diesel 160-200HP engines

Steve Campbell wrote:
That is a pretty over the top link, but politics aside, how many
homebuilders will spend that much for an engine? The cost of Deltahawk's
200 hp version was originally projected to be around 12 k$. (It was also
going to weigh about 100 lbs less than an IO-360.) It is now close to 30 k$
and who knows what it will be by the time that you actually buy one. There
may well be significant reliability advantages, much lower operating cost
advantages, and just the basic coolness of the gadget, but still, I don't
have that kind of money for an engine with no service record, no parts
network, no experienced repair stations, etc. etc. God bless for getting
this thing as far as they have, but I would expect that if this thing ever
goes into production, its primary application will be in a certified
aircraft where the cost of the powerplant is a small part of the total cost.
Steve


I'll have to agree there. When I drove big trucks, one of the old time
guys was fond of saying that not just anyone could be a diesel mechanic.
For all the supposed simplicity, those things are finicky creatures.

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

In m Ernest Christley
wrote:

I'll have to agree there. When I drove big trucks, one of the old
time guys was fond of saying that not just anyone could be a diesel
mechanic. For all the supposed simplicity, those things are finicky
creatures.

I agree. What will be needed are mechanics who will be required to have
a certain level of training and/or experience, maintain a level of
currency, and receive adequate training on the specific equipment before
they can work on it. Sounds kind of like an A&P mechanic.

FWIW, the "current" technology aircraft engines can also be finicky
creatures, for all their supposed simplicity.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

All,

In addition to being an lurker and occasional poster on RAH, I also
happen to be one of the engineers responsible for the DeltaHawk (or the
sole reason the engine hasn't been in full production for the last 3
years according to the marketing guy). In any case, as this is one of
my few areas of RAH expertise, I'd be happy to answer any questions that
people may have regarding the project.

The web site

www.deltahawkengines.com

is generally pretty up to date, but there are certainly always specific
questions that a FAQ won't answer.

Dave Driscoll
DeltaHawk LLC

geo wrote:

Here's an interesting new diesel engine with much lower operating costs.
Looks like it would fill the bill for a Glass Goose (which I'm considering)
very nicely. Waddya think? http://www.deltahawkengines.com/object00.htm

OK, cool. I got some questions.

The site says the engine is not suitable for aerobatic use. What are the
operating limits of the engine, specifically the inverted V-4.

Pete


"Dave Driscoll" wrote in message
...
In addition to being an lurker and occasional poster on RAH, I also
happen to be one of the engineers responsible for the DeltaHawk (or the
sole reason the engine hasn't been in full production for the last 3
years according to the marketing guy). In any case, as this is one of
my few areas of RAH expertise, I'd be happy to answer any questions that
people may have regarding the project.

Dave, I like the Deltahawk package the way it is, but I do have a
hypothetical question.

What are the merits, of lack thereof, of using an electrically boosted
turbocharger to supply combustion air for starting or flight idle? It would
seem, at first glance, to be a simpler and lighter solution than using both
a roots supercharger and a turbo in series.

Bill Daniels


"Dave Driscoll" wrote in message
...
All,

In addition to being an lurker and occasional poster on RAH, I also
happen to be one of the engineers responsible for the DeltaHawk (or the
sole reason the engine hasn't been in full production for the last 3
years according to the marketing guy). In any case, as this is one of
my few areas of RAH expertise, I'd be happy to answer any questions that
people may have regarding the project.

The web site

www.deltahawkengines.com

is generally pretty up to date, but there are certainly always specific
questions that a FAQ won't answer.

Dave Driscoll
DeltaHawk LLC

geo wrote:

Here's an interesting new diesel engine with much lower operating costs.
Looks like it would fill the bill for a Glass Goose (which I'm
considering)
very nicely. Waddya think? http://www.deltahawkengines.com/object00.htm

Bill,

I love questions like this, you've already done the heavy lifting and
pretty much nailed the merits. The merits start to look even better
when you examine the possibilities of putting a clutched shaft on your
existing turbo and electrically spin the compressor side as required
(reduces weight, gains you the HP that is always being sucked up by the
blower which is compressing air at a much lower efficiency than the
turbo, etc.) There are also a mess of other possibilities that while
more complex from an engineering standpoint offer "better" solutions for
certain mission profiles. These include compressed air starts, fully
electrical turbos, clutched superchargers, centrifugal or screw
compressor supercharges instead of roots type, the list goes on.

