

More likely damage is burning out starters from long
cranking. Or overpriming and flooding the engine. Or having it run
only briefly and quit, whereupon those cold sparkplugs will frost over
(H2O in the combustion byproducts) and the frost shorts them out. No
more spark. Burn out the starter trying to make it go. Starters have
no cooling system. Starter manufacturers say that a five-minute
cooldown is required after three ten-second cranks.
Kill the battery, and as the acid turns to water as it
discharges, the battery will now freeze (if it's cold enough and the
battery is dead enough and you leave it in the airplane) and split and
spill weakened acid everywhere. It'll still eat your airplane.

Cars typically use 5W30. I used to use 0W30 in my Ford
pickup. Started OK at -35°C. Airplane engines can't use such thin
stuff.

Dan

[Jay Honeck]

> Matt's answer is right on.

Ah, yes, the annual "Is it necessary to pre-heat?" thread. Soon to
be followed by the "Should I leave it plugged in all the time?"
discussion!

Just to get the ball rolling, we pre-heat Atlas whenever the temp is
below 40 degrees F. And, yes, we leave it plugged in all the time.
("It" being a Tanis oil pan and cylinder head heater with a quilted
nose cowl wrap to hold the heat in...)

Here's a pic of our cowl wrap, custom made by Mary from an old nylon
sleeping bag and a bunch of velcro:
http://tinyurl.com/2oj9g7

We fly at least weekly, so I don't worry about condensation. IMHO,
plugging in the heater immediately after shut-down should help to
prevent condensation from developing, since the engine never cools
back to ambient temperature before it's started and brought back up to
temperature at the next flight.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Dave[_3_]]

Hi Jay!

Kinda feels like the other "home" doesn't it !?

:)

Dave



On Wed, 19 Dec 2007 16:57:53 -0800 (PST), Jay Honeck
> wrote:

>> Matt's answer is right on.
>
>Ah, yes, the annual "Is it necessary to pre-heat?" thread. Soon to
>be followed by the "Should I leave it plugged in all the time?"
>discussion!
>
>Just to get the ball rolling, we pre-heat Atlas whenever the temp is
>below 40 degrees F. And, yes, we leave it plugged in all the time.
>("It" being a Tanis oil pan and cylinder head heater with a quilted
>nose cowl wrap to hold the heat in...)
>
>Here's a pic of our cowl wrap, custom made by Mary from an old nylon
>sleeping bag and a bunch of velcro:
>http://tinyurl.com/2oj9g7
>
>We fly at least weekly, so I don't worry about condensation. IMHO,
>plugging in the heater immediately after shut-down should help to
>prevent condensation from developing, since the engine never cools
>back to ambient temperature before it's started and brought back up to
>temperature at the next flight.

[Matt Whiting]

Jay Honeck wrote:
>> Matt's answer is right on.
>
> Ah, yes, the annual "Is it necessary to pre-heat?" thread. Soon to
> be followed by the "Should I leave it plugged in all the time?"
> discussion!

Almost as much fun as the "does it hurt your engine to practice
engine-out approaches."

:-)

Matt

[Dave[_3_]]

Four questions..

What weight of Oil?

What brand?

How long before the oil pressure came up?

How long since last run?

Preferred answers.

15/50, Aeroshell,less than 15 seconds, less than one week..

4 of 4.. no concern

1, 3 and 4 ...probably no concern

1 and 3, - might see aluminum spike a little in your next oil test

Single weight, brand "X", more than 15 seconds, more than 3 weeks..
Probably should not do this very often...

The above gleaned from others much more capable than I, and I chose
to listen when they speak..

YMMV!

Dave



On Wed, 19 Dec 2007 12:21:28 -0500, "Peter R." >
wrote:

>This time of year here in the Northeast US I always preheat my Bonanza's
>IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
>sits in an unheated t-hangar. The result is that the oil temperature at
>startup is around 105 degrees F, even if the outside air temperature is as
>low as -15 degrees F.
>
>Monday night I arrived at my t-hangar to discover that at some point during

[gpaleo]

"Matt Whiting" > wrote
...
>
> Peter R. wrote:
>> On 12/19/2007 12:39:10 PM, "gpaleo" wrote:
>>> This is joke post, right????
>>
>> Yes, it's a joke. You can go back to bed now.
>>
>
> No, 6 year-olds should be in school by mid-day, not playing on mommies
> computer!

As a 6 year-old mechanical engineer of some 30 years practice and owner of
an IO-540 equiped airplane, I find it somewhat disturbing that the OP was
NOT a joke.
Anyway, pat on the back - big hug time for the courageous aviator who
started his engine at **GASP** 25 F, after careful deliberation on aborting
the flight until Summer.
Catch my drift??

[Denny]

I purchased Fat Albert from an FBO who kept him in an unheated hangar
for 40 years, and never preheated unless it was well below zero
(that's in Farenheit, sonny)... Often it was a 3AM panic call from GM
who needed engine parts delivered to avoid the assembly plant from
shutting down and their truck was already on the way to the airport
with the parts....Load the plane, start the engines, hurry down the
taxiway checking mags while rolling, swing onto the runway, cob the
throttles and go... Elapsed running time from start to takeoff, less
than two minutes for the nearest runway, and perhaps three minutes for
the furthest... HIs engines routinely went to TBO...

While there is nothing wrong with preheat, etc. - there is also
nothing wrong with using synthetic oil and preheating only for extreme
temperatures... The biggest killer of aircraft engines is dry starts
from weeks/months of sitting between starts... Low temperature starts
on a well oiled engine have little to no impact on the wear cycle...
I use 15W50 in the winter and 100W+ in the summer... I do not preheat
unless it is below zero F... My starboard engine has 1700 hours since
factory zero and other than the oil burn being ~ 3 hours to the quart,
it starts and runs like a new engine... The port engine has 900 hours
since a field overhaul and it runs fine...

denny

[Paul kgyy]

>
> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?
>
> --
> Peter

Lycoming says you can start without preheat down in the teens if you
use multiviscosity oil. As others have said, one of the biggest
differences from auto use is that aero engines are often flown less
frequently so there's less oil hanging around at startup. On the
other hand, that's true even in warm weather, though warm oil will be
redistributed more quickly.

I doubt that you did any harm. Convert all the degrees to Kelvin
temps and be comforted :-)

[[email protected]]

On Dec 20, 6:04 am, Denny > wrote:
The biggest killer of aircraft engines is dry starts
> from weeks/months of sitting between starts...


That's one, but there's another bad one: Short flights,
especially in cold weather. byproducts of combustion include water
vapor, and some of that squeezes past the pistons and rings when the
engine is cold (some when it's hot, too, but much less so) and this
vapor condenses in the crankcase and ends up in the oil. If the engine
doesn't get hot enough for long enough, the water isn't boiled off and
will mix slowly with the oil, breaking it down and combining with
sulfur and chlorine and nitrogen to form sulfuric, hydrochloric and
nitric acids. These don't belong in your engine. The stuff that's left
from these reactions forms sludge and clogs up hydraulic lifters and
cakes on the inside of the case and soon enough breaks off and shows
up as scary black guck in the filter. The acids cause dissimilar metal
corrosion between the crank and cam and their bearings, between the
aluminum piston and the steel cylinder and rings, and on valve stems.
Bad. Corroded valve stems break and the engine tries to eat the valve
heads and gets indigestion.
The oil in my little old Continental doesn't get above
120°F on cold days. There's a tank blanket that I need to buy or make
to get it up. I just finished rebuilding the thing to fix corroded
bearings and seized valve lifters.

Dan

[Peter R.]

On 12/19/2007 7:56:55 PM, wrote:

> Cars typically use 5W30. I used to use 0W30 in my Ford
> pickup. Started OK at -35°C. Airplane engines can't use such thin
> stuff.

Thanks, Dan, for the education. Unlike some of the hotshot pilots in this
group who apparently were born with this knowledge, I admit to still having a
lot to learn despite flying twice to three times every week.

--
Peter

[Peter R.]

On 12/19/2007 9:40:19 PM, Dave wrote:

> What weight of Oil?

20w-50

> What brand?

Exxon Elite

> How long before the oil pressure came up?

Within a minute or so, I don't remember now.

> How long since last run?

This was Monday, aircraft last flown previous Saturday. Aircraft is flown
twice to three times every week.


--
Peter

[Peter R.]

On 12/20/2007 9:24:28 AM, Paul kgyy wrote:

> I doubt that you did any harm. Convert all the degrees to Kelvin
> temps and be comforted :-)

Ha. Thanks, Paul.

--
Peter

[Dave Anderer[_1_]]

On 2007-12-19 12:21:28 -0500, "Peter R." > said:

> Given any other day, I would have plugged the aircraft back in and scrapped
> the flight

> I know what I did has negative long term repercussions on my engine's health

I'm sure you must do some analysis in your head to judge the damage
inflicted on the engine in this case - otherwise, how could you judge
if scrapping a flight is the appropriate thing to do? I'm curious how
you quantify the 'long term repercussions'. Have you concluded, for
example, that not preheating in this case will:

- Reduce the TBO for your engine by 10 hours?
- Increase oil consumption by .2 qt/hour?
- Increase the risk of a catastrophic in-flight failure by 5%?

Clearly those are just some examples, but I would like to understand
what you have judged the impact of flying in this case would be.

[Matt W. Barrow]

"gpaleo" > wrote in message
news:1198154485.901022@athprx03...
> "Matt Whiting" > wrote
> ...
>> No, 6 year-olds should be in school by mid-day, not playing on mommies
>> computer!
>
> As a 6 year-old mechanical engineer of some 30 years practice and owner of
> an IO-540 equiped airplane, I find it somewhat disturbing that the OP was
> NOT a joke.
> Anyway, pat on the back - big hug time for the courageous aviator who
> started his engine at **GASP** 25 F, after careful deliberation on
> aborting the flight until Summer.
> Catch my drift??

