It is probably the highest power to weight propeller driven aircraft to
have ever flown.
This is due entirely to the fact that the Mazda rotary engine is such a
high power to weight ratio engine. 650 HP at under 200 pounds is
remarkable.
High power to weight ratio aircraft engines have been essential from the
very beginning of flight. Prior to the Wright Brothers flying professor
Langley of the Smithsonian Institution appreciated the need for a high
power to
weight ratio engine.
Quote Aircraft Piston Engines Herschel Smith
"Charles M. Manly, then a recent Cornell graduate, was assistant to
Prof. Samuel P. Langley of the Smithsonian Institution, the best-known
and best-financed aerial experimenter in the world at the time. As
early as 1898, only the lack of a suitable engine seemed to stand
between Langley and success. However, overcoming this lack proved to be
a formidable task. No engine builder in Europe or America could supply a
light enough engine of sufficient power, and so Manly reluctantly took
on the task of designing one.
Building on the work of Stephen M. Balzer
of New York, he turned out a 5-cylinder radial engine of 540 cu in.
(8.85 L) that gave a reliable 52 hp at 950 rpm. Despite being
water-cooled, it weighed only 136 lb exclusive of water and radiator. To
make such a big engine so light, Manly went to remarkable extremes. The
cylinders, made with a steel shell for strength and a cast-iron liner
for good lubrication, had a total wall thickness of only one eighth of
an inch.
The sheer workmanship required to machine closed-end steel
shells 5 in. in diameter, 9 in. long, and 1/16 in. thick on 1900
equipment is staggering. On top of this, Manly and his staff had to make
equally thin cast-iron sleeves accurately enough to be a shrink fit in
these shells. The water jackets were made of sheet steel 0.020 in.
thick, brazed to the cylinders. This, too, was a formidable job; it is
extremely hard to bring two pieces of metal of very different
thicknesses to red heat without having the lighter piece burn before the
heavier one gets up to temperature. "
This type engine went on to dominate the aircraft engines used in World
War I.
Essential to the Wright brothers success was their designing and
building their own high power to
weight ratio (at the time) 4 cylinder in-line engine.
Since that time billions of dollars have been spent by the aircraft
engine industry world wide in the search for higher and higher power to
weight ratio engines. The TTC Mazda Wankel is the beginning of
the end for aircraft piston engines and the small aircraft turbo prop
engine. Only a small gain in BSFC remains to be invented.
Paul Lamar
Paul,
650 HP at near 200 lbs engine weight really is remarkable.
Following below is a quote from Wikipedia on the Formula 1 engine of
2006 that were used till 2013. V8, 2,4 liter. 19,000 rpm, 750 hp, 95 kg
minimum weight.
I am not sure what the actual weight really was. Anyway, 95 kg is close
to 210 lbs. 2.4 liter is close to the 2.6 liter Mazda RX8, the weight
compares close too. In other words the Mazda is as good or better than
the F1 of 2006 that needed 1900 rpm to get the 750 hp. By linear
deduction 650/750 hp *19,000 means 16,500 or near there would be needed
for 650 HP. Including the somewhat higher displacement 15,200 rpm are
required for to get 650 HP.
The life of the F1 was some 2 races or roughly 1000 km or there abuts.
No comparison really regarding endurance, and really in fuel use too as
the F1 had an efficiency near or under 10% as far as I am aware of. If
someone has more accurate numbers please let us know.
The difference really is the high mean effective pressure the Wankel can
tolerate. As Paul always puts it, the RPE is a 'hand grenade' and such
pressures or would explode.
At equal combustion pressures to the RPE the Wankel is just loafing.
It's strength really is high speed and high combustion pressure
tolerance. An ideal aircraft engine that is low on fuel use compared to
turbines. As aircraft engine for up to 500 hp or perhaps more nothing is
better. A twin engine of total 1000 - 1200 hp would serve many business
aircraft.
>From Wiki:
(
http://www.formula1-dictionary.net/engine_rule_changes_history.html
<http://www.formula1-dictionary.net/engine_rule_changes_history.html>)
*For 2006*, 2400cc engine with 8 cylinders in a 90° V bank, each one
with 2 inlet and 2 outlet valves with a 98 mm maximum circular bore,
which imply a 39.7 mm minimum stroke. An engine must weigh at least
95kg. Limited to be built with Aluminium alloys (with ceramics, metal
matrix and magnesium alloys forbidden). Variable geometry intake and
output systems forbidden. Each cylinder can have only one fuel injector
and a single plug spark ignition. This is leading to a power reduction
of around 20% from the three litre engines. Gearbox must last 4
consecutive races.
