Three Gallons Per Hour

[Phil J]

Aero News has a story today about Indus Aviation flying a diesel
Thorpedo burning only three gallons of Jet-A per hour. It uses a
WAM-120 turbocharged three-cylinder diesel engine generating 120
horsepower. One drawback of the engine - the installed weight is 279
pounds. But on the plus side it uses a mechanical control unit rather
than electronic. The "projected" TBO is 3000 hours.

Phil

[Bertie the Bunyip[_24_]]

Phil J > wrote in news:748b4d47-77dc-49a8-8252-
:

> Aero News has a story today about Indus Aviation flying a diesel
> Thorpedo burning only three gallons of Jet-A per hour. It uses a
> WAM-120 turbocharged three-cylinder diesel engine generating 120
> horsepower. One drawback of the engine - the installed weight is 279
> pounds. But on the plus side it uses a mechanical control unit rather
> than electronic. The "projected" TBO is 3000 hours.
>
> Phil
>

Last I heard of that one it was more like 4-5 GPH. That might be an
Imperial measurement.


Bertie

[Denny]

Hmmm, My BS meter is twitching...This is a BSFC of ~0.142

The very best diesel BSFC is the huge japanese engines used in
container ships at roughly 0.30...

denny

[M[_1_]]

On Apr 13, 12:29 pm, Denny > wrote:
> Hmmm, My BS meter is twitching...This is a BSFC of ~0.142
>
> The very best diesel BSFC is the huge japanese engines used in
> container ships at roughly 0.30...
>
> denny


How did you get SFC of 0.142?

That 3gph might be based on say 50% power (60HP is plenty for cruise
flight on a LSA on a local sight-seeing trip). That'll make SFC: 3 *
6.8 / 60 = 0.34 lb-hr/HP. That's quite doable on a diesel.

[Phil J]

On Apr 13, 2:10*pm, Bertie the Bunyip > wrote:
> Phil J > wrote in news:748b4d47-77dc-49a8-8252-
> :
>
> > Aero News has a story today about Indus Aviation flying a diesel
> > Thorpedo burning only three gallons of Jet-A per hour. *It uses a
> > WAM-120 turbocharged three-cylinder diesel engine generating 120
> > horsepower. *One drawback of the engine - the installed weight is 279
> > pounds. *But on the plus side it uses a mechanical control unit rather
> > than electronic. *The "projected" TBO is 3000 hours.
>
> > Phil
>
> Last I heard of that one it was more like 4-5 GPH. That might be an
> Imperial measurement.
>
> Bertie

Indus claimed three gallons per hour for a flight from Dallas, Texas
to Lakeland, Florida. I would guess that they throttled back to the
leanest possible cruise. In an EAA news article they are claiming 3.5
to 4 gallons per hour ( http://www.eaa.org/news/2008/2008-04-12_indus.asp
).

Phil

[M[_1_]]

>
> The very best diesel BSFC is the huge japanese engines used in
> container ships at roughly 0.30...
>

BTW, SFC 0.30 is achievable on mid-size ship diesel. The largest ship
diesel engines can do 0.28 lb-hr/HP or less:

http://people.bath.ac.uk/ccsshb/12cyl/

[M[_1_]]

On Apr 13, 4:13 pm, Phil J > wrote:

>
> Indus claimed three gallons per hour for a flight from Dallas, Texas
> to Lakeland, Florida. I would guess that they throttled back to the
> leanest possible cruise.

No doubt that 3gph figure must be an economic cruise power setting,
likely below 50% power.

BTW on a diesel, the combustion is well lean of stoichiometric even at
the max rated power. The air intake is not throttle and the
"throttle" control in a diesel engine is the fuel flow control.
There's no such thing as lean of peak or best power mixture :-) You
reduce the fuel flow and the engine produces less power. You increase
the fuel flow and the engine produces more power - until you reach the
soot limit or other thermo/mechanical limit for the particular engine
and that's the max rated power.

[Bertie the Bunyip[_24_]]

Denny > wrote in news:b71e5ad0-64ee-483e-8102-
:

> Hmmm, My BS meter is twitching...This is a BSFC of ~0.142
>
> The very best diesel BSFC is the huge japanese engines used in
> container ships at roughly 0.30...
>
> denny
>

Well, here they're saying somethign quite different

http://www.wilksch.com/wam-120.html

The 3 GPH might not have been at econ cruise, but it was probably at max
endurance, i.e., just enough to keep them aloft.