Perhaps with your extensive and pontifical experience you cold summarize the
findings of Shell, Chevron, and TCM of the percentage of wear that occurs in
the first 30 seconds of cold (ie, below 40 degrees) starts?

[Matt W. Barrow]

"Peter R." > wrote in message
...
> On 12/19/2007 7:56:55 PM, wrote:
>
>> Cars typically use 5W30. I used to use 0W30 in my Ford
>> pickup. Started OK at -35°C. Airplane engines can't use such thin
>> stuff.
>
> Thanks, Dan, for the education. Unlike some of the hotshot pilots in this
> group who apparently were born with this knowledge, I admit to still
> having a
> lot to learn despite flying twice to three times every week.
>

FWIW - http://www.reiffpreheat.com/tbo.htm

And some magazine articles at
http://www.reiffpreheat.com/product.htm#Why_preheat

And a blog article about engine moisture after shutdown (and follow-up) at
http://www.reiffpreheat.com/product.htm#Why_preheat (2nd and 3rd down)

As always...YMMV.
--
Matt Barrow
Performance Homes, LLC.
Cheyenne, WY

[gpaleo]

"Matt W. Barrow" > wrote
...
>
>
> "gpaleo" > wrote in message
> news:1198154485.901022@athprx03...
>> "Matt Whiting" > wrote
>> ...
>>> No, 6 year-olds should be in school by mid-day, not playing on mommies
>>> computer!
>>
>> As a 6 year-old mechanical engineer of some 30 years practice and owner
>> of an IO-540 equiped airplane, I find it somewhat disturbing that the OP
>> was NOT a joke.
>> Anyway, pat on the back - big hug time for the courageous aviator who
>> started his engine at **GASP** 25 F, after careful deliberation on
>> aborting the flight until Summer.
>> Catch my drift??
>
> Perhaps with your extensive and pontifical experience you cold summarize
> the findings of Shell, Chevron, and TCM of the percentage of wear that
> occurs in the first 30 seconds of cold (ie, below 40 degrees) starts?


May I humbly pontificate that proper starting of engines (incorporating the,
appropriate for the temps and engine, oil) at 25F will NOT impact their
respective TBOs to any statistically significant degree.
I have many examples of this at the airports where I have been based and I
follow this practice on my own plane.

[Matt Whiting]

gpaleo wrote:
> "Matt Whiting" > wrote
> ...
>>
>> Peter R. wrote:
>>> On 12/19/2007 12:39:10 PM, "gpaleo" wrote:
>>>> This is joke post, right????
>>>
>>> Yes, it's a joke. You can go back to bed now.
>>>
>>
>> No, 6 year-olds should be in school by mid-day, not playing on mommies
>> computer!
>
> As a 6 year-old mechanical engineer of some 30 years practice and owner
> of an IO-540 equiped airplane, I find it somewhat disturbing that the OP
> was NOT a joke.
> Anyway, pat on the back - big hug time for the courageous aviator who
> started his engine at **GASP** 25 F, after careful deliberation on
> aborting the flight until Summer.
> Catch my drift??

He never said anything about "killing" his engine. He is certainly
worrying more than necessary, but that is no worse than your overly
melodramatic and condescending response. Actually, your response was
worse as his was made from ignorance and yours was intentional.

Matt

[Matt W. Barrow]

"gpaleo" > wrote in message
news:1198177392.30618@athprx03...
> "Matt W. Barrow" > wrote
> ...
>>
>>
>> "gpaleo" > wrote in message
>> news:1198154485.901022@athprx03...
>>> "Matt Whiting" > wrote
>>> ...
>>>> No, 6 year-olds should be in school by mid-day, not playing on mommies
>>>> computer!
>>>
>>> As a 6 year-old mechanical engineer of some 30 years practice and owner
>>> of an IO-540 equiped airplane, I find it somewhat disturbing that the OP
>>> was NOT a joke.
>>> Anyway, pat on the back - big hug time for the courageous aviator who
>>> started his engine at **GASP** 25 F, after careful deliberation on
>>> aborting the flight until Summer.
>>> Catch my drift??
>>
>> Perhaps with your extensive and pontifical experience you cold summarize
>> the findings of Shell, Chevron, and TCM of the percentage of wear that
>> occurs in the first 30 seconds of cold (ie, below 40 degrees) starts?
>
>
> May I humbly pontificate that proper starting of engines (incorporating
> the, appropriate for the temps and engine, oil) at 25F will NOT impact
> their respective TBOs to any statistically significant degree.

Well, your holiness, no one said anything about TBO.

> I have many examples of this at the airports where I have been based and I
> follow this practice on my own plane.

Since you blew in with your qualifications at the forefront, answer the
question and don't change the subject and go off on tangents (like TBO).

Also, see the references in my later reply to Peter R., and be aware that
anecdotal stories are pretty much useless.

[Matt Whiting]

Matt W. Barrow wrote:
> "Peter R." > wrote in message
> ...
>> On 12/19/2007 7:56:55 PM, wrote:
>>
>>> Cars typically use 5W30. I used to use 0W30 in my Ford
>>> pickup. Started OK at -35°C. Airplane engines can't use such thin
>>> stuff.
>> Thanks, Dan, for the education. Unlike some of the hotshot pilots in this
>> group who apparently were born with this knowledge, I admit to still
>> having a
>> lot to learn despite flying twice to three times every week.
>>
>
> FWIW - http://www.reiffpreheat.com/tbo.htm
>
> And some magazine articles at
> http://www.reiffpreheat.com/product.htm#Why_preheat
>
> And a blog article about engine moisture after shutdown (and follow-up) at
> http://www.reiffpreheat.com/product.htm#Why_preheat (2nd and 3rd down)
>
> As always...YMMV.

Yes, YMMV, especially when based on incomplete information. The first
reference above claims that "The specific heat of oil is at least four
to five times the specific heat of the metals in an engine," which
simply isn't accurate for aircraft. If you count only the steel in the
engine, then this is true, but a significant part of most aircraft
engines is aluminum and its Cp is about twice that of steel and thus
less then 2.5X different from oil rather than 4-5X.

I've read the "expert" commentary from Shell, Lycoming, Continental, and
other companies about this issue and they certainly make arguments that
sound logical on the surface. However, I live in a fairly cold climate
for at least 5 months of the year and have personally had engines that
were cold started at temps often below 0 F and occasionally below -20F
with not a single problem.

So, I still preheat given a choice, but I would not lose a second of
sleep over starting an airplane engine at any temperature at which it
would crank fast enough to start.


Matt

[Tauno Voipio]

Matt Whiting wrote:
> Tauno Voipio wrote:
>
>> Peter R. wrote:
>>
>> --- clip clip --
>>
>>
>>> Why is it that here in the Northeast US seemingly no one preheats their
>>> automobile engine before start-up in very cold temperatures? Is the
>>> long-term
>>> damage the same for both autos and aircraft engines? If so, why do you
>>> suppose auto owners don't typically do this? Is it because that most
>>> auto
>>> owners do not keep their cars very long?
>>
>>
>> Here in the north of Europe We'll pre-heat our cars if
>> possible, if the temperature goes below +5 C (whatever
>> it is in F, around 40?).
>>
>> You can force an engine to start even at -30 C, but it
>> means that the poor thing runs some time practically
>> dry of lubrication.
>>
>
> Really? Where does all of the oil disappear to that was there when the
> engine was shut down?
>
> Matt

The lubrication is based on fluid between the metal
surfaces. When the oil thickens enough, it will not
get to the small spaces between the metal surfaces.

--

Tauno Voipio

[gpaleo]

Ï "Matt W. Barrow" > Ýãñáøå óôï ìÞíõìá
...
>
>
> "gpaleo" > wrote in message
> news:1198177392.30618@athprx03...
>> "Matt W. Barrow" > wrote
>> ...
>>>
>>>
>>> "gpaleo" > wrote in message
>>> news:1198154485.901022@athprx03...
>>>> "Matt Whiting" > wrote
>>>> ...
.................................................. ...............................
>>> Perhaps with your extensive and pontifical experience you cold summarize
>>> the findings of Shell, Chevron, and TCM of the percentage of wear that
>>> occurs in the first 30 seconds of cold (ie, below 40 degrees) starts?
>>
>>
>> May I humbly pontificate that proper starting of engines (incorporating
>> the, appropriate for the temps and engine, oil) at 25F will NOT impact
>> their respective TBOs to any statistically significant degree.
>
> Well, your holiness, no one said anything about TBO.
>

I see what you mean. I intended to convey the idea that no damage would
occur to the engine resulting from the cold-ish starts within the time
period to overhaul.
Do find some inner peace, my son ;-)) (the holy-ness kicking in).

