IMM wrote:

"Bob Mannix" wrote in message
...


thing. (There are very few Wankel-engined aircraft or

helicopters,

many

are

one-offs, and I can't find a single reference to a twin-engined

helicopter.)

Try for starters:
http://home.earthlink.net/~rotaryeng/ACRE.html
http://www.deadbeatdad.org/eliptoid/history.html


I did try these, and they are quite interesting. However I couldn't

see

any

twin engined helicopters. There are clearly some (being generous, more

than

"very few") Wankel engined aircraft but they do seem to be mostly

one-offs.

On the whole I would say the refernces supported what John said!

Which was what?

"(There are very few Wankel-engined aircraft or helicopters,
many are one-offs, and I can't find a single reference to a twin-engined
helicopter.)"


Go he
http://home.earthlink.net/~rotaryeng/ACRE.html

Do a find on helicopter. US and Russian come up. The US heli is not a

one

off, being a production model. Rotaries are popular with light aircraft

for

obvious reasons.


Actually if you do a find on "helicopter" you get nothing. This is because
they spelt it "helicoptor" (which is hardly your fault)!


I searched on "heli".


However there are two (that I missed). It's not at all clear from the
pictures or the rest of the Russion VAZ site that it is a Wankel engine

but

I'll take their word for it. Without being "funny", having seen some of

the

photos, you wouldn't catch me up in it!

The US one, as you say, is a proper jobby and all that it claims, clearly.

Neither is a twin engined helicopter, as John said.


The Ruskies do a twin wankel jobbie, and their version of a rotary, in
development, is quite neat. Instead of a triangular rotor, they reverse it
and have a triangular chamber with the seals in the block. The mixture is
injected via the rotor, like injecting via a piston in a piston engine.

When you see what is in development all around the world and the big car
companies say there is no future in rotaries, you realise they are talking
balls. Thee is some brilliant work out there. They want a proven design to
be given to them, so they can tool up for it, if they can be bothered. They
don't want to spend money on R&D.


Ther is no future in ANY IC engine.


The theroteical adbvantages of et Wankel engine are slkight, and modern
materials and electronics habve made standard piston engnes as good as
the theory says any heat engine - wankel included - is likely to get.

WEankles are a bitch to mass produce - the epicycloidal shapes require
specialised CNC machining - and the seals were always a problem. In
short, great, but no cigar. Ther was a little advantage in racing as teh
power to weight was pretty good, but relaibility was always an issue.