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400hp, 280 ft - lbs of torque and only 88lbs

Actually, it's operated at 7500rpm so a nice 2:1 would do the trick. However, I'm more intreagued by the electricity "stint" power technology they plan to use for the first lap - an electric RV-12, anyone?

The quick rule-of-thumb calculation figures out to almost exactly 7,500 RPM.

I wonder if that is SAE certified?

4.5HP per pound. I didn't think it was even possible to generate that kind of torque with so little mass!
 
4.5HP per pound. I didn't think it was even possible to generate that kind of torque with so little mass!

Lots 'o' boost makes lots 'o' hp. The F1 turbo engines were making 1200-1500hp from 1500cc 30 years ago on qualifying boost...
 
F1 motors

I'm a big fan of F1. But I think our motors need to last more than 2 hours.
 
Yep

......... I didn't think it was even possible to generate that kind of torque with so little mass!

My PT-6 makes 680 SHP, 1600 lbs of torque, weighs 325 lbs. It does this on takeoff with the compressor disc spinning 37,500 rpm! (not a typo)... and has 9500 TTSNEW. Prop is geared down to 2200 rpm, max, on takeoff. I had the gearbox rebuilt at 9,000 hours.

Best,
 
My PT-6 makes 680 SHP, 1600 lbs of torque, weighs 325 lbs. It does this on takeoff with the compressor disc spinning 37,500 rpm! (not a typo)... and has 9500 TTSNEW. Prop is geared down to 2200 rpm, max, on takeoff. I had the gearbox rebuilt at 9,000 hours.

Best,

Yeah, that "angular velocity" and thermodynamics will do that for ya. I guess I should have qualified that with "...from a piston driven engine."

Its still only a horsepower to weight ratio of about 2:1. given allowances for "brake horsepower" vs "shaft horsepower, I suspect that that's still not even close.

The N-model Hueys use 2 PT-6s joined together by a combining gear box. I used to hate pulling those things!;)
 
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My PT-6 makes 680 SHP, 1600 lbs of torque, weighs 325 lbs. It does this on takeoff with the compressor disc spinning 37,500 rpm! (not a typo)... and has 9500 TTSNEW. Prop is geared down to 2200 rpm, max, on takeoff. I had the gearbox rebuilt at 9,000 hours.

Best,

How's the fuel flow rate with that PT-6 at takeoff power? :D :p :eek:
 
Neal, not sure about fuel flow at takeoff but working at 2000 Prop RPM's and 1300 lbs of torque, it burns close to 47 GPH, so takeoff is probably close to 60 GPH:eek: an 8 hour day will cost around $1,500 @ $4.00/gal...I buy 6,000 gallon tanker loads. We also 'hot load'...the engine keeps idling. This to avoid thermal shock and minimizing 'cycles.'

Best,
 
Impressive. (the 88 lb 400 hp piston engine; turbines are always impressive, both in power & the quantity of fuel that flows through them)

Of course, you can assemble an all aluminum Mazda 13B rotary (with aftermarket aluminum side housings) that comes in at around 110 lbs for the 'long block' & will comfortably and reliabley make 250 HP normally aspirated, and it's available to normal humans today. And work longer than 2 hours.

A reduction drive to handle 300 HP weighs around 45 lbs. Airboat redrives for big V-8's come in at around 70 lbs.

Charlie
 
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Each horsepower produced takes a certain amount of fuel to feed it... doesn't really matter what the horsepower to engine weight formula is.... or really all that much whether gasoline or jet-a/kerosine/diesel is the fuel being burned, the formula that states how much fuel has to be burned to make X amount of horsepower cannot be dismissed and must be obeyed no matter how much it hurts our wallets. The bottom line is it costs a lot of money to defy gravity. :eek:
 
You got that right...

Each horsepower produced takes a certain amount of fuel to feed it... doesn't really matter what the horsepower to engine weight formula is.... or really all that much whether gasoline or jet-a/kerosine/diesel is the fuel being burned, the formula that states how much fuel has to be burned to make X amount of horsepower cannot be dismissed and must be obeyed no matter how much it hurts our wallets. The bottom line is it costs a lot of money to defy gravity. :eek:

Amen brother...

http://www.youtube.com/watch?v=FzCsDVfPQqk
Seven and a half million pounds of thrust

V/R
Smokey

PS: Saturn 5 still the most powerful and efficient thrust ever produced
 
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Yeah, that "angular velocity" and thermodynamics will do that for ya. I guess I should have qualified that with "...from a piston driven engine."

Its still only a horsepower to weight ratio of about 2:1. given allowances for "brake horsepower" vs "shaft horsepower, I suspect that that's still not even close.