[Dave Stadt]

"Tauno Voipio" > wrote in message
...
> Matt Whiting wrote:
>> Tauno Voipio wrote:
>>
>>> Peter R. wrote:
>>>
>>> --- clip clip --
>>>
>>>
>>>> Why is it that here in the Northeast US seemingly no one preheats their
>>>> automobile engine before start-up in very cold temperatures? Is the
>>>> long-term
>>>> damage the same for both autos and aircraft engines? If so, why do you
>>>> suppose auto owners don't typically do this? Is it because that most
>>>> auto
>>>> owners do not keep their cars very long?
>>>
>>>
>>> Here in the north of Europe We'll pre-heat our cars if
>>> possible, if the temperature goes below +5 C (whatever
>>> it is in F, around 40?).
>>>
>>> You can force an engine to start even at -30 C, but it
>>> means that the poor thing runs some time practically
>>> dry of lubrication.
>>>
>>
>> Really? Where does all of the oil disappear to that was there when the
>> engine was shut down?
>>
>> Matt
>
> The lubrication is based on fluid between the metal
> surfaces. When the oil thickens enough, it will not
> get to the small spaces between the metal surfaces.
>
> --
>
> Tauno Voipio

Research will tell you the oil is allready there and being cold and thick it
tends to go nowhere and in fact does its job rather well. Many engines are
started a far colder temps regularly and suffer no damage and make TBO.
Far,far worse to let an engine sit.

[Mike Noel]

Isn't some of the problem with cold starts not necessarily oil related but
related to piston scuffing against the cylinder walls? The aluminum pistons
have a greater coefficient of expansion than the steel cylinders and the
pistons should become a looser fit at colder temps. I'm not sure how the
rings fit into the temperature equation.
--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel


"gpaleo" > wrote in message
news:1198154485.901022@athprx03...
> "Matt Whiting" > wrote
> ...
>>
>> Peter R. wrote:
>>> On 12/19/2007 12:39:10 PM, "gpaleo" wrote:
>>>> This is joke post, right????
>>>
>>> Yes, it's a joke. You can go back to bed now.
>>>
>>
>> No, 6 year-olds should be in school by mid-day, not playing on mommies
>> computer!
>
> As a 6 year-old mechanical engineer of some 30 years practice and owner of
> an IO-540 equiped airplane, I find it somewhat disturbing that the OP was
> NOT a joke.
> Anyway, pat on the back - big hug time for the courageous aviator who
> started his engine at **GASP** 25 F, after careful deliberation on
> aborting the flight until Summer.
> Catch my drift??

[Jay Somerset]

On Thu, 20 Dec 2007 19:39:17 GMT, Tauno Voipio
> wrote:

>Matt Whiting wrote:
>> Tauno Voipio wrote:
>>
>>> Peter R. wrote:
>>>
>>> --- clip clip --
>>>
>>>
>>>> Why is it that here in the Northeast US seemingly no one preheats their
>>>> automobile engine before start-up in very cold temperatures? Is the
>>>> long-term
>>>> damage the same for both autos and aircraft engines? If so, why do you
>>>> suppose auto owners don't typically do this? Is it because that most
>>>> auto
>>>> owners do not keep their cars very long?
>>>
>>>
>>> Here in the north of Europe We'll pre-heat our cars if
>>> possible, if the temperature goes below +5 C (whatever
>>> it is in F, around 40?).
>>>
>>> You can force an engine to start even at -30 C, but it
>>> means that the poor thing runs some time practically
>>> dry of lubrication.
>>>
>>
>> Really? Where does all of the oil disappear to that was there when the
>> engine was shut down?
>>
>> Matt
>
>The lubrication is based on fluid between the metal
>surfaces. When the oil thickens enough, it will not
>get to the small spaces between the metal surfaces.

Preheating a car at +5C is just ridiculous if you are using the proper
weight of motor oil. I might use a block heater if the temperatures
went below -20C, but not higher than that. Try using a good 10W30 oil
between +5 and -10, and perhaps a 5W30 below that. You won't damage
anything, and your engine will last longer than the body panels on the
car!
--
Jay (remove dashes for legal email address)

[Dave[_1_]]

>20w-50

Close enough
>

>
>Exxon Elite

Thattle do...
>
>> How long before the oil pressure came up?
>
>Within a minute or so, I don't remember now.


Watch this like a hawk on cold starts of any kind...15 secs is
marginal, 10 secs max preferred...

No pressure, shut it down....

>> How long since last run?

>
>This was Monday, aircraft last flown previous Saturday. Aircraft is flown
>twice to three times every week.

2 days since last?

No worries mate!

Fly on..... :)

(remember, I am not an AME...but I do listen a lot.. fortunate to
have a few near whom I believe to be knowledgeable in this area..
including a reputable engine builder / overhauler..)

Cheers!

Dave

[Peter R.]

On 12/20/2007 9:15:15 PM, Dave wrote:

> Watch this like a hawk on cold starts of any kind...15 secs is
> marginal, 10 secs max preferred...

Will pay better attention to this. Thanks.

--
Peter

[[email protected]]

Preheating a car at +5C is just ridiculous if you are using the
proper
> weight of motor oil. I might use a block heater if the temperatures
> went below -20C, but not higher than that. Try using a good 10W30 oil
> between +5 and -10, and perhaps a 5W30 below that. You won't damage
> anything, and your engine will last longer than the body panels on the
> car!

I use 5W30 year-round in my '01 Chevy. Runs just fine, and
it's what the manufacturer recommends for our climate. The tolerances
in these auto engines are now so small that anything heavier is not
only a waste of time but could be really bad in the cold.
Aircraft engines have much larger tolerances, mostly because
they're air-cooled and get a lot hotter, with clearances between
things like aluminum pistons and steel cylinders getting pretty tight
at high temps. Aluminum expands at twice the rate of steel, and while
some pistons have steel inserts cast into them to control that
expansion, they still expand a lot. Liquid-cooled engines can be built
much tighter. And auto engines have much smaller cylinders than
aircraft engines of the same HP and so the overall expansion is less.
Rings are either chomed steel or cast iron and will expand at around
the same rate as the cylinder, but they'll still get tighter from the
heat draining off the piston through them. They have a bit of
difficulty getting rid of that heat through the microscopic oil film
on the cylinder wall.
With larger tolerances, more oil escapes. With larger
tolerances, the arc of contact area is shorter. With larger
tolerances, things tend to strike each other harder. So heavier oils
are necessary to slow the oil's escape from bearings and so on,
heavier to lubricate the shorter contact arcs, heavier to dampen the
shocks of parts banging into other parts.
Piston scuffing often happens when an engine is driven to full
power too soon. Pistons get hot and cylinders are still cool,
clearances disappear. Scuffing can happen if the oil isn't reaching
the cylinders, and since it's usually thrown off the rods (some
engines have a squirt hole in the rod opposite), a really low idle
might leave the cylinders dry. Some two-strokes like the aircooled
Rotaxes must be warmed up thoroughly or they'll seize soon after
takeoff. Local guy learned that the hard way. Seized it twice before
someone clued him in.

Best things for folks who fly infrequently include installing
a preoiler and don't make short flights. The preoiler will fill all
the oil galleries and pressure will come up even before start. The
short flights leave water in the oil the eat the engine. The folks who
"run it up once in a while to keep it healthy" without flying it are
doing the worst damage by far.

Dan

[nrp]

A key to lubrication of any aircraft engine is how soon an oil fog can
be established in a crankcase. This takes a while - especially if the
oil is thick, as the bearing journal clearances are not that great and
the amount of oil thrown from them is minimal given starting oil
viscosity and the comparatively low crankcase activity at low rpm.
Most of the oil flow generated by that fixed volume oil pump ends up
blowing over the relief valve and dropping directly back to the sump,
giving the oil little access to the heat of the engine pistons and
cylinder heads. There are no features on the rotating machinery that
will centrifugally splatter oil blobs onto the cam surfaces. They
have to depend on previous operation for lubrication until the fog
gets more generally developed.

Oil viscosity can easily vary over a 100:1 range between moderately
cold start and normal operating values. The leakage from a journal
bearing will correspond inversely as that viscosity and directly as
the cube of the bearing clearance - which is also compromised by the
differential thermal expansion of aluminum vs steel.

Remember it isn't the bearings - it is all the expensive surfaces in
your engine that are starved in a cold start. And the operating
profile is almost always a full takeoff power after only a few minutes
of operation.

I do agree though that the OP didn't do any substantial damage to his
engine since it had been run so recently and since it has
Continental's bottom-of-the-crankcase camshaft.

[Stealth Pilot[_2_]]

On Thu, 20 Dec 2007 21:43:18 +0200, "gpaleo" >
wrote:

>
>Ï "Matt W. Barrow" > Ýãñáøå óôï ìÞíõìá
...
>>
>>
>> "gpaleo" > wrote in message
>> news:1198177392.30618@athprx03...
>>> "Matt W. Barrow" > wrote
>>> ...
>>>>
>>>>
>>>> "gpaleo" > wrote in message
>>>> news:1198154485.901022@athprx03...
>>>>> "Matt Whiting" > wrote
>>>>> ...
>.................................................. ..............................
>>>> Perhaps with your extensive and pontifical experience you cold summarize
>>>> the findings of Shell, Chevron, and TCM of the percentage of wear that
>>>> occurs in the first 30 seconds of cold (ie, below 40 degrees) starts?
>>>
>>>
>>> May I humbly pontificate that proper starting of engines (incorporating
>>> the, appropriate for the temps and engine, oil) at 25F will NOT impact
>>> their respective TBOs to any statistically significant degree.
>>
>> Well, your holiness, no one said anything about TBO.
>>
>
>I see what you mean. I intended to convey the idea that no damage would
>occur to the engine resulting from the cold-ish starts within the time
>period to overhaul.
>Do find some inner peace, my son ;-)) (the holy-ness kicking in).

