Hi, Paul....I thought you might find this interesting. Delta Hawk
reportedly just had their first flight, and are getting ready to deliver
engines to those on the waiting list....Sounds like they haven't even found
out how long the engine will last.....If it flys once, sell it? Paul
Conner.....dedicated rotary enthusiast.
I totally agree. Lots of Chevy V8's including the Orenda have flown
and where are they now? Packard built an aircraft diesel in 1931 and what
happened to it? Junkers built many diesel aircraft engines in WW II and where
are they now? Renault recently built a diesel, flew it but where is it now? Continental
got 10 million dollars of our tax money, displayed few wooden mockups and where
is it now? Delta Hawk needs to comes up with many thousands of dollars
to test several engines to 2000 hours TBO. I'll believe it when I see it.
The Delta Hawk is based on the roots blown GM V6 to V12 two cycle diesel
design which GM no longer makes. It should work if they designed it right.
However I suspect the fuel consumption of the Delta Hawk engine will be higher
than any four cycle diesel negating the diesel advantage.
Paul Lamar
A bit more about the Delta Hawk. The GM two cycle engine I mentioned has an advantage
over the Delta Hawk as the GM engine had poppet exhaust valves improving
the scavenging. The Delta Hawk as I recall had
simple loop scavenging. In other words the exhaust and intake ports were
piston ported. This will lead to more fuel consumption. The up side
is there are no exhaust valves... just like the rotary.
If you want to read up on these types of diesel engines get a copy
of Charles Fayette Taylor's books The Internal Combustion Engine
In Theory and Practice. Volumes 1 and 2.
The GM 8V-71 TA V8 version put out 370 HP from 568 cubic inches at 2100 RPM
and weighed 2415 pounds or 6.52 pounds per HP. This is a relatively
low number for diesel engines. It will take
some very clever engineering indeed to make the engine reliable
at a lower weight per HP. GM spent millions over dozens of years developing
this engine. There have been no break throughs in materials
in the past twenty years that will substantially reduce the weight
per HP of any piston engine. Frankly I am extremely skeptical.
An aircraft engine has a comparably duty cycle to a this type of truck
and commercial boat engines.
Paul Lamar
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