Steve are you one the list and sent something to Mr. Klein?
In any event I have a couple of questions for Mr. Klein.
1)How many cylinders?
2)What would one of your 300 cubic inch diesels weigh?
3)Is that with an aluminum block?
4)What is the BSFC at 75% power.
5)Has it run at 75% power for 150 hours continuously?
6)What is the projected number of hours in aircraft service before it needs
to be overhauled?
7)Do you have a plot of the torque variation as a function of crankshaft angle?
I ask because the Renault aircraft diesel was very hard on propellers.
8) What is the perfected cost for an aircraft version.
As back ground info on the rotary. The bare engine block weighs
about 190 pounds with cast iron end housings. About 140 pounds with
aluminum end housings. The firewall forward weight for a 190 pound NA engine
including prop, motor mount and cooling system is about 300 pounds.
Thousands of hours have been accumulated on 200 HP rotaries normally aspirated
in aircraft service. That is 200 HP take off power and 65% to 75% cruise power.
The engine short block is 12 inches wide 14 inches tall and 18 inches long.
Typically the cooling system fits in the cowl with the engine reducing
the aerodynamic drag.
The retail price of the new bare 240 HP RX8 engine is $5800.
Over two million Mazda rotaries have been built and sold. Prop gear
boxes are $2500 to $6500.
The turbine we would be using is off the shelf and incorporated with the turbo charger.
Weight of a TO4 turbocharger is 16 pounds. Weight of the turbine RPM reduction
unit is still an unknown but my guess is less than ten pounds. Prop speed reduction
gear boxes weigh from 35 pounds to 45 pounds depending on the manufacturer.
New turbo chargers retail for less than $1000 in quantities of one.
Certain used Mazda engines are already equipped with turbo chargers.
The rotary is capable of running on jet A as well as auto fuel, 87 octane and
100LL aviation fuel.
HP of the turbo compound version using the 1954 TC technology level will be
300 HP based on a peripheral port 250 HP normally aspirated rotary flat rated up
to 25,000 foot altitude. Projected BSFC is .37. With further development
taking advantage of the lack of exhaust valves in the rotary I expect 325
HP and a BSFC of .34.
Paul Lamar
Jeffrey Klein wrote:
Steve,
Mr. Lamar is working on an interesting and potentially useful engine.
I don’t say so just to be nice, but because when compared to the engines
currently available for general aviation, his may be better. General
aviation engines generally retail, new, for over $100 per horsepower.
With the turbine, Mr. Lamar’s engine will likely not be less expensive.
It is my understanding that one of the reasons for the high costs for
aviation engines is the small number of them produced. The Compound
turbo Wankel may be competitive in the aviation market against common
engines of our time, but will it be any less expensive?
As to weight, this is partly a function of power density. Current
aviation power plants can produce maximum power only for short periods,
like my IO 520 K (Continental) which has a max rated power of 300 hp @
sea level for no longer than 5 minutes. 520 cu inches for 300 hp! It
weighs, fully installed, about 500 #. This is over 1 # per cu inch.
The Wankle with turbine will weigh less, and probably cost more, and
provide customary diesel fuel efficiency with 100 octane gasoline. This
fuel has been speculatively declared to be nearly extinct, and is
already less widely available than jet fuel, which is unlikely to burn
well in a Wankel, although it can be, and has been, done. A true
compression ignition diesel can easily burn jet fuel.
The jet fuel burning LIM type diesel will not weigh any more than its
contemporary competitor from Lycoming, Continental or even Franklin,
because it will be smaller, only 300 cu inches. It normal operating
speed is just right for a propeller, so no transmission will be needed.
Even at 1.5 # per cu inch, there would be a weight advantage!
The Lamar approach is attractive and feasible, but it is not the only
approach, especially when considering which fuel is more available and
less expensive. I still expect an aviation engine with BSFC of no more
than 0.34, which can be run at full power all the time, using widely
available jet fuel.
Respectfully,
Jeffrey
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