Diesel for Diamond DA40?

Anybody know whether the Diamond DA40 is available with diesel power
in the U.S.? I checked the website and the only engine is the ancient
Lycoming IO360.

On May 21, 8:54 pm, Paul kgyy wrote:
Anybody know whether the Diamond DA40 is available with diesel power
in the U.S.? I checked the website and the only engine is the ancient
Lycoming IO360.

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.

Overall, aside from diesel fuel prices, I don't see a big advantage
especially once you multiply the diesel fuel price by %120 to compare
what it would cost you to travel the same distance via 100LL. Once
you add in the engine reserve for a 1500hr (IIRC) engine versus a
2000hr engine and the extra fuel required, one has to wonder if the
diesel price per gallon is worth it in the big picture.

Are you sure you still want diesel power?


Greg

Greg Copeland schrieb:
On May 21, 8:54 pm, Paul kgyy wrote:
Anybody know whether the Diamond DA40 is available with diesel power
in the U.S.? I checked the website and the only engine is the ancient
Lycoming IO360.

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.

Overall, aside from diesel fuel prices, I don't see a big advantage
especially once you multiply the diesel fuel price by %120 to compare
what it would cost you to travel the same distance via 100LL. Once
you add in the engine reserve for a 1500hr (IIRC) engine versus a
2000hr engine and the extra fuel required, one has to wonder if the
diesel price per gallon is worth it in the big picture.

Are you sure you still want diesel power?


Greg

Ups, I guess you have never seen a modern diesel. You are comparing a
1940 avgas dino vs. a 2000 diesel. For comparison take a look at

http://de.wikipedia.org/wiki/Diamond_DA40 (Soory, it´s german)

The diesel has 30 kg more weight and thus 30 kg less pay load. But it
takes only about 15 liters per hour vs. 27 liter per hour for the avgas
dino. This means for a 3 hour trip or more you have more usable payload
in the diesel powererd DA40.


Michael

Greg Copeland wrote:
On May 21, 8:54 pm, Paul kgyy wrote:
Anybody know whether the Diamond DA40 is available with diesel power
in the U.S.? I checked the website and the only engine is the ancient
Lycoming IO360.

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.

I'm don't know how the weight of the diesel for the Diamond compares,
but you are wrong on the the fuel weight issue. Well it is heavier per
gallon, but you can go much further on a lbs of diesel than you can on a
lbs of gas. If you fill the tanks to the top you will have less useful
load but if put in the amount of diesel that it would take to go the
same distance you could on gas, there would be fewer lbs of fuel in the
tank. Which also means if you need the extra range, going diesel is
like adding larger tanks. You are right that there is more energy per
lbs of gas, however, diesel engines more than make up for that because
they are more efficient than gas engines.

The way I see it the only disadvantage to diesel, and it is a huge
disadvantage, is the lack of proven engines to pick from.




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On 22 May, 05:37, Greg Copeland wrote:
On May 21, 8:54 pm, Paul kgyy wrote:

Anybody know whether the Diamond DA40 is available with diesel power
in the U.S.? I checked the website and the only engine is the ancient
Lycoming IO360.

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,

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.

It seems that you do not recall correctly.
Quite a lot of people disagree with these numbers.
Chevron for example seem to think that the
difference in enengy density between kerosene and
aviation gasoline is rather smaller than either of
your figures. The inherent efficiency of the
diesel at part throttle does the rest.

http://hypertextbook.com/facts/2003/EvelynGofman.shtml

Everyone else that I have read on the subject
(other than yourself) seems to reach the
opposite conclusion regarding range/payload.

"Greg Copeland" wrote

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.

I think you have that backwards. Diesel fuel has a higher energy density
than 100LL. You burn less fuel per HP produced.
--
Jim in NC

Morgans wrote:
"Greg Copeland" wrote

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.

I think you have that backwards. Diesel fuel has a higher energy
density than 100LL. You burn less fuel per HP produced.

actually the energy density by weight is about the same. However Diesel is
about 0.85 kg/litre, while Gasoline is 0.725 kg/l. So the energy content per
volume per litre/gallon is higher for diesel.

However the important point here is the efficiency of the engine, Diesels
do about 15-30% better. So from the same weight of fuel a Diesel will get up
to 30% more energy to the prop. While most diesel engines are indeed a
slight bit heavier than gasoline engines of similar power output, the weight
of a diesel engine plus fuel for any decent range is less than with
gasoline, hence useful payload is better.

If gross weight is not an issue but fuel tank capacity, a diesel will
extend your range through better efficiency AND the higher energy content
per volume.

And of course there is the price issue, in Europe Diesel (or Jetfuel) is
significantly cheaper than Avgas. Some Thielert operators claim a reduction
in overall fuel cost, fuel price times fuel consumption, of up to 2/3 vs.
Avgas.

If I was shopping for a new engine (or a new plane with new engine) I would
go for a diesel.

regards,
Friedrich

Greg,

Hmm. Not sure why you put it that way. The IO360 is well know for
being rock solid.

But it's still ancient. ;-)

Diesel aircraft engines typically cost you useful
load because of their weight and the fuel is heavier to boot.

The fuel contains more energy, too, so you need less. In all, we're talking about a few pounds. In
the case of the DA-40, look at the specs.

IIRC, the
diesels that Diamond have certified don't have a 2000hr TBO either.

Nope, they are scheduled for a 2400 hours TBR (replacement). Granted, at the moment they are
certified to something in the 1000s, but Thielert/Diamond will prorate the replacement cost as if it
were 2400 hours. Going in, you know exactly what that engine is going to cost you. No extras for
surprise to overhauls or anything like that. And 2400 hours seems REALLY decent to me.

On top of all that, the energy density for 100LL is some
20% higher

It's the other way around. Diesel has a higher energy density. It's much less than 20 percent,
though.

Overall, aside from diesel fuel prices, I don't see a big advantage
especially once you multiply the diesel fuel price by %120 to compare
what it would cost you to travel the same distance via 100LL.

Again, you got that wrong. Also, the fuel consumption of that modern, electronically controlled
engine is WAY lower than with the ancient Lyc.

Once
you add in the engine reserve for a 1500hr (IIRC) engine versus a
2000hr engine and the extra fuel required,

As described above, that's wrong.

Are you sure you still want diesel power?

Are YOU still sure you want a Lycosaurus? ;-)

--
Thomas Borchert (EDDH)

On 2007-05-22, 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.

The Thielert diesel burns about half the fuel of an IO360 with very
little performance loss. I think that's exciting. So you get MORE useful
load because you need vastly less fuel.

20% higher (IIRC; or was it 40%) which means fuel consumption is 20%
higher for the same HP rating.

I'm really curious - where did you get these numbers from? The diesel
burns about 50% of the fuel of an O-320, let alone an IO-360.

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

On May 22, 3:50 am, Dylan Smith wrote:
On 2007-05-22, 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.

The Thielert diesel burns about half the fuel of an IO360 with very
little performance loss. I think that's exciting. So you get MORE useful
load because you need vastly less fuel.

20% higher (IIRC; or was it 40%) which means fuel consumption is 20%
higher for the same HP rating.

I'm really curious - where did you get these numbers from? The diesel
burns about 50% of the fuel of an O-320, let alone an IO-360.

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

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.

Greg