Diesel for Diamond DA40?

On 2007-05-22, Greg Copeland wrote:
Okay, seems I stand corrected. Just FYI, I looked this morning and
diesel fuel is 18% heavier. I had also assumed that they had placed a
FADEC setup on the Lyc, thusly greatly improving its effeciency too.
Guess not. Many people don't realize that much of the effeciency
associated with these engines comes from FADEC rather than diesel in
of it self.

I'm not sure that's really true either - in the automotive world
(certainly on this side of the planet) where diesel cars are common, an
equivalent performance diesel powered car has significantly lower fuel
consumption than a petrol (gasoline) powered car. Both are completely
FADEC (most modern cars don't even have a physical linkage from the gas
pedal to the engine any more). Diesel engines are considerably more
thermodynamically efficient.

Even the old mechanical injection turbodiesels will get better fuel
economy than a brand new gasoline car of the same power output. It's
probably why the Prius just isn't selling over here - why spend that
much money on a hybrid, when you can get a diesel car with the
equivalent fuel economy for less money?

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

Dylan,

(most modern cars don't even have a physical linkage from the gas
pedal to the engine any more)


The Thielert doesn't, either.

--
Thomas Borchert (EDDH)

"Dylan Smith" wrote in message
...
On 2007-05-22, Greg Copeland wrote:
Okay, seems I stand corrected. Just FYI, I looked this morning and
diesel fuel is 18% heavier. I had also assumed that they had placed a
FADEC setup on the Lyc, thusly greatly improving its effeciency too.
Guess not. Many people don't realize that much of the effeciency
associated with these engines comes from FADEC rather than diesel in
of it self.

I'm not sure that's really true either - in the automotive world
(certainly on this side of the planet) where diesel cars are common, an
equivalent performance diesel powered car has significantly lower fuel
consumption than a petrol (gasoline) powered car. Both are completely
FADEC (most modern cars don't even have a physical linkage from the gas
pedal to the engine any more). Diesel engines are considerably more
thermodynamically efficient.

Even the old mechanical injection turbodiesels will get better fuel
economy than a brand new gasoline car of the same power output. It's
probably why the Prius just isn't selling over here - why spend that
much money on a hybrid, when you can get a diesel car with the
equivalent fuel economy for less money?

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

All of that appears true, and I suspect that the biggest reason that diesel
cars have not really become popular here (in the USA) is that all advertised
fuel economy figures are required to be those from EPA testing. I only
recently read that those numbers are only calculated from exhaust emissions,
that fuel flow is (apparently) not metered, and that gasolene engines do not
actually run on (retail) gasolene for the test. The published/adverttised
data would suggest that gasolene hybrids (such as Prius) will never
completely pay back their price premium without governmental tax
incentives--and that the diesels will pay back their price premium in about
100,000 miles.

However, many small trucks are popluar here with both gasolene and diesel
power and anecdotal information from small truck owners strongly suggests
that the diesel advantage is more that twice the difference which is
officially documented and advertised; and the Thielert numbers suggest that
it is the diesel truck (and automobile) owners who really have the numbers
right. I have not yet made the switch, but plan to do so in the forseeable
future.

Peter

"Greg Copeland" wrote in message Okay, seems I
stand corrected. Just FYI, I looked this morning and
diesel fuel is 18% heavier. I had also assumed that they had placed a
FADEC setup on the Lyc, thusly greatly improving its effeciency too.
Guess not. Many people don't realize that much of the effeciency
associated with these engines comes from FADEC rather than diesel in
of it self.


FADEC won't make an engine run more efficiently. It will make it easier to
manage.

"Curator" N185KG

karl gruber wrote:
"Greg Copeland" wrote in message Okay, seems
I stand corrected. Just FYI, I looked this morning and
diesel fuel is 18% heavier. I had also assumed that they had placed
a FADEC setup on the Lyc, thusly greatly improving its effeciency
too. Guess not. Many people don't realize that much of the
effeciency associated with these engines comes from FADEC rather
than diesel in of it self.


