Pounds per Horsepower Listing

Dan Thomas said:
Better yet: Harmon Rocket, 4.5 lb/hp.

http://www.harmonrocket3.com/HR3_Specs.html

ROC 3600 FPM at gross.

Beat that, will you.

Dan
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HARMON ROCKET III Specs

Span…………………………………………20’ Fuel Capacity…………47 Gal
Length……………………………………21’6” Seats………………………………1
Height……………………………………5’6” Power………………………………Lyc IO-540, 400HP at 2900Rpm
Wing area……………………………99Sq Ft Propeller……………………Hartzell 78”,3 Blade
Empty Weight……………………1080Lbs Cruse Speed 75%……260 MPH
Gross Weight……………………1800Lbs Econ. Cruse 55%……230 MPH
Useful Load………………………720Lbs Redline…………………………310 MPH
Power Loading…………………4.5Lbs/Hp Stall………………………………58 MPH
Wing Loading……………………18 Lbs/Sq Ft Rate of Climb S/L………3600 FPM (Gross)

I seriously question the 58 MPH stall speed...
 
N801BH said:
HARMON ROCKET III Specs

Span…………………………………………20’ Fuel Capacity…………47 Gal
Length……………………………………21’6” Seats………………………………1
Height……………………………………5’6” Power………………………………Lyc IO-540, 400HP at 2900Rpm
Wing area……………………………99Sq Ft Propeller……………………Hartzell 78”,3 Blade
Empty Weight……………………1080Lbs Cruse Speed 75%……260 MPH
Gross Weight……………………1800Lbs Econ. Cruse 55%……230 MPH
Useful Load………………………720Lbs Redline…………………………310 MPH
Power Loading…………………4.5Lbs/Hp Stall………………………………58 MPH
Wing Loading……………………18 Lbs/Sq Ft Rate of Climb S/L………3600 FPM (Gross)

I seriously question the 58 MPH stall speed...
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I wonder about the HP rating of the IO-540 also.
 
FORANE said:
I wonder about the HP rating of the IO-540 also.
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I'm with you there. I don't even see any IO540 listed over 350 horse. But none of them show RPM limit as high as 2900 either
 
bnt83 said:
I'm with you there. I don't even see any IO540 listed over 350 horse. But none of them show RPM limit as high as 2900 either
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There isn't. There also isn't one rated for 2900 RPM.

But in the experimental world with 10:1 pistons, a bigger cam, some head work, 2900 RPM... yeah, it'd be doable.
 
Flybaby is 9.7 lbs per HP. A real powerhouse.
 
I don't know much about ultralights, but have heard of guys putting relatively big HP into pretty light airframes. How do they stack up here?
 
I just wanted to compare the usual old spam cans against each other. Experimental are a all over the place.
 
I wish each of you guys could experience the acceleration and takeoff of a lightly loaded jet. At max gross takeoff weight the thrust to weight ratio is roughly 1:2, that decreases to roughly 1:1.5 at lighter weights. Yee Haw!
 
Geico266 said:
What? No RV-10? :mad:
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Do you see any experimentals? I'm not going to account for every possible RV configuration... This is o'l certificated comparison with the majority being spam cans. The data is easy to find at FAA.gov
 
I think the Cessna 210F has one of the highest service ceilings for normally aspirated certificated spam can around.
 
bnt83 said:
I think the Cessna 210F has one of the highest service ceilings for normally aspirated certificated spam can around.
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Yes, BUT the RV-10 goes to 450 safely as long as the pilot wears a real tight pair of yoga pants.
 
So the max takeoff weight of an RV10 being 2700 pounds and powered anywhere from 210 to 260 horsepower typical = 12.857 to 10.384, which is better than a Cessna 350 at its best and as low as a Cessna 182P at its worst.
 
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bnt83 said:
So the max takeoff weight of an RV10 being 2600 pounds and powered anywhere from 210 to 260 horsepower typical = 12.380 to 12.000, which is lower than the V35B at its best and as low as a Cherokee 235 at its worst.
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95% of the RV-10's are powered by IO-540's rated at 260 HP. Gross weight is 2,700 lbs. That gives us 10.38 lbs/hp...3rd down on that list.
 
RV10flyer said:
95% of the RV-10's are powered by IO-540's rated at 260 HP. Gross weight is 2,700 lbs. That gives us 10.38 lbs/hp...3rd down on that list.
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I goofed the calc on that, good catch. All weights shown are takeoff weights. It looked to me like that's 2600 FWIW.
 
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Dan Thomas said:
Better yet: Harmon Rocket, 4.5 lb/hp.

http://www.harmonrocket3.com/HR3_Specs.html

ROC 3600 FPM at gross.

Beat that, will you.

Dan
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Easy, just put a turbine out front. The Turbine Raven

In 1998, with sponsorship by ORACLE, and seeking an even more impressive airshow aircraft, Wayne set out to create the exceptional Oracle Turbo Raven which was the world’s only aerobatic aircraft with a thrust to weight ratio higher than one (more thrust than weight). Teaming up with Richard Giles of Akrotech, and AgAir Systems, the ORACLE Turbo Raven came to life. The composite airframe based on the G-202 design had an empty weight of only 1,600 pounds (725 kg) and was fitted with a 750 horsepower (560 kW) Pratt & Whitney PT6A-25C turboprop that generated 2,800 pounds (12,500 N) of thrust which gave the aircraft a power loading of less than 2.7 lb/hp at ready to fly weights. With this unheard of power loading the Oracle Turbo Raven could fly straight up, hover in mid-air, back up, stop, and then accelerate straight up out of the hover. The aircraft also had enough power that it could recover from flat spins simply by flying out of them with the nose still on the horizon. With a top speed of 300 mph (480 km/h) and a roll rate of 450 degrees per second this aircraft was quite impressive.
 
Since we're throwing out non-standards... ;)

Cessna 310 Colemill executive 600. 5200 lbs gross, 600 HP.

8.67 lbs/hp at gross.

Get it down to 4500 lbs (pretty easy) and 7.5 lbs/hp. :)
 
Ted DuPuis said:
Since we're throwing out non-standards... ;)

Cessna 310 Colemill executive 600. 5200 lbs gross, 600 HP.

8.67 lbs/hp at gross.

Get it down to 4500 lbs (pretty easy) and 7.5 lbs/hp. :)
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Looks like most standard GA twins aren't much different than the higher performance singles.
 
bnt83 said:
Looks like most standard GA twins aren't much different than the higher performance singles.
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That's about right. The power upgrades (like what I listed) help push it higher, but the real benefit is OEI since you do lose 80% of your performance when you lose one. Comparing twins, the upgraded 310 is similar in power/weight to a Cheyenne II turboprop, but the Cheyenne performs better in climb. I believe this is due to bigger (more efficient) props and the lack of an engine nacelle around the prop to add drag and reduce thrust from the prop.

But, the twins will hold more stuff, which is usually the benefit.

The Chieftain I used to fly was 7250 lbs (with VGs) for 700 HP. Don't ever want to lose a fan in that plane...
 
The 300 missile on the M20J would be nifty. 3100 pounds gwt and 300 horses
 
I was looking at the 208 caravans, which is slightly higher loading than piston twins

208 - 675 HP & 8,000 Pounds = 11.851
208B - 600 HP & 8,750 Pounds = 14.583
208B - 675 HP & 8,750 Pounds = 12.962
208B - 867 HP & 8,807 Pounds = 10.158
 
RV-6. 160 hp, 1600 lb gross. 10 lb/hp.

Alternately, 160 hp, 1250 lbs lightly loaded. 7.8 lb/hp.
 
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