I'm stuffed if I can see how the cold start will have ruined his
engine.
the traditional reason for warming an engine prior to flight is so
that the exhaust muffle is hot enough to deliver carby heat if needed
on climb out.
now if the engine is fuel injected....
all engines get some wear in the first 30 seconds until all the oil is
around the sliding surfaces but for heavens sake the engine us not
running under any load so the wear will be minimal!

humble little I only run an O-200 in a Wittman Tailwind. I can be
airborne in under a minute from a cold start my hangar is so close to
the runway end. if I do take off with a cold engine and I dont
encounter icing my worst worry is a little blowby spraying some oil
mist under the belly which resolves in very short time as the parts
come to working temperatures. I just stick some new oil in :-)

one of the hardest things for an owner is to develop enough experience
with hands on operation to know the *actual* relative importances of
the concepts of engine operation. from my experience gpaleo is bang on
the money ....and I'm an atheist :-).

when it is all said and done...
there is more said than done.

Stealth Pilot
Australia

[Stealth Pilot[_2_]]

On Thu, 20 Dec 2007 08:21:32 -0800 (PST),
wrote:

>On Dec 20, 6:04 am, Denny > wrote:
> The biggest killer of aircraft engines is dry starts
>> from weeks/months of sitting between starts...
>
>
> That's one, but there's another bad one: Short flights,
>especially in cold weather. byproducts of combustion include water
>vapor, and some of that squeezes past the pistons and rings when the
>engine is cold (some when it's hot, too, but much less so) and this
>vapor condenses in the crankcase and ends up in the oil. If the engine
>doesn't get hot enough for long enough, the water isn't boiled off and
>will mix slowly with the oil, breaking it down and combining with
>sulfur and chlorine and nitrogen to form sulfuric, hydrochloric and
>nitric acids. These don't belong in your engine. The stuff that's left
>from these reactions forms sludge and clogs up hydraulic lifters and
>cakes on the inside of the case and soon enough breaks off and shows
>up as scary black guck in the filter. The acids cause dissimilar metal
>corrosion between the crank and cam and their bearings, between the
>aluminum piston and the steel cylinder and rings, and on valve stems.
>Bad. Corroded valve stems break and the engine tries to eat the valve
>heads and gets indigestion.
> The oil in my little old Continental doesn't get above
>120°F on cold days. There's a tank blanket that I need to buy or make
>to get it up. I just finished rebuilding the thing to fix corroded
>bearings and seized valve lifters.
>
> Dan

as a matter of deep religious significance, once your engine is warm
start the clock and dont land until an hour is up at least.

in the depths of winter remember that some parts of the world need
global warming :-)

now to be serious...
squeezing past the rings probably contributes a millionth of one
poofteenth of a percent to the problem.
when the crankcase cools there is moist external air sucked into the
cavity of the case through the crankcase breather. the moisture
condenses onto the cold internal surfaces of the engine.
can you please factor that into the alchemy above? it probably does
the damage occurring between the poofteenth of your scenario and the
100%.

now if you really want scarey black gunk try taking off the oil
reservoir and cleaning it out.

honestly you must lay awake sleepless at night :-)

Stealth (the O-200 is king) Pilot

[Stan Prevost[_1_]]

Peter, this thread has grown way too long and ****y for me to go check if
you already have received this info, so please excuse any duplication. Mike
Noel hit on an important factor that did not seem to be followed up on about
a difference between aircraft and automobile piston engines. See the papers
at http://www.tanisaircraft.com/articlesresearch.html .

Stan


"Peter R." > wrote in message
...
> This time of year here in the Northeast US I always preheat my Bonanza's
> IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
> sits in an unheated t-hangar. The result is that the oil temperature at
> startup is around 105 degrees F, even if the outside air temperature is as
> low as -15 degrees F.
>
> Monday night I arrived at my t-hangar to discover that at some point
> during
> the day the line person accidentally pulled out the plug connecting the
> Tanis
> heater to the small extension cord I use to extend the plug to the outside
> of
> the cowling cover, so the aircraft had not been preheating. Outside and
> inside temperatures were both a cold 25 degrees F.
>
> Given any other day, I would have plugged the aircraft back in and
> scrapped
> the flight but in this case I had an Angel Flight patient waiting in
> another
> city for my arrival and I was already late. Thus I made the painful
> decision
> to start up the aircraft and allow it to low idle until the oil heated
> thoroughly. A small consolation is that the engine had been recently
> filled
> with fresh Exxon Elite oil. To my relief the aircraft started right up.
>
> I know what I did has negative long term repercussions on my engine's
> health
> and I have already derived a tool to lock the two cords and prevent this
> accidental unplugging from happening again. However, this leads me to
> question the differences between aircraft engines and auto engines:
>
> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the
> long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?
>
> --
> Peter

[Matt Whiting]

Stealth Pilot wrote:

> I'm stuffed if I can see how the cold start will have ruined his
> engine.
> the traditional reason for warming an engine prior to flight is so
> that the exhaust muffle is hot enough to deliver carby heat if needed
> on climb out.

That's pretty funny. A preheat has so little affect on the temperature
of the exhaust muff that it isn't even a consideration. Within 10
seconds of engine start, the heat of the exhaust pipe will be at roughly
the same value whether the engine was started at 20 degrees F or 80
degrees F.

Matt

[Matt Whiting]

Tauno Voipio wrote:
> Matt Whiting wrote:
>> Tauno Voipio wrote:
>>
>>> Peter R. wrote:
>>>
>>> --- clip clip --
>>>
>>>
>>>> Why is it that here in the Northeast US seemingly no one preheats their
>>>> automobile engine before start-up in very cold temperatures? Is the
>>>> long-term
>>>> damage the same for both autos and aircraft engines? If so, why do you
>>>> suppose auto owners don't typically do this? Is it because that most
>>>> auto
>>>> owners do not keep their cars very long?
>>>
>>>
>>> Here in the north of Europe We'll pre-heat our cars if
>>> possible, if the temperature goes below +5 C (whatever
>>> it is in F, around 40?).
>>>
>>> You can force an engine to start even at -30 C, but it
>>> means that the poor thing runs some time practically
>>> dry of lubrication.
>>>
>>
>> Really? Where does all of the oil disappear to that was there when
>> the engine was shut down?
>>
>> Matt
>
> The lubrication is based on fluid between the metal
> surfaces. When the oil thickens enough, it will not
> get to the small spaces between the metal surfaces.
>

There was oil in those spaces when the engine was shut down and it
doesn't magically disappear. Most engines will run for some time with
no oil pressure and without damage.

Matt

[Matt Whiting]

Stan Prevost wrote:
> Peter, this thread has grown way too long and ****y for me to go check
> if you already have received this info, so please excuse any
> duplication. Mike Noel hit on an important factor that did not seem to
> be followed up on about a difference between aircraft and automobile
> piston engines. See the papers at
> http://www.tanisaircraft.com/articlesresearch.html .

Even more interesting is that Tanis leaves such obsolete information on
their web site. Take a magnet to a few car dealerships and see how many
engine blocks are cast iron these days...


Matt

[[email protected]]

On Dec 21, 4:45 am, Stealth Pilot >
wrote:

> squeezing past the rings probably contributes a millionth of one
> poofteenth of a percent to the problem.
> when the crankcase cools there is moist external air sucked into the
> cavity of the case through the crankcase breather. the moisture
> condenses onto the cold internal surfaces of the engine.
> can you please factor that into the alchemy above? it probably does
> the damage occurring between the poofteenth of your scenario and the
> 100%.

Nope. We have taken rocker covers off engines immediately
after a runup of a brand-new engine and found copious amounts of water
in them. The blowby of any cold engine is significant. If we briefly
run up an engine that has sat all night in a heated hangar and in our
very dry winter climate, we will find water on the dipstick every
time, with the engine at any point in its life. And the dipstick was
dry beforehand.
We operate on the western Canadian prairies where the air is
drier that where I grew up in south-central BC, which is the northern
tip of the Sonora Desert. We get little rain and snow here. Temps
reach -40C, more typically -20C, no fog and clear skies most of the
winter. It's REALLY dry, and any air sucked into these engines after
shutdown doesn't have enough moisture to make a couple of tears.

Dan

[nrp]

Air doesn't come into the crankcase via the breather - rather
combustion products that leak past the rings vent out thru the
breather. Burning hydrocarbons generate CO2 and water. The net dew
point of combustion and blowby products is about 180 degF. The water
will condense in cooler sections of the crankcase. It is this water
that causes most corrosion - especially after combining with nitrogen
oxides and sulfur oxides which make acid.

Crankcase condensation happens from engine operation - not from just
sitting around. The real trick is to ventilate these residual
combustion products from the crankcase immediately after shutdown
before they all condense. Systems are now starting to be sold which
actively do this.

A lot of this moisture accumulation problem would go away if aircraft
engines had a positive crankcase ventilation (PCV) system like car
engines now do, but they don't for whatever reason. I suspect part of
the reason car engines now last so much longer is due to the PCV
system.

[[email protected]]

On Dec 21, 1:39 pm, nrp > wrote:
> Air doesn't come into the crankcase via the breather - rather
> combustion products that leak past the rings vent out thru the
> breather. Burning hydrocarbons generate CO2 and water. The net dew
> point of combustion and blowby products is about 180 degF. The water
> will condense in cooler sections of the crankcase. It is this water
> that causes most corrosion - especially after combining with nitrogen
> oxides and sulfur oxides which make acid.
>
> Crankcase condensation happens from engine operation - not from just
> sitting around. The real trick is to ventilate these residual
> combustion products from the crankcase immediately after shutdown
> before they all condense. Systems are now starting to be sold which
> actively do this.
>
> A lot of this moisture accumulation problem would go away if aircraft
> engines had a positive crankcase ventilation (PCV) system like car
> engines now do, but they don't for whatever reason. I suspect part of
> the reason car engines now last so much longer is due to the PCV
> system.