The selection of our current solution was a combination of the desire
for mechanical redundancy, the use of off the shelf parts (off the shelf
5 years ago mind you), and the need for something that didn't require a
huge amount of engineering effort to shoe horn into our package. That
said, undoubtedly this is one of the areas that will see modification as
time passes, and it wouldn't surprise me in the least if 5 years from
now there is a DeltaHawk model that in addition to the electric turbo
has full FADEC fuel control, an electric water pump, and an integrated
starter/generator. Imagine what that will do to the weight and fuel
efficiency. Additionally, due to the modular design of all of these
components on the DeltaHawk, all of these items are a external to the
engine case and for the most part are a bolt on proposition.

Dave Driscoll
DeltaHawk LLC


Bill Daniels wrote:

Dave, I like the Deltahawk package the way it is, but I do have a
hypothetical question.

What are the merits, of lack thereof, of using an electrically boosted
turbocharger to supply combustion air for starting or flight idle? It would
seem, at first glance, to be a simpler and lighter solution than using both
a roots supercharger and a turbo in series.

Bill Daniels


"Dave Driscoll" wrote in message
...


All,

In addition to being an lurker and occasional poster on RAH, I also
happen to be one of the engineers responsible for the DeltaHawk (or the
sole reason the engine hasn't been in full production for the last 3
years according to the marketing guy). In any case, as this is one of
my few areas of RAH expertise, I'd be happy to answer any questions that
people may have regarding the project.

The web site

www.deltahawkengines.com

is generally pretty up to date, but there are certainly always specific
questions that a FAQ won't answer.

Dave Driscoll
DeltaHawk LLC

geo wrote:



Here's an interesting new diesel engine with much lower operating costs.
Looks like it would fill the bill for a Glass Goose (which I'm


considering)


very nicely. Waddya think? http://www.deltahawkengines.com/object00.htm

Pete,

This is a very complex issue which involves a bunch more variables than
the three big ticket ones I'm going to mention (fuel delivery for one).
Internal to the engine, crankshaft stresses, bearing loads, and oil
scavanging/delivery are the three largest concerns for Aerobatic class
engines. The first two are also significantly affected by what prop is
being used (low inertia, high inertia), however based upon empirical
comparison with other engines which are Acrobatically rated, the
DeltaHawk is in pretty good shape on those two fronts (our crank is
stronger and we have more bearing area). Oil however is another story,
the current Deltahawk's are only designed with oil scavenging occurring
in one direction, down. There are separate sump systems for the upright
and inverted models and while they work fine in their intended
orientation, we have not done significant negative g testing with either
configuration. It is our intention to pursue this type of testing in
the future, as well as test a configuration of the engine with both sump
systems active, however to date we have not.

Currently the engine is intended to duplicate the performance of the
Normal (+3.8,-1.52) and Utility (+4.4,-1.76) classes (I say mimic,
because all the initial engines will be registered on experimental class
aircraft and limitations will be set by the builder) and our flight
testing thus far has not uncovered any problems with these performance
envelopes.

Hope that answered your question.

Dave Driscoll
DeltaHawk LLC



Pete Schaefer wrote:

OK, cool. I got some questions.

The site says the engine is not suitable for aerobatic use. What are the
operating limits of the engine, specifically the inverted V-4.

Pete


"Dave Driscoll" wrote in message
...


In addition to being an lurker and occasional poster on RAH, I also
happen to be one of the engineers responsible for the DeltaHawk (or the
sole reason the engine hasn't been in full production for the last 3
years according to the marketing guy). In any case, as this is one of
my few areas of RAH expertise, I'd be happy to answer any questions that
people may have regarding the project.

Thanks for the nice reply. Now I have another question that, while it is about engineering, also relates to a market opportunity. First a bit of background - forgive me if you already know all this.

I fly gliders which are most often hauled into the air by a tow plane. Now glider tugs belong to the same engineering category as tractors used for tractor pull competitions - brute force and not much sophistication. For spark ignition, air cooled engines, glider towing is brutal work - red line temps followed by rapid chill down five or six times an hour.

Sometimes, the tug is asked to tow a 1300 pound glider into a mountain wave at 15,000 feet which can really tax the engine's cooling capacity as well as high altitude performance.

A Piper Pawnee with a 260 HP Lycoming O-540 has enough power for the job but, without some VERY careful operating techniques, overhauls come up often. Fuel consumption on a Lyc O-540 runs over 20 GPH. All this makes glider tows far more expensive than they should be. A Pawnee with a standard 2-blade prop is also noisy enough to prompt airport neighbor complaints.

