Cold Starts

Well, there's preheats and there's preheats...
A quick preheat with a red dragon makes you feel warm all over (so does
urinary incontinence while wearing a dark wool suit) but doesn't do much of
anything except make the exterior sheet metal, fins, etc., temporarily
warm... The oil is still at ambient in the pan, and definitely ambient upon
entering the oil pump... And that great steel slab of rotating oil passages
they call a crank is still at -4 degrees, or whatever, to the oil trying to
flow through it - chilling the 'supposedly' warm oil quite nicely and
instantly...
notice that the crank has two or more 'ambient temperature equalizing heat
sinks' firmly attached......
Of course, you feel all warm and secure - if not actually doing a lot for
the engine - so I suppose that's worth something...

Same deal for an oil pan heater... You have a puddle of relatively warm oil
(often with a chilled center if it is the typical preheat) that will assume
crank/prop and case temperatures immediately upon flowing into the
passages...

If you read the aggregate wisdom of the alaskan/arctic flyers, you will see
that a preheat includes a solid hour - and usually more - of a red dragon
with the pedal to the metal, cowl blankets and prop booties, pouring the
heated oil (from a stove) into the engine and immediately starting...

Now the Reif, et. al., systems of cylinder clamps and pan pads can be
helpful IF they are on for a number of hours with an good, metallized,
insulated, blanket tightly wrapped, booties on the prop and hub, and no air
blowing up the exhaust, to allow the heat to soak all the way to the center
of the crank... Less effort than that and you are kidding yourself...


denny

"Dale" wrote in message "Dennis O'Connor"
wrote:

I started my engines this morning at -4 F... No preheat never do
That's the way this airplane has been treated ever since
semisynthetic, multiviscosity, oils came out.... Engines go to TBO
routinely...

Wow. To each his own. I would never start at those temps without
preheat, and I also used 15W50. I've also tried to pour it when it's
cold. G If it works for you, great.

"Dennis O'Connor" wrote in message
...
Well, there's preheats and there's preheats...
A quick preheat with a red dragon makes you feel warm all over (so does
urinary incontinence while wearing a dark wool suit) but doesn't do much
of
anything except make the exterior sheet metal, fins, etc., temporarily
warm... The oil is still at ambient in the pan, and definitely ambient
upon
entering the oil pump... And that great steel slab of rotating oil
passages
they call a crank is still at -4 degrees, or whatever, to the oil trying
to
flow through it - chilling the 'supposedly' warm oil quite nicely and
instantly...
notice that the crank has two or more 'ambient temperature equalizing
heat
sinks' firmly attached......
Of course, you feel all warm and secure - if not actually doing a lot for
the engine - so I suppose that's worth something...

Same deal for an oil pan heater... You have a puddle of relatively warm
oil
(often with a chilled center if it is the typical preheat) that will
assume
crank/prop and case temperatures immediately upon flowing into the
passages...

If you read the aggregate wisdom of the alaskan/arctic flyers, you will
see
that a preheat includes a solid hour - and usually more - of a red dragon
with the pedal to the metal, cowl blankets and prop booties, pouring the
heated oil (from a stove) into the engine and immediately starting...

Now the Reif, et. al., systems of cylinder clamps and pan pads can be
helpful IF they are on for a number of hours with an good, metallized,
insulated, blanket tightly wrapped, booties on the prop and hub, and no
air
blowing up the exhaust, to allow the heat to soak all the way to the
center
of the crank... Less effort than that and you are kidding yourself...


denny

How come the engine in my car with 190,000 miles is running fine with no
signs of undue wear with nary a single preheat. It is often started at
temps well below 0 F. Aluminium block, steel crank, steel cylinder liners
and aluminium pistons same as the ole Continental.



"Dale" wrote in message "Dennis O'Connor"
wrote:

I started my engines this morning at -4 F... No preheat never do
That's the way this airplane has been treated ever since
semisynthetic, multiviscosity, oils came out.... Engines go to TBO
routinely...

Wow. To each his own. I would never start at those temps without
preheat, and I also used 15W50. I've also tried to pour it when it's
cold. G If it works for you, great.

