Preheating engines: Airplane engines versus auto engines

"Matt W. Barrow" wrote
news


"gpaleo" wrote in message
news:1198154485.901022@athprx03...
"Matt Whiting" wrote
news
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.

gpaleo wrote:
"Matt Whiting" wrote
news

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

"gpaleo" wrote in message
news:1198177392.30618@athprx03...
"Matt W. Barrow" wrote
news


"gpaleo" wrote in message
news:1198154485.901022@athprx03...
"Matt Whiting" wrote
news 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 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

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

Ï "Matt W. Barrow" Ýãñáøå óôï ìÞíõìá
...


"gpaleo" wrote in message
news:1198177392.30618@athprx03...
"Matt W. Barrow" wrote
news


"gpaleo" wrote in message
news:1198154485.901022@athprx03...
"Matt Whiting" wrote
news
.................................................. ...............................
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).

"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.

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
news

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??

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)

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