Bill,
Tailor made application for the DeltaHawk. The liquid cooling will do
wonders for evening out the thermal loading, our flight testing
indicates full power to beyond 18,000 feet, and the engines flat torque
profile "should" take care of your HP needs at lower airspeeds. I say
"should" because we won't really know, without taking a much closer look
at your application. However, the 160 HP DeltaHawk performs exactly the
same as a 200 HP IO-360 in takeoff and climb out in a side by side
comparison using the identical aircraft with different engine
installations (two Velocity RG's). Based upon that empirical data, I'd
venture that the 200 HP DeltaHawk will compare quite favorably
performance wise with the Lycoming and further bring both significant
weight (50-70 lbs.) and fuel savings to the table.
Dave Driscoll
DeltaHawk LLC
Bill Daniels wrote:
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