In article , "Dennis O'Connor"
wrote:

Well, there's preheats and there's preheats...
A quick preheat with a red dragon makes you feel warm all over (so does
urinary incontinence while wearing a dark wool suit) but doesn't do much
of
anything except make the exterior sheet metal, fins, etc., temporarily
warm... The oil is still at ambient in the pan, and definitely ambient
upon
entering the oil pump... And that great steel slab of rotating oil
passages
they call a crank is still at -4 degrees, or whatever, to the oil trying
to
flow through it - chilling the 'supposedly' warm oil quite nicely and
instantly...
notice that the crank has two or more 'ambient temperature equalizing
heat
sinks' firmly attached......
Of course, you feel all warm and secure - if not actually doing a lot for
the engine - so I suppose that's worth something...

well, I've done the no-preheat thing on a 30 degree day and the prop
didn't spin all that fast (barely started). With a preheat on a
20 degree day the prop spins a lot faster. Preheating does something
for my engine.

--
Bob Noel

On Sun, 15 Feb 2004 13:18:35 GMT, "Viperdoc"
wrote:

Is it worth lugging long extension cords to plug in the Tanis heaters for my
Baron if it's going to sit outside at 12 degrees for two to three hours
after a flight?

I have cowl plugs which may help a little, but is it really a problem? The
oil will be well circulated, and the battery is in good shape to crank the
engines.

On my Lyc IO360, I would put on a cowl cover if I'm going to be parked in
sub 20°F weather for more than an hour. If I did not, and if the engine
were not warm to the touch when I returned, I would preheat.


Also, the POH says to keep the cowl flaps open during taxi and take off, but
when it's so cold outside does this still make sense? As long as the CHTs
remain within a reasonable range what difference should it make?

CHT's only measure temperature in one area of the cylinder. When the
engine is running and the airplane is flying, if the baffling is intact
this gives a representative number for the engine.

However, when not flying, air flow over the engine will be different, so
some areas may overheat if the POH directions are modified depending on OAT
(unless it's been tested).


Thanks from Wisconsin, where its 2 degrees and clear.


And we're up to 6° now, on the coast.


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

Just got back from the flight with the Baron, with the OAT on the ground
being around 15 degrees. Playing with the mixture enroute I could never get
the CHT's over around 325 on any cylinder. (I left the winter baffles off to
see if there were any differences in CHT and performance).

The oil temp did not go over 150 on either engine, which is a little low.

After sitting outside at 15 degrees with a 5-10k wind, the oil temps were
still at 50 degrees after three hours with the cowl plugs in place. Although
I have Tanis heaters, there were no outlets anywhere near the tiedown, so
plugging it in was out of the question. Both started within a few blades, as
normal.

Anyway, I taxied with the cowl flaps closed to try to warm the oil, but took
off with them open. CHT's never went above 325 on any cylinder. Probably
could have left them closed.

Can't wait for warm weather, then will probably post about dodging
thunderstorms.

The heads can become overheated around the exhaust ports whilst the crank is
still slinging gobs of frozen condensate about... Keep em open...
denny
"Viperdoc" wrote in message
...
Is it worth lugging long extension cords to plug in the Tanis heaters for
my
Baron if it's going to sit outside at 12 degrees for two to three hours
after a flight?

I have cowl plugs which may help a little, but is it really a problem? The
oil will be well circulated, and the battery is in good shape to crank the
engines.

Also, the POH says to keep the cowl flaps open during taxi and take off,
but
when it's so cold outside does this still make sense? As long as the CHTs
remain within a reasonable range what difference should it make?

Thanks from Wisconsin, where its 2 degrees and clear.

Those little Honda 1000's at 29# would be the cats pajamas.

If you could keep it from growing legs....

Mike Z

"Viperdoc" wrote in message ...
Is it worth lugging long extension cords to plug in the Tanis heaters for my
Baron if it's going to sit outside at 12 degrees for two to three hours
after a flight?

I have cowl plugs which may help a little, but is it really a problem? The
oil will be well circulated, and the battery is in good shape to crank the
engines.

Also, the POH says to keep the cowl flaps open during taxi and take off, but
when it's so cold outside does this still make sense? As long as the CHTs
remain within a reasonable range what difference should it make?

Thanks from Wisconsin, where its 2 degrees and clear.

Well,,,desperate men do desperate things.

Stay at a motel near the airport and go out and start your plane and
run it for 1/2 hour every 4 hours. Bring the walkman.

Wasn't that the basis for a song about a beautiful woman and a desperate
man?
denny

"Doug" wrote in message
om...
Well,,,desperate men do desperate things.

No No!
Ground running is NOT good for an engine. Uneven cooling, you know!

Take it up for a 1 hour FLIGHT each four hours!

That's the PROPER way to keep it warm.

Rich

Doug wrote:

Well,,,desperate men do desperate things.

Stay at a motel near the airport and go out and start your plane and
run it for 1/2 hour every 4 hours. Bring the walkman.