Part of the problem is the water mixed with the oil; it's
reluctant to evaporate when it's like that. Running the engine long
enough to give it time to boil out is the best thing, and a PCV system
would surely help.
Proof of water as a combustion byproduct can be noted in
colder climates. If the breather tube is not drilled with a relief
hole partway up from its exit, it's liable to freeze up in cold
weather as the moisture that's constantly leaving the tube freezes at
the exit and plugs it. Then the pressure builds in the case and blows
the front seal out, scaring the daylights out of the pilot as oil
covers the windscreen. Some operators insulate that tube as well to
keep the gases hot enough to keep that exit open.
When we bring the airplanes in after operating in cold
weather, oil and water emulsion will be found on the floor under the
breather tube the next morning. That water wasn't sucked into the
engine as it cooled off. The engine's internal volume might be two or
three cubic feet, and if the air in there contracts by even 30%, that
little bit isn't going to pull in much moisture. It becomes a bigger
problem in wet climates and repeated warming/cooling cycles, as an
airplane sits outside for months on end and gets warm in the sun and
cools off at night. The same phenomenon puts water in your fuel tanks.

Dan

[nrp]

There's probably no more than about 1 cu ft of volume in a typical
crankcase. Even so that will contain on the order of half to one shot
glass full of water on shutdown. This will almost entirely condense
out as the crankcase is cooled to room temperature.

There is a slight amount of in-out-in of surrounding atmospheric
humidity with temperature, but the amount of water contained in that
air is trivial compared to that generated or left over by the products
of combustion.

[[email protected]]

On Dec 21, 2:39*pm, nrp > wrote:
> Air doesn't come into the crankcase via the breather - rather
> combustion products that leak past the rings vent out thru the
> breather. *

It seems to me that the air in the crancase is about 250 deg F
typically, since the pistons and such are hotter than the oil. That
means the partial pressure inside the crankcase decreases as the
engine cools, and the pressure drops, according to the equation Pv=RT.
As the pressure drops inside, the air outside has to enter the
crankcase to equalize the pressure, correct? With the air temp as much
as 200 deg higher inside the engine as outside, that means that a
volume of about half the crankcase of outside air ENTERS the crankcase
during the pressure equalization process. At least that is the way it
seems to me.

Bud

[nrp]

"As the pressure drops inside, the air outside has to enter the
crankcase to equalize the pressure, correct? With the air temp as much
as 200 deg higher inside the engine as outside, that means that a
volume of about half the crankcase of outside air ENTERS the crankcase
during the pressure equalization process. At least that is the way it
seems to me."

But it isn't air in the crankcase during engine operation. It is a
mixture of CO2 and water vapor. Outside air will re-enter only when
the water vapor condenses after shutdown. The amount of water vapor
in the comparatively cool outside air being drawn in is one or two
orders of magnitude less than that in the hot crankcase.

[WJRFlyBoy]

On Wed, 19 Dec 2007 12:21:28 -0500, Peter R. wrote:

> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?

No because it is entirely unnecessary.
--
Remove numbers for gmail and for God's sake it ain't "gee" either!

[Mike Spera]

> When we bring the airplanes in after operating in cold
> weather, oil and water emulsion will be found on the floor under the
> breather tube the next morning.
>
>

I suspect that the puddles have more to do with the fact that breather
outlets tend to be on the top of the engine and are connected to a 3
foot tube running straight down than any gasses purging out of the
crankcase at shutdown (or what the temperature was outside). The tube
walls are coated with a water/oil mix from flight and slowly this drips
down to cause the puddle.

An interesting test would be to remove the breather tubes completely
after flight and see if anything accumulates.

Good Luck,
Mike

[Mike Gilmour]

"Peter R." > wrote in message
...
> This time of year here in the Northeast US I always preheat my Bonanza's
> IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
> sits in an unheated t-hangar. The result is that the oil temperature at
> startup is around 105 degrees F, even if the outside air temperature is as
> low as -15 degrees F.
>
> Monday night I arrived at my t-hangar to discover that at some point
> during
> the day the line person accidentally pulled out the plug connecting the
> Tanis
> heater to the small extension cord I use to extend the plug to the outside
> of
> the cowling cover, so the aircraft had not been preheating. Outside and
> inside temperatures were both a cold 25 degrees F.
>
> Given any other day, I would have plugged the aircraft back in and
> scrapped
> the flight but in this case I had an Angel Flight patient waiting in
> another
> city for my arrival and I was already late. Thus I made the painful
> decision
> to start up the aircraft and allow it to low idle until the oil heated
> thoroughly. A small consolation is that the engine had been recently
> filled
> with fresh Exxon Elite oil. To my relief the aircraft started right up.
>
> I know what I did has negative long term repercussions on my engine's
> health
> and I have already derived a tool to lock the two cords and prevent this
> accidental unplugging from happening again. However, this leads me to
> question the differences between aircraft engines and auto engines:
>
> Why is it that here in the Northeast US seemingly no one preheats their
> automobile engine before start-up in very cold temperatures? Is the
> long-term
> damage the same for both autos and aircraft engines? If so, why do you
> suppose auto owners don't typically do this? Is it because that most auto
> owners do not keep their cars very long?
>
> --
> Peter

I've been more cautious about rapid heating up of engines since I
unfortunately split the engine block of my Jaguar XJ6 4.2 litre that I
conclude was caused by immediate rapid driving from -5c being late for an
appointment. Guess that expensive incident will always stay in my mind...

Mike

[Matt Whiting]

Mike Gilmour wrote:
> "Peter R." > wrote in message
> ...
>> This time of year here in the Northeast US I always preheat my Bonanza's
>> IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
>> sits in an unheated t-hangar. The result is that the oil temperature at
>> startup is around 105 degrees F, even if the outside air temperature is as
>> low as -15 degrees F.
>>
>> Monday night I arrived at my t-hangar to discover that at some point
>> during
>> the day the line person accidentally pulled out the plug connecting the
>> Tanis
>> heater to the small extension cord I use to extend the plug to the outside
>> of
>> the cowling cover, so the aircraft had not been preheating. Outside and
>> inside temperatures were both a cold 25 degrees F.
>>
>> Given any other day, I would have plugged the aircraft back in and
>> scrapped
>> the flight but in this case I had an Angel Flight patient waiting in
>> another
>> city for my arrival and I was already late. Thus I made the painful
>> decision
>> to start up the aircraft and allow it to low idle until the oil heated
>> thoroughly. A small consolation is that the engine had been recently
>> filled
>> with fresh Exxon Elite oil. To my relief the aircraft started right up.
>>
>> I know what I did has negative long term repercussions on my engine's
>> health
>> and I have already derived a tool to lock the two cords and prevent this
>> accidental unplugging from happening again. However, this leads me to
>> question the differences between aircraft engines and auto engines:
>>
>> Why is it that here in the Northeast US seemingly no one preheats their
>> automobile engine before start-up in very cold temperatures? Is the
>> long-term
>> damage the same for both autos and aircraft engines? If so, why do you
>> suppose auto owners don't typically do this? Is it because that most auto
>> owners do not keep their cars very long?
>>
>> --
>> Peter
>
> I've been more cautious about rapid heating up of engines since I
> unfortunately split the engine block of my Jaguar XJ6 4.2 litre that I
> conclude was caused by immediate rapid driving from -5c being late for an
> appointment. Guess that expensive incident will always stay in my mind...

No, that was caused by driving a Jaguar...

Matt

[Mike Spera]

>
> I've been more cautious about rapid heating up of engines since I
> unfortunately split the engine block of my Jaguar XJ6 4.2 litre that I
> conclude was caused by immediate rapid driving from -5c being late for an
> appointment. Guess that expensive incident will always stay in my mind...
>

My guess would be that the very cold temps caused the block to split due
to the coolant freezing over night. If it was -5C when you started it,
chances are it was much colder at some point in the evening.

Common in the upper Midwestern US was to see 70's era cars blow out
freeze plugs and/or crack blocks by running no (or too weak) antifreeze.
A cold start and immediate run up to high speed should not cause
catastrophic failure of a block. Being a Jag, it may have had a badly
cast block since new. Their QC ain't the best.

Good Luck,
Mike

[[email protected]]

On Dec 22, 6:43 am, Mike Spera > wrote:
> > When we bring the airplanes in after operating in cold
> > weather, oil and water emulsion will be found on the floor under the
> > breather tube the next morning.
>
> I suspect that the puddles have more to do with the fact that breather
> outlets tend to be on the top of the engine and are connected to a 3
> foot tube running straight down than any gasses purging out of the
> crankcase at shutdown (or what the temperature was outside). The tube
> walls are coated with a water/oil mix from flight and slowly this drips
> down to cause the puddle.
>
> An interesting test would be to remove the breather tubes completely
> after flight and see if anything accumulates.
>
> Good Luck,
> Mike

That's what I meant. It's not any gases coming out after
shutdown; it's the thickened oil, containing water, that hangs in that
cold breather tube and drips out slowly overnight in the heated
hangar. The water in the emulksion came from combustion blowby.