Bertie

[Peter Dohm]

"Bertie the Bunyip" > wrote in message
...
> Denny > wrote in news:b71e5ad0-64ee-483e-8102-
> :
>
>> Hmmm, My BS meter is twitching...This is a BSFC of ~0.142
>>
>> The very best diesel BSFC is the huge japanese engines used in
>> container ships at roughly 0.30...
>>
>> denny
>>
>
> Well, here they're saying somethign quite different
>
> http://www.wilksch.com/wam-120.html
>
> The 3 GPH might not have been at econ cruise, but it was probably at max
> endurance, i.e., just enough to keep them aloft.
>
>
>
> Bertie

And the Wilksch Airmotive numbers for specific fuel consumption are
resoundingly unimpressive for a diesel. It sure is light though!

Peter

[Phil J]

On Apr 13, 6:21*pm, M > wrote:
> On Apr 13, 4:13 pm, Phil J > wrote:
>
>
>
> > Indus claimed three gallons per hour for a flight from Dallas, Texas
> > to Lakeland, Florida. *I would guess that they throttled back to the
> > leanest possible cruise.
>
> No doubt that 3gph figure must be an economic cruise power setting,
> likely below 50% power.
>
> BTW on a diesel, the combustion is well lean of stoichiometric even at
> the max rated power. *The air intake is not throttle and the
> "throttle" control in a diesel engine is the fuel flow control.
> There's no such thing as lean of peak or best power mixture :-) *You
> reduce the fuel flow and the engine produces less power. *You increase
> the fuel flow and the engine produces more power - until you reach the
> soot limit or other thermo/mechanical limit for the particular engine
> and that's the max rated power.

See this is what I like about this newsgroup. I am always learning
something new. I've never had direct experience with a diesel engine,
although I suspect that there are going to be more of them in cars as
American fuel prices rise.

Phil

[Phil J]

On Apr 13, 8:02*pm, "Peter Dohm" > wrote:

> And the Wilksch Airmotive numbers for specific fuel consumption are
> resoundingly unimpressive for a diesel. *It sure is light though!
>
> Peter- Hide quoted text -
>

Not sure if you are being sarcastic about the weight, but you do
realize the weight was in kilograms, right? 127 kilograms = 279
pounds, which is pretty heavy for a three-cylinder engine.

Phil

[Veeduber]

On Apr 13, 12:29 pm, Denny > wrote:
> Hmmm, My BS meter is twitching...This is a BSFC of ~0.142
>------------------------------------------------------------------------

No it isn't :-)

Jet fuel is about 6.8lbs/gal. 3gph is about 20.5 lbs. SFC for a
turbosupercharged diesel is considerably better than the 0.5 used for
normally aspirated gasoline engines. Even the old Packard radial
diesel did pretty well in the SFC department.

Based on the available data, the figures are credible, in my opinion.

-R.S.Hoover

[[email protected]]

Phil J > wrote:
> On Apr 13, 6:21?pm, M > wrote:
> > On Apr 13, 4:13 pm, Phil J > wrote:
> >
> >
> >
> > > Indus claimed three gallons per hour for a flight from Dallas, Texas
> > > to Lakeland, Florida. ?I would guess that they throttled back to the
> > > leanest possible cruise.
> >
> > No doubt that 3gph figure must be an economic cruise power setting,
> > likely below 50% power.
> >
> > BTW on a diesel, the combustion is well lean of stoichiometric even at
> > the max rated power. ?The air intake is not throttle and the
> > "throttle" control in a diesel engine is the fuel flow control.
> > There's no such thing as lean of peak or best power mixture :-) ?You
> > reduce the fuel flow and the engine produces less power. ?You increase
> > the fuel flow and the engine produces more power - until you reach the
> > soot limit or other thermo/mechanical limit for the particular engine
> > and that's the max rated power.

> See this is what I like about this newsgroup. I am always learning
> something new. I've never had direct experience with a diesel engine,
> although I suspect that there are going to be more of them in cars as
> American fuel prices rise.

Diesel used to be cheaper then gasoline and people started buying
diesel cars.

Diesel now costs about the same as gasoline and people have stopped
buying diesel cars.

Unless the price of diesel drops significantly with respect to gasoline,
there is no reason to think diesel cars will make a comeback.


--
Jim Pennino

Remove .spam.sux to reply.