The N-model Hueys use 2 PT-6s joined together by a combining gear box. I used to hate pulling those things!;)

The version Pierre has is down rated for very long life. The PT6 can and does make more then 1200hp in other applications. Pretty amazing engine considering it's at least a 40 year old design.
George
 
PS: Saturn 5 still the most powerful and efficient thrust ever produced

Careful there...when measuring efficiency of rocket engines, we refer to Specific Impulse, with units of Seconds

Typical values:

F-1 (used on Saturn V) 260 secs
SSME (now RS-25) 450 secs
Merlin D (SpaceX) 310 secs
RL-10 460 secs

We could put up some thrust to weight values also, and see that the F-1 does not "win" that discussion either, but as someone pointed out, in rocket engines, what difference does the weight of the engine make in terms of its performance? Certainly it's important to the overall vehicle, but for liquid fueled rocket engines, weight becomes a secondary consideration.

While the mighty F-1 engine was an awe inspiring engine, we can't say it was the most efficient. After all it was a LOX/Kerosene engine, whereas the RL-10 was a LOX/Hydrogen.

Also, to others, make sure to refer to the modern merger of two old competitors as "Pratt & Whitney Rocketdyne." It was a hard pill to swallow, but they are now one company.

And for further reading for those interested, I refer you to this little article.

Now back to our regularly scheduled RV programming. :)
 
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27000 pounds thrust/18K airplane....

Careful there...when measuring efficiency of rocket engines, we refer to Specific Impulse, with units of Seconds

Typical values:

F-1 (used on Saturn V) 260 secs
SSME (now RS-25) 450 secs
Merlin D (SpaceX) 310 secs
RL-10 460 secs

We could put up some thrust to weight values also, and see that the F-1 does not "win" that discussion either, but as someone pointed out, in rocket engines, what difference does the weight of the engine make in terms of its performance? Certainly it's important to the overall vehicle, but for liquid fueled rocket engines, weight becomes a secondary consideration.

While the mighty F-1 engine was an awe inspiring engine, we can't say it was the most efficient. After all it was a LOX/Kerosene engine, whereas the RL-10 was a LOX/Hydrogen.

Also, to others, make sure to refer to the modern merger of two old competitors as "Pratt & Whitney Rocketdyne." It was a hard pill to swallow, but they are now one company.

And for further reading for those interested, I refer you to this little article.

Now back to our regularly scheduled RV programming. :)

Don,
And who said RV dudes weren't Rocket Scientists...:)

V/R
Smokey
I still grinned every time I plugged the GE F110 into full AB!

www.iamanet.org
 
...Also, to others, make sure to refer to the modern merger of two old competitors as "Pratt & Whitney Rocketdyne." It was a hard pill to swallow, but they are now one company.
...

I realized today that Pratt & Whitney Rocketdyne is now Aerojet Rocketdyne, which is another marriage of two former competitors. Apparently P&W is now completely out of the rocket engine business. Rocketdyne has a rich history in the rocket engine business. They began as a unit of the old North American Aviation, the same company that built the P-51, B-25, F -86, F-100 and X-15, among others.

So the F-1B engine will be produced by Aerojet Rocketdyne.
 
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I hate to burst Nissan's bubble, but all the pictures on the OP's URL are CAD renderings - including the engine the guy is holding! Obviously he's not a CAD rendering (or is he...?) but I'll bet they photoshopped out the pimple on his nose in the process...

Marketing department being paid overtime.
 
:eek:
I hate to burst Nissan's bubble, but all the pictures on the OP's URL are CAD renderings - including the engine the guy is holding! Obviously he's not a CAD rendering (or is he...?) but I'll bet they photoshopped out the pimple on his nose in the process...

Marketing department being paid overtime.

And what makes you so sure of this?
 
Careful there...when measuring efficiency of rocket engines, we refer to Specific Impulse, with units of Seconds

Typical values:

F-1 (used on Saturn V) 260 secs
SSME (now RS-25) 450 secs
Merlin D (SpaceX) 310 secs
RL-10 460 secs

We could put up some thrust to weight values also, and see that the F-1 does not "win" that discussion either, but as someone pointed out, in rocket engines, what difference does the weight of the engine make in terms of its performance? Certainly it's important to the overall vehicle, but for liquid fueled rocket engines, weight becomes a secondary consideration.

While the mighty F-1 engine was an awe inspiring engine, we can't say it was the most efficient. After all it was a LOX/Kerosene engine, whereas the RL-10 was a LOX/Hydrogen.

Also, to others, make sure to refer to the modern merger of two old competitors as "Pratt & Whitney Rocketdyne." It was a hard pill to swallow, but they are now one company.