Dan

[Mike Spera]

>>
>>I suspect that the puddles have more to do with the fact that breather
>>outlets tend to be on the top of the engine and are connected to a 3
>>foot tube running straight down than any gasses purging out of the
>>crankcase at shutdown (or what the temperature was outside). The tube
>>walls are coated with a water/oil mix from flight and slowly this drips
>>down to cause the puddle.
>>
>>An interesting test would be to remove the breather tubes completely
>>after flight and see if anything accumulates.
>>
>>Good Luck,
>>Mike
>
>
> That's what I meant. It's not any gases coming out after
> shutdown; it's the thickened oil, containing water, that hangs in that
> cold breather tube and drips out slowly overnight in the heated
> hangar. The water in the emulksion came from combustion blowby.
>
> Dan

Sorry Dan, That thread was so screwed up I could not tell if you were in
the "it blows out after shutdown" or the "it sucks in after shutdown"
group. I'm not sure the breather tube needs to be in the cold. My
Cherokee drips whether it is 0 or 90 outside.
Mike

[[email protected]]

On Dec 21, 11:38*pm, nrp > wrote:
> *"As the pressure drops inside, the air outside has to enter the
> crankcase to equalize the pressure, correct? With the air temp as much
> as 200 deg higher inside the engine as outside, that means that a
> volume of about half the crankcase of outside air ENTERS the crankcase
> during the pressure equalization process. At least that is the way it
> seems to me."




>
> But it isn't air in the crankcase during engine operation. *It is a
> mixture of CO2 and water vapor. *

Well OK. The gas law of PV=nRT is true for all gases. All of them.
The point is that the engine does inhale (for the lack of a better
word) a significant volume of air from outside as it cools down. This
is a well known process. This air contains moisture. The oxidation
process (rusting) of the engine parts is galvanic corrosion and all it
needs is a molecular thin layer of moisture on the surface of say the
cam lobe. The total amount of water needed to cause this process is
miniscule. What prevents it from rusting your engine parts is the
layer of oil on them. Regular running of the engine replenishes this
layer of oil. This is what is important.

>Outside air will re-enter only when
>the water vapor condenses after shutdown.

The air enters as the pressure drops when the GAS inside the crankcase
cools. Condensation has nothing to do with it. If there were no
moisture in the gas contained in the crankcase at all, none, at
shutdown, the engine would still injest much more than enough moisture
than necessary to cause problems as it cools down. Condensation is
only only something else that happens along with the heat loss.

>The amount of water vapor
>in the comparatively cool outside air being drawn in is one or two
>orders of magnitude less than that in the hot crankcase.

The point is that you can fly all you want and remove all the water
from the oil that exists. You will still get plenty of moisture inside
the engine as it sits idle just from the outside air it injests as it
cools. Even barometric pressure changes as the weather passes by is
enough to cause engine corrosion.
Many pilots seem to believe that blow-by in the engine is a
normal operating condition. My experience( and opinion) and that of
many other race engine mechanics that I have talked to, is that once
combustion gases begin to leak past the rings, the end of that engine
is imminent and soon. Very soon. Blowby totally destroys the
lubrication of the piston in the area of the blowby, and it shouldn't
take a rocket scientist to know what that means.

regards,
Bud

[[email protected]]

On Dec 22, 6:15 pm, wrote:

> Many pilots seem to believe that blow-by in the engine is a
> normal operating condition. My experience( and opinion) and that of
> many other race engine mechanics that I have talked to, is that once
> combustion gases begin to leak past the rings, the end of that engine
> is imminent and soon. Very soon. Blowby totally destroys the
> lubrication of the piston in the area of the blowby, and it shouldn't
> take a rocket scientist to know what that means.
>
> regards,
> Bud

My experience is as an aircraft mechanic. Part of the
inspection process is the differential compression test on each
cylinder, when it's hot after shutdown. All cylinders leak a small
amount past the rings, and when the engine cools the leakage is
considerably worse. All rings have ring gaps, and unless you have
stacked rings (two rings in the same groove) you cannot stop the
leakage. Aircraft engines do not have stacked rings.
The fact that a frozen-shut breather will cause the front seal
to blow out is enough evidence that rings leak.
The volume of the crankcase, as noted earlier, is very small.
The amount of water in a cubic foot of air, even if it's saturated, is
miniscule compared to that which gets past the rings curing
combustion, unless the aircraft is parked for a long time and the
heating/cooling cycles of day/night pump air in and out repeatedly for
a long time. Water, even a small amount, mixes with oil and in the
presence of metal, which acts as a catalyst, breaks the oil down and
creates acids. The thin film of oil on the parts is the first
contributor to this process and is not much protection at all.

[Mike Gilmour]

"Mike Spera" > wrote in message
...
>
>>
>> I've been more cautious about rapid heating up of engines since I
>> unfortunately split the engine block of my Jaguar XJ6 4.2 litre that I
>> conclude was caused by immediate rapid driving from -5c being late for an
>> appointment. Guess that expensive incident will always stay in my mind...
>>
>
> My guess would be that the very cold temps caused the block to split due
> to the coolant freezing over night. If it was -5C when you started it,
> chances are it was much colder at some point in the evening.
>
> Common in the upper Midwestern US was to see 70's era cars blow out freeze
> plugs and/or crack blocks by running no (or too weak) antifreeze. A cold
> start and immediate run up to high speed should not cause catastrophic
> failure of a block. Being a Jag, it may have had a badly cast block since
> new. Their QC ain't the best.
>
> Good Luck,
> Mike

Mike, the coolant was at the correct winter dilution so I don't think
freezing was a contributory factor. More likely sloppy engineering standards
which similarly and sadly led to the downfall of the UK's motorcycle
industry, I know I owned many UK produced bikes. At least those industries
didn't manufacture aero engines.
Cheers,
Mike

[Denny]

More likely sloppy engineering standards
> which similarly and sadly led to the downfall of the UK's motorcycle
> industry,

A slight aside: that situation is the end point of all socialized
societies... Go along to get along, and all that...


denny

[nrp]

A fun science experiment is to put a small amount of water in the
bottom of a 1 gallon rectangular can. Boil it for a few minutes to
displace the air inside, remove it from the heat, and immediately
replace the cap and watch.

For more excitement, repeat with another can only this time cap it and
sprinkle cold water on the outside of the can too.

(Hint - don't plan on using the cans again.....!)

[Jay Honeck]

> * * * * My experience is as an aircraft mechanic.

Thanks for a great primer, Dan.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Roger (K8RI)]

On Wed, 19 Dec 2007 12:21:28 -0500, "Peter R." >
wrote:

>This time of year here in the Northeast US I always preheat my Bonanza's
>IO520 engine with a Tanis heater and an insulated cowling/prop cover as it
>sits in an unheated t-hangar. The result is that the oil temperature at
>startup is around 105 degrees F, even if the outside air temperature is as
>low as -15 degrees F.
>
>Monday night I arrived at my t-hangar to discover that at some point during
>the day the line person accidentally pulled out the plug connecting the Tanis
>heater to the small extension cord I use to extend the plug to the outside of
>the cowling cover, so the aircraft had not been preheating. Outside and
>inside temperatures were both a cold 25 degrees F.
>
>Given any other day, I would have plugged the aircraft back in and scrapped
>the flight but in this case I had an Angel Flight patient waiting in another
>city for my arrival and I was already late. Thus I made the painful decision
>to start up the aircraft and allow it to low idle until the oil heated
>thoroughly. A small consolation is that the engine had been recently filled
>with fresh Exxon Elite oil. To my relief the aircraft started right up.
>
>I know what I did has negative long term repercussions on my engine's health


Ahhhh...How do you "know" one cold start is going to have long term,
negative effects?

I normally preheat mine and when flying a lot the preheater was always
on with the cowl double wrapped. No condensation and worked great.

OTOH I have gone out on days that were really cold, not 25 degrees and
if I could get it to start I'd go flying without worrying about it.

I think you'll find that an engine that has set a long time and is
really cold takes a while to get oil to the cam. Every thing else gets
oiled just fine.

I'd not be overly concerned about a few cold starts as long as the
engine is given time enough to circulate warm oil.

In the Bo you'll know if it wasn't hot enough as the oil will congeal
in the oil cooler and the prop governor will let you know right away!
<:-))

>and I have already derived a tool to lock the two cords and prevent this
>accidental unplugging from happening again. However, this leads me to
>question the differences between aircraft engines and auto engines:
>
>Why is it that here in the Northeast US seemingly no one preheats their
>automobile engine before start-up in very cold temperatures? Is the long-term
>damage the same for both autos and aircraft engines? If so, why do you
>suppose auto owners don't typically do this? Is it because that most auto
>owners do not keep their cars very long?

Nearly all the cars we've had in recent years have gone between 100
and 200 thousand miles. None gave engine problems, none were
preheated, and all stayed outside, or in an unheated garage. The
engines stood up far better than the bodies did.

Roger (K8RI)

[Roger (K8RI)]

On Wed, 19 Dec 2007 17:35:50 +0000 (UTC),
(Paul Tomblin) wrote:

>In a previous article, "Peter R." > said:
>>Why is it that here in the Northeast US seemingly no one preheats their
>>automobile engine before start-up in very cold temperatures? Is the long-term
>>damage the same for both autos and aircraft engines? If so, why do you
>>suppose auto owners don't typically do this? Is it because that most auto
>>owners do not keep their cars very long?
>>
>
>
>Aircraft engines are air cooled, auto engines are liquid cooled.
>
>The following is what I was told when I was driving a Volkswagen Beetle,
>and the experts were saying that you needed to let the beast idle for at
>least 5 minutes in the winter:
>
>Liquid cooled engines stay in a very narrow temperature range while
>operating, so are built with very tight tolerances, but air cooled engines

Careful here. Don't confuse tight tolerances with tight clearances.
Aircraft engines have tighter tolerances than automobile engines.
Automobile engines have tighter clearances, but wider tolerances than
aircraft engines. If my car engine had the same fit as my IO-470N
it'd be considered worn out.

Roger (K8RI)
>have more slop because they get both hotter and colder than liquid cooled
>engines. Also, they are cooled primarily by the engine oil. Because of
>that, you need to preheat the engine enough that the oil is spread around
>and everything has warmed enough that the pistons are making good contact
>with the cylinder walls.