A glider tug tows at about 65 knots and speeds above that are unimportant. The power package needs to produce maximum thrust for the HP at that airspeed. This fact suggests that a large, slow turning prop or perhaps a ducted fan could do the same job with much less horsepower - and noise.

A 160 - 200 HP Deltahawk looks like a perfect match for the job if it were matched to the correct prop. Would you please comment on this application?

Bill Daniels


"Dave Driscoll" wrote in message ...
Bill,

I love questions like this, you've already done the heavy lifting and pretty much nailed the merits. The merits start to look even better when you examine the possibilities of putting a clutched shaft on your existing turbo and electrically spin the compressor side as required (reduces weight, gains you the HP that is always being sucked up by the blower which is compressing air at a much lower efficiency than the turbo, etc.) There are also a mess of other possibilities that while more complex from an engineering standpoint offer "better" solutions for certain mission profiles. These include compressed air starts, fully electrical turbos, clutched superchargers, centrifugal or screw compressor supercharges instead of roots type, the list goes on.

The selection of our current solution was a combination of the desire for mechanical redundancy, the use of off the shelf parts (off the shelf 5 years ago mind you), and the need for something that didn't require a huge amount of engineering effort to shoe horn into our package. That said, undoubtedly this is one of the areas that will see modification as time passes, and it wouldn't surprise me in the least if 5 years from now there is a DeltaHawk model that in addition to the electric turbo has full FADEC fuel control, an electric water pump, and an integrated starter/generator. Imagine what that will do to the weight and fuel efficiency. Additionally, due to the modular design of all of these components on the DeltaHawk, all of these items are a external to the engine case and for the most part are a bolt on proposition.

Dave Driscoll
DeltaHawk LLC


Bill Daniels wrote:

Dave, I like the Deltahawk package the way it is, but I do have a
hypothetical question.

What are the merits, of lack thereof, of using an electrically boosted
turbocharger to supply combustion air for starting or flight idle? It would
seem, at first glance, to be a simpler and lighter solution than using both
a roots supercharger and a turbo in series.

Bill Daniels


"Dave Driscoll" wrote in message
...
All,

In addition to being an lurker and occasional poster on RAH, I also
happen to be one of the engineers responsible for the DeltaHawk (or the
sole reason the engine hasn't been in full production for the last 3
years according to the marketing guy). In any case, as this is one of
my few areas of RAH expertise, I'd be happy to answer any questions that
people may have regarding the project.

The web site

www.deltahawkengines.com

is generally pretty up to date, but there are certainly always specific
questions that a FAQ won't answer.

Dave Driscoll
DeltaHawk LLC

geo wrote:

Here's an interesting new diesel engine with much lower operating costs.
Looks like it would fill the bill for a Glass Goose (which I'm
considering)
very nicely. Waddya think? http://www.deltahawkengines.com/object00.htm

On Fri, 26 Mar 2004 22:26:50 -0600, Dave Driscoll
wrote:

I'd be happy to answer any questions that
people may have regarding the project.


Hi Dave

How do you get a diesel restarted in the air if you happen
to have multiple fuel tanks and run one dry so the injection
system gets air in it? Is there a way around this problem?

Jim

Jim,

The engine is designed to be fairly fault tolerant of air bubbles in the
low pressure fuel lines (the returns from the pump element gallery are
positioned above the high pressure gallery inlet etc.) and will continue
to deliver solid fuel through the high pressure lines even with bubbles
in the low pressure ones. It will also repurge the high pressure lines
even in the event that you run them completely dry. You simply have to
reintroduce fuel to the system and keep spinning the prop at greater
than 150 rpm. How long it takes for a restart is based upon how dry the
system was and how fast you can spin the prop. This however is not a
good practice as the high pressure pumps will be operating without
lubrication on the top side until the fuel is reintroduced. The
collective thoughts of the group are that you can certainly get away
with it a couple of times, but better be thinking about inspecting the
high pressure plungers after the 2nd full dry restart.

Dave Driscoll
DeltaHawk LLC

jpollard###mnsi.net wrote:

On Fri, 26 Mar 2004 22:26:50 -0600, Dave Driscoll
wrote:



I'd be happy to answer any questions that
people may have regarding the project.




Hi Dave

How do you get a diesel restarted in the air if you happen
to have multiple fuel tanks and run one dry so the injection
system gets air in it? Is there a way around this problem?

Jim