Engine Sizing and Selection

Since you are using 2 engines, you are in a different position from
the typical experimental aero application as far as the reliability of
each individual componant, and the composite reliability of the system
as a whole. You haven't shared the particular engine configuration
you're planning (e.g. push-pull vs. left right) but the use of two
engines brings additional challenges and opportunities.

Opportunities:
Single ignition motors
Operation at high average outputs
Use of 2 stroke power plants.

Since you have 2 engines, you essentially have redundant everything,
completely decoupled. Real about my twin engine pitch at:

http://inline_twin.tripod.com/concept.html

There are very high output 2 stroke motors available around 1hp/lb.
Mainly adapted from snow mobile (Rotax) applications. Used as a
single, the realibility is below what most people desire, but as a
pair, its down right usuable.

Please share your engine configuration with the group.

Rotary- IMHO great possibilites, sports car engine- high power/weight
ratio for a conversion, fail soft operation (will not seize), 2
plugs/cylinder by default.

(Jay) wrote:


There are very high output 2 stroke motors available around 1hp/lb.
Mainly adapted from snow mobile (Rotax) applications. Used as a
single, the realibility is below what most people desire, but as a
pair, its down right usuable.
++++++++++++++++++++++++++++++++++++++++++

Dictionary.com

DOWNRIGHT = Thoroughgoing; unequivocal
USUABLE = ????

DOWNRIGHT useable -- to you, Fearless Fosdick....
in the safety of your padded cell and rarefied atmosphere.

DOWN HEREon planet earth....
Multi-engine LIABILITY is what it's called by
most experienced pilots that walk the walk.

BULL**** FLAG set for "double trouble".


Barnyard BOb -- multi-engine rated since 1969

"Barnyard BOb --" wrote in message
...

(Jay) wrote:


There are very high output 2 stroke motors available around 1hp/lb.
Mainly adapted from snow mobile (Rotax) applications. Used as a
single, the realibility is below what most people desire, but as a
pair, its down right usuable.
++++++++++++++++++++++++++++++++++++++++++

Dictionary.com

DOWNRIGHT = Thoroughgoing; unequivocal
USUABLE = ????

DOWNRIGHT useable -- to you, Fearless Fosdick....
in the safety of your padded cell and rarefied atmosphere.

DOWN HEREon planet earth....
Multi-engine LIABILITY is what it's called by
most experienced pilots that walk the walk.

BULL**** FLAG set for "double trouble".


Barnyard BOb -- multi-engine rated since 1969

Finally, something we both agree on. The only thing I have seen, not in
operable condition more than a Ford, is...
a two cycle rotexx.

Friends don't let friends fly two cycles.
--
Jim in NC

On Fri, 31 Oct 2003 22:23:04 -0600, Barnyard BOb --
wrote:


(Jay) wrote:


There are very high output 2 stroke motors available around 1hp/lb.
Mainly adapted from snow mobile (Rotax) applications. Used as a
single, the realibility is below what most people desire, but as a
pair, its down right usuable.
++++++++++++++++++++++++++++++++++++++++++

Dictionary.com

DOWNRIGHT = Thoroughgoing; unequivocal
USUABLE = ????

DOWNRIGHT useable -- to you, Fearless Fosdick....
in the safety of your padded cell and rarefied atmosphere.

DOWN HEREon planet earth....
Multi-engine LIABILITY is what it's called by
most experienced pilots that walk the walk.

BULL**** FLAG set for "double trouble".


Barnyard BOb -- multi-engine rated since 1969

Didn't we go through this discussion talking about inline twins.

A twin powered by two unreliable engines is just an underpowered
single waiting to happen.

--
dillon

Life is always short, but only you can make it sweet

Dillon Pyron wrote:

There are very high output 2 stroke motors available around 1hp/lb.
Mainly adapted from snow mobile (Rotax) applications. Used as a
single, the realibility is below what most people desire, but as a
pair, its down right usuable.


Didn't we go through this discussion talking about inline twins.

Yep.

A twin powered by two unreliable engines is just an underpowered
single waiting to happen.

In my real life flying experience...
Hardly that good, Dillon. 8-(

Wannabees love to dabble in 'loser concepts' since all it takes
is napkin, pen and an audience. It's the 'visions of grandeur'
thing and the Internet that keeps them keep hammering away.
If a whacky scheme is presented often enough, maybe, it can
somehow magically becomes legitimate? You know...
through the magic of 'new technology', ad nauseum.

It's new moon time.
Can hardly wait for the full moon phase.


Barnyard BOb -- over 50 years of flight

Barnyard BOb -- wrote:

It's new moon time.
Can hardly wait for the full moon phase.

On the planet earth, the new moon was a week ago. If your new moon
was yesterday, it could begin to explain much.

David O -- http://www.AirplaneZone.com

It's new moon time.
Can hardly wait for the full moon phase.

On the planet earth, the new moon was a week ago. If your new moon
was yesterday, it could begin to explain much.

David O -- http://www.AirplaneZone.com
+++++++++++++++++++++++++++++++++++

Although my new moon really wasn't yesterday....
It's was close enough for the intended purpose.
Your response could begin to explain much, too. g

Barnyard BOb -- over 50 years of successful flight

In article , Barnyard BOb -- says...

Although my new moon really wasn't yesterday....
It's was close enough for the intended purpose.
Your response could begin to explain much, too. g

Barnyard BOb -- over 50 years of successful flight

Hey Unka Bob
We didn't have a new Moon this year in our parts I think it's the Solar storms
in my neighborhood. Gravity is less too since my plane flys better since it got
cold...

Chuck (I looked in the mirror and saw my moon was sagging)S

Barnyard BOb -- wrote:

Although my new moon really wasn't yesterday....
It's was close enough for the intended purpose.
Your response could begin to explain much, too. g

I have been told that I defy explanation. As for the moon, however,
on my planet, Earth, the moon was closer to full than new yesterday.
A full moon and a total lunar eclipse will occur this coming weekend.
I expect that some barnyard animals might become especially agitated
during this period.

http://aa.usno.navy.mil/data/docs/LunarEclipse.html

David O -- http://www.AirplaneZone.com

Dillon Pyron wrote in message
A twin powered by two unreliable engines is just an underpowered
single waiting to happen.

And when that happens, you land and get it fixed. But in the mean
time you have an aircraft well powered by a pair of engines with power
to weight ratios difficult to match at a cost within the reach of the
working man, with a composite reliability that exceeds a single 4
stroke.

It's true that the lone 2 stroke engine is typically paired with
aircraft that land off field as matter of course (golf) or can put
down pretty much anywhere when there is a failure (powered parachute).
But there are applications where weight is of paramount importance
(Hey, isn't that every airplane?) like ultralights. So thats the idea
of the dual system. and of course less engine weight means, less
airframe structure required to support it, less power required to
lift, and less wing to support all that, and less fuel to push all
that, etc...

BTW, Isn't that RV-4 with the 13B in it sweet looking?
http://powersportaviation.com/images.../Airplane2.jpg
Getting rid of those cheeks really cleans things up. The RV-6 doesn't
seem like such a great fit since Vans already made the frontal area
large in anticipation of the opposed cylinder engine.