[David Lesher]

On Wed, 19 Dec 2007 12:21:28 -0500, "Peter R." >

>Why is it that here in the Northeast US seemingly no one preheats their
>automobile engine before start-up in very cold temperatures?

A) Automobiles have the advantage of 50+ years of research and innovation.
When did you last see a magneto ignition on a car? GA aircraft, however..

B) Ditto automobile oil. When I lived in the Twin Cities, Mobil 1 oil at
-25C was astonishing; you can spun over as if it was 35 degrees warmer.

C) Cars get used daily by most/many folks.

D) We're a nation of impatient, who GAF? people who'll sooner
buy a new car anyhow..


[ps: I did plug in my car when it got REALLY cold..]
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[Stealth Pilot[_2_]]

On Mon, 24 Dec 2007 04:47:22 +0000 (UTC), David Lesher
> wrote:

>
>On Wed, 19 Dec 2007 12:21:28 -0500, "Peter R." >
>
>>Why is it that here in the Northeast US seemingly no one preheats their
>>automobile engine before start-up in very cold temperatures?
>
>A) Automobiles have the advantage of 50+ years of research and innovation.
>When did you last see a magneto ignition on a car? GA aircraft, however..
>
aircraft have the same period of innovation but the developments have
been for a different aim. longevity. once the designs reached their
light weight optimum many aspects have stayed fixed.
an engine running for long periods at the same rpm has what sort of
need for vacuum advance? ...for instance.
it does have a need to be able to continue to run in spite of
electrical failure and a magneto and gravity feed do that for many
designs quite adequately. simplicity removes failure points due to
complexity. failures can kill you, simplicity keeps you alive.

aircraft have a higher risk of being struck by lightning. how much of
the high tech auto technology can survive a lightning strike?

I must admit that the dead hand of certification needs to be phased
out if there is any prospect of innovation again.
the current cosworth formula1 engines deliver 950hp at 20,000rpm from
an engine package smaller in capacity than an O-200.
I wouldnt mind a little bit more bleed through of the technology into
aviation.



>B) Ditto automobile oil. When I lived in the Twin Cities, Mobil 1 oil at
>-25C was astonishing; you can spun over as if it was 35 degrees warmer.
>
>C) Cars get used daily by most/many folks.
>
>D) We're a nation of impatient, who GAF? people who'll sooner
>buy a new car anyhow..
>
ahhh but that is the actual reason for the technical inovation behind
the automobile. it self perpetuates the sale of new cars.
functionally a T model ford would get you around as well as any modern
car. the expectations driven by technology wouldnt allow you to be
seen dead in one so you go out and buy a new high tech car capable of
200mph and a standing quarter in 5 seconds ...so that you can drive it
in peak hour stop start traffic all the while dreaming of a circuit at
brands hatch.
cunning buggers arent they :-)

[Mike Spera]

>>
>
> aircraft have the same period of innovation but the developments have
> been for a different aim. longevity. once the designs reached their
> light weight optimum many aspects have stayed fixed.
> an engine running for long periods at the same rpm has what sort of
> need for vacuum advance? ...for instance.
> it does have a need to be able to continue to run in spite of
> electrical failure and a magneto and gravity feed do that for many
> designs quite adequately. simplicity removes failure points due to
> complexity. failures can kill you, simplicity keeps you alive.
>
>

The thing that inhibits aircraft engine development appears to be simple
economics. With the HUGE certification and liability hurdles, there
simply are not enough potential sales to offset this economic mountain.
Auto engines can afford to fail in use because the consequences are
generally much less severe (you coast to a stop on the side of the
road). If the proposed auto innovation passes its early tests, the
market potential is generally large enough to make financial sense to go
ahead and put the thing in production.

The litigation blood suckers just about DARE anyone to attempt to
introduce any changes to the airplane market. The idiotic public puts up
with this nonsense and cheers on the suing family as they battle the
"big, bad corporation" who harmed their poor, defenseless family with
their "defective" product.

Airplane owners have a split personality as far as I can tell by reading
these forums. We cry "foul" when some idiot jury awards millions of
dollars in damages for an airplane mishap. But pilots are the first in
line to blame anyone in sight when it happens to them.

Curious lot.

Be Safe,
Mike

[David Lesher]

Stealth Pilot > writes:

>>A) Automobiles have the advantage of 50+ years of research and innovation.
>>When did you last see a magneto ignition on a car? GA aircraft, however..
>>
>aircraft have the same period of innovation but the developments have
>been for a different aim. longevity. once the designs reached their
>light weight optimum many aspects have stayed fixed.

I respectfully disagree. There are many things we've learned from which
GA aircraft could benefit: automotive, electronic, metallurgical, human
factors.

That they don't is likely due to a "coffin corner" of low volumes, and
high overhead {including but not limited to regulatory burden..}.

Do I think aircraft engines could benefit from closed loop fuel
systems ? Yep. Do I think such can survive
lightning? Yep. The Big Boys and the military aircraft do now; I recall
that thunderstorm research fighter at NASA-LaRC with the dozens of
thunderbolts stencils. Ditto TV/FM transmitters, who unlike the aircraft,
ARE a direct sink for the lightning. It takes some design but nothing
earthshaking.

But even small stuff, such as integral voltage regulators does not seem to come to pass.
[i]
>an engine running for long periods at the same rpm has what sort of
>need for vacuum advance? ...for instance.

Suppose a computerized fuel injection system offered oh, say 7% better
fuel consumption and 20% better TBO; would that be worth it? Look at the
MPG and engine life of a 1950's car and one from the last 5 years.
[i]
>>D) We're a nation of impatient, who GAF? people who'll sooner
>>buy a new car anyhow..
>>
>ahhh but that is the actual reason for the technical inovation behind
>the automobile. it self perpetuates the sale of new cars.

Perhaps, but the outcome is better cars. Until the Japanese invasion,
Detroit built crap, at multiple levels: engineering, manufacturing,
QC. The dope-slap they got took years to wake them up, but it and
regulatory burdens [1] have given the customer a vehicle that's far far
better than what [s]he could buy 40 years ago. I wish the GA industry
could say the same.


1: The MPG/smog ones forced them to give up on carbs. How could anyone
ever have improved on a Rochester Quadrajet for example -- why, it's a
marval of simplicity exceeded only by the 6.02E23 parts found in a
Model 28 Teletype, right?]
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[Capt. Geoffrey Thorpe]

"nrp" > wrote in message
...
<...>
> A lot of this moisture accumulation problem would go away if aircraft
> engines had a positive crankcase ventilation (PCV) system like car
> engines now do, but they don't for whatever reason. I suspect part of
> the reason car engines now last so much longer is due to the PCV
> system.

Talking to one of the "old guys" at work some years ago this came up - his
claim was that when PCV was first required, they were worried about
re-cycling all the "gunk" and damaging the engines - but testing (and
eventually field experience) showed that keeping the crankcase ventilated
resulted in a significant boost in engine durability. He referred to PCV as
one of the best things to come along...

Conventional auto style PCV won't work well on an aircraft engine due to the
lack of vacuum in the manifold to generate the air flow.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[Capt. Geoffrey Thorpe]

"Stealth Pilot" > wrote in message
...
<...>
> now to be serious...
> squeezing past the rings probably contributes a millionth of one
> poofteenth of a percent to the problem.

Stick your thumb on the crankcase breather and have someone open the
throttle - you will be surprised at the ammount of flow.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[Roger (K8RI)]

On Fri, 21 Dec 2007 08:18:12 -0800 (PST),
wrote:

>On Dec 21, 4:45 am, Stealth Pilot >
>wrote:
>
>> squeezing past the rings probably contributes a millionth of one
>> poofteenth of a percent to the problem.
>> when the crankcase cools there is moist external air sucked into the
>> cavity of the case through the crankcase breather. the moisture
>> condenses onto the cold internal surfaces of the engine.
>> can you please factor that into the alchemy above? it probably does
>> the damage occurring between the poofteenth of your scenario and the
>> 100%.
>
> Nope. We have taken rocker covers off engines immediately
>after a runup of a brand-new engine and found copious amounts of water

A runup doesn't do squat about removing moisture or acid. It takes a
10 to 15 minute flight of take off and cruise power. I've never seen
moisture after that, but I sure have after even a prolonged ground
run. Besides, unless it's tied down I can't even hit cruise power in
the runup without the tires skidding let alone full power. 24 X 24
and it'll start to acellerate which is kinda hard on the tires.

Roger (K8RI)
>in them. The blowby of any cold engine is significant. If we briefly
>run up an engine that has sat all night in a heated hangar and in our
>very dry winter climate, we will find water on the dipstick every
>time, with the engine at any point in its life. And the dipstick was
>dry beforehand.
> We operate on the western Canadian prairies where the air is
>drier that where I grew up in south-central BC, which is the northern
>tip of the Sonora Desert. We get little rain and snow here. Temps
>reach -40C, more typically -20C, no fog and clear skies most of the
>winter. It's REALLY dry, and any air sucked into these engines after
>shutdown doesn't have enough moisture to make a couple of tears.
>
> Dan

[[email protected]]

On Dec 25, 9:13 pm, "Roger (K8RI)" > wrote:

> > Nope. We have taken rocker covers off engines immediately
> >after a runup of a brand-new engine and found copious amounts of water
>
> A runup doesn't do squat about removing moisture or acid. It takes a
> 10 to 15 minute flight of take off and cruise power. I've never seen
> moisture after that, but I sure have after even a prolonged ground
> run. Besides, unless it's tied down I can't even hit cruise power in
> the runup without the tires skidding let alone full power. 24 X 24
> and it'll start to acellerate which is kinda hard on the tires.

