350 HP No pistons!
 

This company has a 110 lb electric motor rated at 350 HP @ 2500 RPM direct drive! Now all we need is Testla to make batterys to fit into our fuel tanks and firewall!

http://phys.org/news/2015-04-world-r...-aircraft.html

This one has been here before.....................

And at the same weight, cost, range, and refill rate.

Think it's more likely to be a lead in to a hybrid aircraft.

The weight savings would easily offset the installation of a small generator, easily fueled by 89 octane fuel. Gal/hour would be excellent... So, with the bladder being the lmiting factor, no need to carry 40-50 gal of fuel. Drop it to 10-20 gal tanks and more weight saved.

Overall, a huge reduction in operating/maintenance costs. Think it could be a great boost to GA.

A series hybrid may be the way to go, though weight and drag improvements will help in general. Anyway, take a gas/diesel sustainer engine sized for cruise power requirements and charging, plus a bit of margin. Hook that to a generator. Drive the prop(s) by electric motor, supplied by the generator and batteries with 10-15min of power. The stored electrical energy gives you the power boost for takeoff and initial climb, and they slowly get recharged during cruise for use in a go-around or engine out.

By this approach you can get insane takeoff power if needed (think near-VTOL performance, especially with a pair of folding props), and since the engine isn't directly driving the prop, you can run it at optimal RPM and you can use pretty much any engine you want, without worrying about torsional vibration or reduction gearboxes. It's also easier to integrate into the airframe and you can use an optimal cooling system (ducted radiators).

Hybrid systems work in cars because they recover energy from braking, and can use the electric motor to assist in acceleration, allowing a smaller gas motor which is more efficient in steady speed cruise. Neither of these situations exist in aircraft.

An airplane needs to make full power for hours on end, while a hybrid battery generally only contains minutes of energy. Your 89 octane generator still needs to be 180HP if you want to cruise as fast as your 180 HP Lycoming, and the fuel consumption of an engine like a Lycoming run LOP is really low for the power it produces. Most GA aircraft engines will already run happily on 91 octane, it's just that you can't get it at most airports.

You could get better takeoff performance in a plane with a hybrid system, but you aren't going to halve the fuel consumption, or even really reduce it at all. The gains that come would likely come from an optimized airframe with the new packaging that is possible.

You could probably fill the wings with Lithium batteries and still be light, maybe get a good few hours or more of flight time but who wants to sit overnight to charge the batteries on a Xcountry. The Tesla with charge 80% in ~ 20 minutes on 440 volts... But when will we see FBO's across the country that will have chargers... Maybe someday

Might get significant weight savings in the engine using a much smaller (cubic inch) higher reving, higher compression engine still producing cruise power. Think of say a 120hp turbo charged engine would produce same 9000 ft power as that 180hp lycoming does. Then add thin film PV to the wings to provide for recharging on the ground and a little extra power in the air.....
Engine quits and you have 15 min of full power to land. Put the engine in the tail, move the wing back, streamline the nose. I think I will start that mod right now. will only take a few hours I promise.

I do like the ideas, but still a long way to go before realistic for a cross country machine. Training aircraft that have 1 hr flight time with 30 min reserves is coming close to possible.

Remember the 5 1/4 floppy disc, now we have 512 GB card, who knew back then. Same with battery tec, I can't wait to see what the very near future brings us. :D

RV-8 Wing Area = 116 sq ft
Max sunlight = 100 W/sq ft
Thin film solar panel efficiency = 20%
Power = 2.3kW

120 HP = 90KW

You'd only need to charge in the sun for 40 hours of direct, intense, equatorial sunlight in order to fly for an hour. In flight, each hour of flight only adds about 80 seconds to the flight, the same as about 8 ounces of fuel.

As for a small, turbo engine, why go through the whole electric conversion and back instead of a gearbox? If you have a small engine that is reliable enough for an airplane, then you have something special already.