FADEC won't make an engine run more efficiently. It will make it
easier to manage.

and thus it will make it run more efficiently than a improperly managed
manually controlled engine.

regards,
Friedrich

"karl gruber" wrote

FADEC won't make an engine run more efficiently. It will make it easier to
manage.

In a way that is true, but at the same time it is as false as can be.

A properly leaned engine at cruise, with well matched injectors, will have
all of the cylinders humming happily along at the most efficient setting,
and lowest fuel flow. FADEC can not improve on that much, if any.

But, and it is a big but, think of the settings we run on takeoff, and
landing (in case you have to do a go-around) and of the time you are at
idle, or low power on the ground. You are running much richer than need be,
and not as lean as FADEC would have things set. On the average, us setting
the mixture is wasting fuel, and is inefficient as compared to FADEC. FADEC
will reset the mixture many times per second; as often as is needed. That
is something we can never begin to think about doing.
--
Jim in NC

Greg Copeland wrote:



Hmm. Not sure why you put it that way. The IO360 is well know for
being rock solid. Diesel aircraft engines typically cost you useful
load because of their weight and the fuel is heavier to boot. A
double whammy on useful load isn't exactly exciting. IIRC, the
diesels that Diamond have certified don't have a 2000hr TBO either.
Didn't they just get it increased from 1200hrs to 1500hr or something
like that? On top of all that, the energy density for 100LL is some
20% higher (IIRC; or was it 40%) which means fuel consumption is 20%
higher for the same HP rating.


When I had my 182 there was all kinds of talk about the diesel that was
going into the plane. The diesels were lighter, not heavier. The O-470
burns about 13 GPH at 75% where the diesel would burn about 9 GPH at the
same power setting. The range of the plane went up significantly. I do
not recall any talk about the loss of useful load due to the difference
in weight of the fuel. If the diesel were 1 pound heavier per gallon
you'd lose 56-96 pounds depending on your model. An irrelevant loss as
you could just leave out that weight of fuel and still be far ahead of
the game weight wise. The real downside was the cost to convert. They
wanted $80K which is a price nobody will pay because the break even
point is still way too far into the future. The TBO, which was really a
TBR and really big bucks, was supposed to start at 2000 hours and make
its way to 3000 and eventually 4000 hours.

Newps,

The real downside was the cost to convert. They
wanted $80K which is a price nobody will pay because the break even
point is still way too far into the future. The TBO, which was really a
TBR and really big bucks, was supposed to start at 2000 hours and make
its way to 3000 and eventually 4000 hours.


That was the sma diesel. They haven't really taken off (yet).

--
Thomas Borchert (EDDH)

On 2007-05-22, Newps wrote:

The real downside was the cost to convert. They wanted $80K which
is a price nobody will pay because the break even point is still way
too far into the future.

So the question is: where is the break even point? If you account for
the reduced maintenance costs, and you make your own biodiesel at
~$1/gal., would you say the break even point is acceptable?

--
PM instructions: do a C4esar Ciph3r on my address; retain punctuation.

Justin Gombos wrote:

On 2007-05-22, Newps wrote:

The real downside was the cost to convert. They wanted $80K which
is a price nobody will pay because the break even point is still way
too far into the future.


So the question is: where is the break even point? If you account for
the reduced maintenance costs,



Nobody knows that yet. Too many different technologies have come and
gone promising lower costs. When the diesel has proven itself to cost
less in the field I will believe it. Until then it's pure speculation.




and you make your own biodiesel at
~$1/gal., would you say the break even point is acceptable?



I don't know. First off putting $80K into a $50K airplane won't happen
for that reason alone. Second the guy who has $80K to put into a 182
isn't the kind of guy who homebrews his own biodiesel. Simple fact of
the matter is $80K is a deal breaker. Get it down to $40K, about the
same as putting a big engine in a 182, and then you've got something.
But at $80K you won't have any market penetration at all. And really at
$40K look how many 300 HP 550's are in 182's now. I wouldn't call it
rare but it's still a fairly small percentage.