750 hp at 19000+ rpm (Toyota)
Rolf Pfeiffer.
95 Kg is 202 pounds. Two pounds heavier than ours with that 100 million
dollar engine. Assume our engine cost $20,000 that is only 2% of the cost
of the F1 engine.
These F1 engines are not suitable for aircraft as they are running at
up to 19,000 RPM. It takes a very very heavy gear box indeed to reduce
the prop RPM to 2500.
With expensive beryllium aluminum rotors we could run at only 16,000 RPM
and double the HP to 1,300 HP.
--------------------------------------------------------------------------------------
Some of the guys in the shop questioned my claim for the world record
in power to weight aircraft. They brought up the Pogo so I researched
it. I had this book called The World Worst Aircraft.
"In March 1951, less than a year after the start of the Korean War, the
Navy
ordered prototype VTOL fighters from both Lockheed and Convair under the
designations XFV-I and XFY-I. Both would be designed around the huge,
6825 hp
Allison XT40A-16 double turboprop engine, and whichever design proved
itself
superior, would be ordered into production."
The Lockheed version was never able to take off as it was 2000 pounds
heavier than the Convair versions.
The Lockheed version weighed 16,221. We beat that by a bunch. That is
2.376 pounds per HP. Ours weighs 1,175 pounds with the pilot and our HP
is 650 so the TTC engine is 1.81 pounds per HP.
The Convair version was lighter and that weighed 14.250 which
is 2.09 pounds per HP. We beat that too.
These are turbo prop airplanes so that is very significant
so that also backs up my claim that the TTC engine has a higher
power to weight ratio than turboprop engines as well.
So as I said before we have a world record for power to weight
ratio of propeller driven airplanes.
I am going to suggest to Dan that we go for an altitude record as well
as the time to climb to 3000 meters record.
Paul Lamar
Paul,
Once at an Oshkosh forum, Tracy was telling about racing his 3 rotor
Cosmo and
I ask him what the highest RPM he had ever reached.
He answered 19,000!!
Dave James
He was maybe making a joke :-)
No way will cast iron rotors spin that fast.
The engine will seize around 11,000.
Let alone he was taking about racing an airplane so it must have had
a six to one gearbox. Highly unlikely :-)
We discussed beryllium aluminum rotors on here years ago.
Jeff Doodridge also tried to build titanium rotors but I do not
know if they were tested. Tracy did not get a set.
Other alloys other than iron expand more so allowances have to be
made for that,
Paul Lamar
Dan Duncan had gotten up past 13,000. He said he was balancing his
engines quite a bit tighter than the factory did it.
Dave Klingler
Consider the source :-)
The problem is not balance. It is centrifugal load on the rotor bearing.
That is why we run 150 psi oil pressure in the TTC engine.
Paul Lamar
I understand your point about the rotor bearing, but the source did
deliver close to ninety aviation engines, which he was able to prove in
court when the Oklahoma AG charged him with a count of mail fraud for
every letter in his file cabinet. Had Dan not sold an engine to that
doctor in Oklahoma, he’d have built a lot more than that.
He ran a couple of NASA SBIR programs to determine possible redlines
and TBO’s. He got that 13,000 redline number by running a few engines
to destruction, but he told me he’d stopped the TBO program once the
engines proved they’d make it past 3000 hours.
Dave Klingler
Is the Turbo Raven your target (flying performance weight=1900lbs,
750hp, 2800lbs thrust):
http://www.waynehandley.com/
Cheers,
Matt Prather
We got that beat. 1175 pounds with pilot and 650 HP.
The raven is 2.53 pounds per HP.
Ours is 1.8 pounds per HP.
We figure it will climb vertically at 175 MPH.
Only the turbo prop Convair Pogo came closer at just over 2 pounds per HP.
It weighed 15,000 pounds and took of vertically.
We flew too :-)
https://www.youtube.com/watch?v=0LFXE6EBLLs
Paul Lamar
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