Thread: light twins?
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  #29  
Old July 28th 05, 01:41 AM
Charlie
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Mark Smith wrote:
Frank van der Hulst wrote:

Bellsouth News Server wrote:

What would be better than a single, would be a smaller two rotary.


Whatever happened to the motorcycle rotaries? IIRC Suzuki had a 500cc
rotary in a motorcycle about 20 years ago. And Norton too?

I'd guess that a rotary of this size would be ideal for a microlight
aircraft.




All this talk about the rotary engine.

If they were this great, would there not be at least a couple cars
running them ?

Mazda RX-8 Renesis. The 6 speed manual transmission model makes around
250 hp without being turbo or super charged. The core 'short block'
engine weighs around 170 lbs. They are perfectly happy making rated hp &
more all day long as long as they have proper oil & water temps.

The reason for so much talk about them as a/c engines is that the core
engine is just about bullet proof at any power level likely to be used
in a GA aircraft. If someone made a small 2 rotor it would likely be
slightly heavier than a 2 stroke of equivalent power but much lighter
than a 4 stroke & have much higher reliability than the 4 stroke. The
guys flying the 2 rotor Mazda engines say the fuel burn is only slightly
worse than Lycomings of equivalent power so there's not much penalty there.

It's actually better suited to a/c use than in cars, due to the way it
responds to intake tuning & the fact that it's not very fuel efficient
until power output is at a high level, unlike piston engines. The cars
have incredible Rube Goldberg intakes to keep the engine 'on the pipe'
over a wide range of rpms; this isn't needed in an aircraft. It responds
to intake tuning like 2 strokes respond to exhaust tuning. (It's a true
4 stroke engine, though.)

More than you ever wanted to know?

Charlie