And for further reading for those interested, I refer you to this little article.

Now back to our regularly scheduled RV programming. :)

Interesting stuff. Efficiency is a measure of [something] produced divided by the potential theoretical maximum of some other thing(s) to produce that something. This may not always be a practical measure, but it is a correct measure. Thrust to weight ratio is not a measure of efficiency and neither is ISP. I guess in vacuum the ISP would have a one to one correlation with efficiency, but it is still not efficiency because the unit is seconds.

A "better" term for efficiency would be to use the total kinetic energy at the end of the stage or at some altitude divided by the total available (propulsion) energy at launch. This may be very impractical, but it is the reason why the F-1 probably is the most efficient engine, because you do not only have to convert chemicals to thrust, you also have to push a big tank of chemicals through the atmosphere.
 
Interesting stuff. Efficiency is a measure of [something] produced divided by the potential theoretical maximum of some other thing(s) to produce that something. This may not always be a practical measure, but it is a correct measure. Thrust to weight ratio is not a measure of efficiency and neither is ISP. I guess in vacuum the ISP would have a one to one correlation with efficiency, but it is still not efficiency because the unit is seconds.

A "better" term for efficiency would be to use the total kinetic energy at the end of the stage or at some altitude divided by the total available (propulsion) energy at launch. This may be very impractical, but it is the reason why the F-1 probably is the most efficient engine, because you do not only have to convert chemicals to thrust, you also have to push a big tank of chemicals through the atmosphere.

There are many terms in rocket science, as well as in engineering in general, that don't "make sense." I am not here to defend them. I was just sharing the way we do business. Surely you wouldn't argue with the likes of Werner von Braun, Robert Goddard and a host of others who fully understood how a rocket engine works. Contrary to your position, Specific Impulse, Isp, is the way we evaluate the efficiency of rocket engines. LOx/Hydrogen engines are much more efficient than LOx/Kerosene engines. Rocketry 101 class teaches us that.
 
Contrary to your position, Specific Impulse, Isp, is the way we evaluate the efficiency of rocket engines. LOx/Hydrogen engines are much more efficient than LOx/Kerosene engines. Rocketry 101 class teaches us that.

I won't argue with that. Oxidizing hydrogen in pure oxygen is the one of the most effective practical form of combustion in terms of energy per mass unit, not just for rockets, this is basic chemistry.

A diesel engine is more efficient than a gasoline engine due to higher compression ratio. This does not mean that a diesel engine always is the most efficient engine to use in all sorts of vehicles. When the demand for HP, speed, acceleration and deceleration goes up, and weight becomes an issue, a gasoline engine is more efficient. Race cars and motorcycles. At even more increased demands for acceleration, a two stroke is more efficient - snowmobiles and motocross. When weight and size becomes important for propulsion, a turbine is more efficient, even though it is abysmal in terms of efficiency compared with other engines (except for large prime movers with recycling/regeneration were weight is no issue).

Even though a diesel is the most efficient combustion engine, a very simple gas turbine with low thermal efficiency or BSFC is in fact much more efficient in an average sized airplane due to the power density, weight per HP and/or size per HP. It is the same thing with the F-1 rocket engine. It is a launch engine to launch a rocket through the lower parts of the atmosphere where aerodynamic drag is a major factor. Using a LOx/Hydrogen engine is simply not the most efficient way to do it. The increased combustion efficiency of hydrogen will not weigh up for the decreased power density.

Back to the 3 cylinder engine. It is to be used in a hybrid race car. A common misconception about hybrid cars is the increased efficiency is due to regenerative braking, probably because this is an easy concept to grasp and is therefore the focus of commercials. Regenerative braking is in fact just a small part. The main part is a very clever system of charging and discharging the battery in a way that allows the combustion engine to run at optimal efficiency at all (most) loads for typical driving patterns consisting of stops and starts and acceleration and deceleration etc, all these things that normally destroys the efficiency of a combustion engine. That's why I think an hybrid airplane is a bad idea. The typical "driving" pattern is very different and a variable pitch would handle the optimization of the efficiency much better with minimal losses.
 
:eek:

And what makes you so sure of this?

The lack of threads on the AN fittings of the oil pump for starter. Then there's the lack of threads in the crankshaft flange, the curious way the engine doesn't seem to deform the guy's jacket, the strange layup of the carbon-fibre components (not strange really, that's the way CAD packages tend to render CF components without care...) - more obviously seen in the other pictures - and the fact that if that guy really was holding 40kg of engine, he'd be struggling a little more than he appears to be...

Oh, and the lack of a real-world background screams photoshop!
 
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