[Phil J]

On Apr 13, 10:35*pm, wrote:
> Phil J > wrote:
> > On Apr 13, 6:21?pm, M > wrote:
> > > On Apr 13, 4:13 pm, Phil J > wrote:
>
> > > > Indus claimed three gallons per hour for a flight from Dallas, Texas
> > > > to Lakeland, Florida. ?I would guess that they throttled back to the
> > > > leanest possible cruise.
>
> > > No doubt that 3gph figure must be an economic cruise power setting,
> > > likely below 50% power.
>
> > > BTW on a diesel, the combustion is well lean of stoichiometric even at
> > > the max rated power. ?The air intake is not throttle and the
> > > "throttle" control in a diesel engine is the fuel flow control.
> > > There's no such thing as lean of peak or best power mixture :-) ?You
> > > reduce the fuel flow and the engine produces less power. ?You increase
> > > the fuel flow and the engine produces more power - until you reach the
> > > soot limit or other thermo/mechanical limit for the particular engine
> > > and that's the max rated power.
> > See this is what I like about this newsgroup. *I am always learning
> > something new. *I've never had direct experience with a diesel engine,
> > although I suspect that there are going to be more of them in cars as
> > American fuel prices rise.
>
> Diesel used to be cheaper then gasoline and people started buying
> diesel cars.
>
> Diesel now costs about the same as gasoline and people have stopped
> buying diesel cars.
>
> Unless the price of diesel drops significantly with respect to gasoline,
> there is no reason to think diesel cars will make a comeback.
>
> --
> Jim Pennino
>
> Remove .spam.sux to reply.- Hide quoted text -
>
> - Show quoted text -

True. It all depends on the price difference between gasoline and
diesel. But diesels typically get 30-35 percent more miles per gallon
than gasoline. I would think a small diesel in a hybrid would make
for a very fuel-efficient car.

Phil

[buttman]

On Mon, 14 Apr 2008 03:35:04 +0000, jimp sayeth:

>
> Diesel now costs about the same as gasoline and people have stopped
> buying diesel cars.
>
> Unless the price of diesel drops significantly with respect to gasoline,
> there is no reason to think diesel cars will make a comeback.

At least in the past 6 months since I've owned a diesel car, diesel fuel
has always costs much more than regular gas. Right now premium is about
$3.60, and diesel is right around $4.

Usually you take the difference between regular and premium, multiply by
1.5, then add that to the cost of premium to get the approximate price of
diesel.

[[email protected]]

Phil J > wrote:
> On Apr 13, 10:35?pm, wrote:
> > Phil J > wrote:
> > > On Apr 13, 6:21?pm, M > wrote:
> > > > On Apr 13, 4:13 pm, Phil J > wrote:
> >
> > > > > Indus claimed three gallons per hour for a flight from Dallas, Texas
> > > > > to Lakeland, Florida. ?I would guess that they throttled back to the
> > > > > leanest possible cruise.
> >
> > > > No doubt that 3gph figure must be an economic cruise power setting,
> > > > likely below 50% power.
> >
> > > > BTW on a diesel, the combustion is well lean of stoichiometric even at
> > > > the max rated power. ?The air intake is not throttle and the
> > > > "throttle" control in a diesel engine is the fuel flow control.
> > > > There's no such thing as lean of peak or best power mixture :-) ?You
> > > > reduce the fuel flow and the engine produces less power. ?You increase
> > > > the fuel flow and the engine produces more power - until you reach the
> > > > soot limit or other thermo/mechanical limit for the particular engine
> > > > and that's the max rated power.
> > > See this is what I like about this newsgroup. ?I am always learning
> > > something new. ?I've never had direct experience with a diesel engine,
> > > although I suspect that there are going to be more of them in cars as
> > > American fuel prices rise.
> >
> > Diesel used to be cheaper then gasoline and people started buying
> > diesel cars.
> >
> > Diesel now costs about the same as gasoline and people have stopped
> > buying diesel cars.
> >
> > Unless the price of diesel drops significantly with respect to gasoline,
> > there is no reason to think diesel cars will make a comeback.
> >
> > --
> > Jim Pennino
> >
> > Remove .spam.sux to reply.- Hide quoted text -
> >
> > - Show quoted text -

> True. It all depends on the price difference between gasoline and
> diesel. But diesels typically get 30-35 percent more miles per gallon
> than gasoline. I would think a small diesel in a hybrid would make
> for a very fuel-efficient car.

Modern internal combustion engines all have the same efficiency no
matter what the fuel is.

Diesel has about 15% more energy per gallon than gasoline.

So, for equal weight, aerodynamics, and engine power, a diesel car has
a 15% advantage on a per gallon basis.

There are some other minor differences such as a X HP diesel will weigh
a little more than a X HP gasoline engine and slightly different
HP vs RPM curves, etc., but they will all be trivial to the overall
milage numbers over any significant amount of time.


--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

It takes more crude oil to make a gallon of diesel than a gallon of
gasoline.

