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The ultimate lightweight range extenders? rotary!

Posted: Mon, 18 May 2009, 17:21
by AMPrentice
Ummm the rotary will never die it seems.

AVL rotary

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Hybrid AC/rotary ICE

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The ultimate lightweight range extenders? rotary!

Posted: Mon, 18 May 2009, 17:49
by woody
At least you won't need a safety noisemaker speaker with a ported 13B driving your genset.


The ultimate lightweight range extenders? rotary!

Posted: Tue, 19 May 2009, 02:51
by AMPrentice
itll make double the noise and power if it was ported.
Surprisingly it doesnt seem to have direct injection
or roller bearings to reduce friction further and
improve economy substantially.
The new mazda rotary will be 22% more efficient so they
clearly have to catch up in that department.

The ultimate lightweight range extenders? rotary!

Posted: Tue, 19 May 2009, 04:53
by Electrocycle
rotaries are great for power vs size, and ok for power vs weight, but there are fundamental reasons why they can't be particularly efficient!

something about a very large combustion chamber surface area with a horrible shape :)

The ultimate lightweight range extenders? rotary!

Posted: Tue, 19 May 2009, 05:47
by Tritium_James
I want a gas turbine range extender - the generator will be nice and power dense at 30k rpm!

The ultimate lightweight range extenders? rotary!

Posted: Tue, 19 May 2009, 14:34
by Electrocycle
it's really hard to make a fuel efficient small turbine engine... They end up needing heat exchangers to recover a lot of the exhaust heat to get anywhere near piston engine efficiency.

power to weight is very nice though!

The ultimate lightweight range extenders? rotary!

Posted: Tue, 19 May 2009, 15:28
by Thalass
And gas turbines chew the fuel like crazy. At work in summer its not uncommon to go through a few hundred kg of kero in an hour with the aircon and power on. In winter with just the power on its still around 100kg per hour.

The ultimate lightweight range extenders? rotary!

Posted: Tue, 19 May 2009, 16:18
by Electrocycle
yep, turbine engines don't get much of the fuel's energy out. They run at much lower pressure ratios than piston / rotary engines.

The ultimate lightweight range extenders? rotary!

Posted: Wed, 20 May 2009, 17:27
by AMPrentice
for size and weight the rotary is still on its own.

Unless using a motorbike 250cc engine that make around 30hp

The ultimate lightweight range extenders? rotary!

Posted: Thu, 21 May 2009, 01:15
by antiscab
yamaha big bang engine (998cc) is around 180hp
present crop of 250cc engines are around 45hp.

Matt

The ultimate lightweight range extenders? rotary!

Posted: Thu, 21 May 2009, 01:36
by Thalass
I assume that's petrol? I'd like to see a 250cc diesel motor and what it could do. Mostly because it can run on a multitude of fuels. Namely the kero I can get from work for dirt cheap :P

The ultimate lightweight range extenders? rotary!

Posted: Thu, 21 May 2009, 02:09
by juk
Check out this aussie design bad boy 8 cylinder compact engine.

http://www.ox2engine.com/

The ultimate lightweight range extenders? rotary!

Posted: Thu, 21 May 2009, 05:50
by AMPrentice
the main thing is simplicity, economy and compact size.
Simplicity - easy to repair or rebuild
economy - speaks for itself
size - speaks for itself
so there is no use making more than a certain hp
in which it consumes as little as possible