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)

Paul kgyy schrieb:
Anybody know whether the Diamond DA40 is available with diesel power
in the U.S.?

Not yet. Until now, Thielert has sold their engines only in Europe. They
want to have them near the factory until enough engines have reached
their life lmit to really judge their reliability. Although well
engineered, it's a new engine and they don't want to take the risk of
getting a bad reputantion which would stick. Of course they will
eventually sell to the USA, as soon as they feel comfortable and have
installed a dealer base.

"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

Stefan,

Until now, Thielert has sold their engines only in Europe.


Actually, they are selling the DA-42 with Thielert engines in the US
and have been for some months now.

--
Thomas Borchert (EDDH)

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)

I checked with Diamond directly, and the diesel version is available
only in Europe.

They (and apparently also Cirrus) are "evaluating their options".

"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

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