I don't have any figures immediately available, but I expect there's
no real advantage in going to diesel on a miles per barrel of oil
basis. It might seem that way on a dollars at the filling station
basis, but that's due more to tax policy than energy efficiency.


On Apr 14, 6:08 am, Phil J > wrote:
>
> True. It all depends on the price difference between gasoline and
> diesel. But diesels typically get 30-35 percent more miles per gallon
> than gasoline. I would think a small diesel in a hybrid would make
> for a very fuel-efficient car.
>
> Phil

[Capt. Geoffrey Thorpe]

> wrote in message
...
<...>
> Modern internal combustion engines all have the same efficiency no
> matter what the fuel is.

If that were true, I wouldn't have a job...

>
> Diesel has about 15% more energy per gallon than gasoline.
>
> So, for equal weight, aerodynamics, and engine power, a diesel car has
> a 15% advantage on a per gallon basis.

Nope. A "typical" diesel has a higher compression ratio - that increases the
efficiency. They "typically" aren't throttled which reduces pumping work and
increases the efficiency (more a factor for automobiles than aircraft which
tend to run at higher power (except when doing pattern work)). The
stratified nature of the combustion reduces the heat loss to the walls /
coolant which improves the efficiency.

On the other hand, the higher pressures require stronger stuctures, and the
stratified combustion reduces the abilty of the engine to use the air which
reduces power /displacement and power / weight which leads to lower
"installed" efficiency and is why turbos are so popular on diesels.

The final advantage then depends on a lot of variable (including how the
engine is used) but it will typically exceed the simple advantage of the
increased energy density of the fuel.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[Capt. Geoffrey Thorpe]

"Phil J" > wrote in message
...

True. It all depends on the price difference between gasoline and
diesel. But diesels typically get 30-35 percent more miles per gallon
than gasoline. I would think a small diesel in a hybrid would make
for a very fuel-efficient car.

++++++++++++++++++++++++++++++++

You don't get the same payback from the hybrid with a diesel since they
don't suffer as much of an efficiency loss at lower loads that typical
gasoline engines do.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[[email protected]]

Capt. Geoffrey Thorpe <The Sea Hawk At Wow Way D0t C0m> wrote:
> > wrote in message
> ...
> <...>
> > Modern internal combustion engines all have the same efficiency no
> > matter what the fuel is.

> If that were true, I wouldn't have a job...

> >
> > Diesel has about 15% more energy per gallon than gasoline.
> >
> > So, for equal weight, aerodynamics, and engine power, a diesel car has
> > a 15% advantage on a per gallon basis.

> Nope. A "typical" diesel has a higher compression ratio - that increases the
> efficiency. They "typically" aren't throttled which reduces pumping work and
> increases the efficiency (more a factor for automobiles than aircraft which
> tend to run at higher power (except when doing pattern work)). The
> stratified nature of the combustion reduces the heat loss to the walls /
> coolant which improves the efficiency.

> On the other hand, the higher pressures require stronger stuctures, and the
> stratified combustion reduces the abilty of the engine to use the air which
> reduces power /displacement and power / weight which leads to lower
> "installed" efficiency and is why turbos are so popular on diesels.

> The final advantage then depends on a lot of variable (including how the
> engine is used) but it will typically exceed the simple advantage of the
> increased energy density of the fuel.

Granted, but not by a whole lot for a car application with both engines
using all the techo advantages available today and constrained by
EPA requirements over 100,000 miles of usage.

Comparing anything other than car engine to car engine is apples and
oranges.

For aircraft applications, the biggest motivator is the fact that
AVGAS has become a boutique fuel with a good chance of disappearing
in the future while JET-A will always be around short of Armageddon.


--
Jim Pennino

Remove .spam.sux to reply.

[Bertie the Bunyip[_24_]]

Buttman > wrote in
:

> On Mon, 14 Apr 2008 03:35:04 +0000, jimp sayeth:
>
>>
>> Diesel now costs about the same as gasoline and people have stopped
>> buying diesel cars.
>>
>> Unless the price of diesel drops significantly with respect to
>> gasoline, there is no reason to think diesel cars will make a
>> comeback.
>
> At least in the past 6 months since I've owned a diesel car, diesel
> fuel has always costs much more than regular gas. Right now premium is
> about $3.60, and diesel is right around $4.
>
> Usually you take the difference between regular and premium, multiply
> by 1.5, then add that to the cost of premium to get the approximate
> price of diesel.
>

Or, if you had half a brain, you coud look at the price on the hoarding
outside the station.


Bertie