My point was that there was lots of moisture in the case after a
runup, and that it would take considerable hard flying to get it out.
We had to redo jugs on our O-235 in one of the Citabrias at mid-
time. Those engines tend to run cool (I have no idea at all why
American Champion installs an oil cooler; its finned area is half
blocked off as installed and they incude a cover to block the rest off
in cooler weather) and the resulting condensation corrodes the
cylinder walls. The worst damage was on the front of the front
cylinders, the first area to cool after a flight, and that moisture
causes galvanic corrosion (aluminum piston against steel wall) and
pitting there. Then the rings wear it at a greater rate, a ridge forms
at the bottom of the ring travel, and that sharp ridge starts shaving
aluminum bits off the piston pin plugs. Aluminum slivers in the filter
are the first sign of the trouble.

Dan

[M[_1_]]

On Dec 25, 8:13 pm, "Roger (K8RI)" > wrote:

>

>
> A runup doesn't do squat about removing moisture or acid. It takes a
> 10 to 15 minute flight of take off and cruise power. I've never seen
> moisture after that, but I sure have after even a prolonged ground
> run.

10 to 15 minutes at cruise prower is a reasonable claim. To say it
takes at least one hours to heat up the engine enough to boil off
water is OWT (which I often hear about). If one thinks a 30 minute
cruise flight is too short to get rid of the water, does he reduce
power to land? The engine cools off as the plane descends and water
starts to accumulate in the oil according to this theory.

[M[_1_]]

On Dec 24, 2:42 am, Stealth Pilot >
> I must admit that the dead hand of certification needs to be phased
> out if there is any prospect of innovation again.
> the current cosworth formula1 engines deliver 950hp at 20,000rpm from
> an engine package smaller in capacity than an O-200.

I doubt such a formula 1 engine would have better power to weight
ratio if you add the weight of the reduction gear to get the prop tip
speed below supersonic. I also doubt it can match the BSFC of a
O-200.

People often claim the auto engines are so much better. I'd like to
see an automobile gasoline engine that has 1. better BSFC than an
IO-550 at its 75% rated power and 2. better power to weight ratio
including the weight of the reduction gear to drive a propeller.

http://www.prime-mover.org/Engines/GArticles/article2.html has a lot
of good info.

[[email protected]]

On Dec 30, 5:56*pm, M > wrote:
> On Dec 24, 2:42 am, Stealth Pilot >
>
> > I must admit that the dead hand of certification needs to be phased
> > out if there is any prospect of innovation again.
> > the current cosworth *formula1 engines deliver 950hp at 20,000rpm from
> > an engine package smaller in capacity than an O-200.
>
> I doubt such a formula 1 engine would have better power to weight
> ratio if you add the weight of the reduction gear to get the prop tip
> speed below supersonic. *I also doubt it can match the BSFC of a
> O-200.
>
> People often claim the auto engines are so much better. *I'd like to
> see an automobile gasoline engine that has 1. better BSFC than an
> IO-550 at its 75% rated power and 2. better power to weight ratio
> including the weight of the reduction gear to drive a propeller.
>
> http://www.prime-mover.org/Engines/GArticles/article2.htmlhas a lot
> of good info.

Deal,,,, Come on out to Jackson Hole Wy and I will demonstrate an auto
engine that will prove both of your questions wrong.

Ben Haas
www.haaspowerair.com

[M[_1_]]

On Dec 30, 5:27 pm, " > wrote:

>
> Deal,,,, Come on out to Jackson Hole Wy and I will demonstrate an auto
> engine that will prove both of your questions wrong.
>

No need for that. You should simply post your performance data right
here.

[[email protected]]

On Dec 30, 7:43*pm, M > wrote:
> On Dec 30, 5:27 pm, " > wrote:
>
>
>
> > Deal,,,, Come on out to Jackson Hole Wy and I will demonstrate an auto
> > engine that will prove both of your questions wrong.
>
> No need for that. *You should simply post your performance data right
> here.

No need for that, I sell only to the "experimental" plane market. Your
are stuck with the "certified" 60 year old technology. I will say I
don't think the IO-550 weighs 437 lbs complete with prop. Maybe 600+
lbs... :<(. Liquid cooled engines can and will get better BSCF numbers
then aircooled ones, it is a fact of life............

Happy New Year all.

Ben
www.haaspowerair.com

[[email protected]]

On Dec 31, 5:51 am, " > wrote:
> On Dec 30, 7:43 pm, M > wrote:
>
> > On Dec 30, 5:27 pm, " > wrote:
>
> > > Deal,,,, Come on out to Jackson Hole Wy and I will demonstrate an auto
> > > engine that will prove both of your questions wrong.
>
> > No need for that. You should simply post your performance data right
> > here.
>
> No need for that, I sell only to the "experimental" plane market. Your
> are stuck with the "certified" 60 year old technology. I will say I
> don't think the IO-550 weighs 437 lbs complete with prop. Maybe 600+
> lbs... :<(. Liquid cooled engines can and will get better BSCF numbers
> then aircooled ones, it is a fact of life............

Yup, because fuel isn't wasted trying to keep the engine cool
at high power settings like at takeoff and climb. But it improves too
with the variable ignition timing found on auto engines, and
frequently they have higher compression, giving more bang per buck
without worrying about the detonation common in aircooled big-cylinder
engines. And they have sensible, efficient intake systems instead of
tight elbows or pipes clamped together with rubber tubes.

Dan

[M[_1_]]

On Dec 31 2007, 4:51 am, " > wrote:
> On Dec 30, 7:43 pm, M > wrote:
>
> > On Dec 30, 5:27 pm, " > wrote:
>
> > > Deal,,,, Come on out to Jackson Hole Wy and I will demonstrate an auto
> > > engine that will prove both of your questions wrong.
>
> > No need for that. You should simply post your performance data right
> > here.
>
> No need for that, I sell only to the "experimental" plane market. Y


Interesting. I have no doubt that you make nice engines, but being in
the experimental market still has objective performance data, like
BSFC at cruise power, installed weight, etc. I haven't yet seen your
numbers. To say your engine is really light and fuel efficient is
like saying my plane is really, really fast. What does it mean?

> Happy New Year all.
>

Same here. Happy new year all.

[[email protected]]

On Jan 1, 4:55*pm, M > wrote:
> On Dec 31 2007, 4:51 am, " > wrote:
>
> > On Dec 30, 7:43 pm, M > wrote:
>
> > > On Dec 30, 5:27 pm, " > wrote:
>
> > > > Deal,,,, Come on out to Jackson Hole Wy and I will demonstrate an auto
> > > > engine that will prove both of your questions wrong.
>
> > > No need for that. *You should simply post your performance data right
> > > here.
>
> > No need for that, I sell only to the "experimental" plane market. Y
>
> Interesting. *I have no doubt that you make nice engines, but being in
> the experimental market still has objective performance data, like
> BSFC at cruise power, installed weight, etc. *I haven't yet seen your
> numbers. *To say your engine is really light and fuel efficient is
> like saying my plane is really, really fast. *What does it mean?
>
> > Happy New Year all.
>
> Same here. *Happy new year all.

I have already released the installed weight, 437 lbs,,, COMPLETE,
with redrive and prop. I could do the bait and switch like Lycoming
and Continental does. Their weight is for bare and stripped engines.
Like, 0-360 is 287 lbs, oh do ya need a fuel injection system???
that weighs more, oh, da ya need a starter??? that weighs more. Oh do
ya need an ignition system??? . And on and on,,,, I helped remove a
complete 0-360 with a constant speed prop from a plane a few years
back. When I say complete I mean everything it took to get that plane
into the air, exhaust system, fuel system, baffles, starter.
alternator, yada,yada,yada... The thing weighed 456 lbs, and thats for
180 hp.... I can do more then twice the power for 19 lbs lighter... I
am still in testing and my project could kill me on the next flight
but I am pretty sure I have it debugged pretty well. In fact I just
rolled it back into the hangar about 20 minutes ago after a nice long
flight around the Jackson Hole/ Yellowstone area. The terrain is very
hostile and probably not the best place to R&D a one of a kind engine
but I have alot of confidence in it . Did I mention the cabin heat is
Wonderful using the coolant through a heater core, No CO,,,, and it is
-8f as I type this. Cabin stays in the 70's.

Tailwinds guys....

Ben

[[email protected]]

On Dec 30 2007, 5:42 pm, M > wrote:
> On Dec 25, 8:13 pm, "Roger (K8RI)" > wrote:
>
>
>
> > A runup doesn't do squat about removing moisture or acid. It takes a
> > 10 to 15 minute flight of take off and cruise power. I've never seen
> > moisture after that, but I sure have after even a prolonged ground
> > run.
>
> 10 to 15 minutes at cruise prower is a reasonable claim. To say it
> takes at least one hours to heat up the engine enough to boil off
> water is OWT (which I often hear about). If one thinks a 30 minute
> cruise flight is too short to get rid of the water, does he reduce
> power to land? The engine cools off as the plane descends and water
> starts to accumulate in the oil according to this theory.

10 to 15 minutes in air that is -15 or -20°C won't warm
the oil enough to get the water out. If the weather is cold enough,
the water may not leave at all. We have that problem here on the
Canadian prairies. I wish we had liquid cooling.
Closing the throttle on a warmed-up engine isn't the
same as a cold engine idling. The pistons and rings are much warmer
and the gaps have closed up some. And a windmilling engine generates
much less cylinder pressure at idle than it does on the ground, so
blowby is less.

Dan