Contra-rotating engine revisited

"Kingfish" wrote in message
ups.com...

Steve Foley wrote:

How about an engine with the crankshaft running out the front and back,
so
you could mount a prop on the either end? That way you could have
counter-rotating props using the same engine.

Two props mounted on a common crank would turn in the same direction,
so they wouldn't be contra-rotating (I assume that is what you meant)
but might be counter-rotating if they turn in the opposite direction of
the other engine's props.

What I meant was putting a clockwise spinning prop on one wing, and turning
the other engine around, so it would be a counter-clockwise spinning prop on
the other wing.

Vacuum pumps are different (although these are accesories)
"Chris W" wrote in message
...
The previous post on this topic got me wondering. Just how different
would the two engines need to be? I'm no expert, but it seems to me
cam shaft(s), magnetos, and prop are the parts that would be different
from one side to the other. I almost forgot, reverse the polarity on
the starter motor. What am I missing?


--
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KE5GIX

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tom418 writes:

Vacuum pumps are different (although these are accesories)

What is the logic behind using vacuum to power instruments? Why not
just use an electric motor, or compressed air?

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic wrote:
What is the logic behind using vacuum to power instruments? Why not
just use an electric motor, or compressed air?


Why don't you just think about what FAA's answer to that one is.
So obvious a Caveman can figure it out. Plus, compressed air
can be and is used. But not electricity, unless....

F--

"TxSrv" wrote in message
. ..


So obvious a Caveman can figure it out.

Too many Geico ads?

This is annoying. "COUNTER-rotating" is the term you want.
"CONTRA-rotating" is when you have two different blades on the same
shaft spinning in different directions. About 50% of the time one of
these terms gets used, they get them mixed up.

http://en.wikipedia.org/wiki/Contra-rotating_propellers
http://en.wikipedia.org/wiki/Counter...ing_propellers

Chris W wrote:
The previous post on this topic got me wondering. Just how different
would the two engines need to be? I'm no expert, but it seems to me
cam shaft(s), magnetos, and prop are the parts that would be different
from one side to the other. I almost forgot, reverse the polarity on
the starter motor. What am I missing?

"Chris W" wrote in message
...
The previous post on this topic got me wondering. Just how different
would the two engines need to be? I'm no expert, but it seems to me cam
shaft(s), magnetos, and prop are the parts that would be different from
one side to the other. I almost forgot, reverse the polarity on the
starter motor. What am I missing?


--
Chris W
KE5GIX


Camshaft as you said.
Crank - they drill the holes for the oil to the rod bearings in a different
spot.
Magneto - the impulse has to work in the other direction. I don't know if
there are changes to the points for avaition applications.
Oil pump - has to pump in the other direction
Starter - the bendix is different, the brushes are re-located
Alternator - it may have a different cooling fan
vacuum pump
Prop as you said
Mechanical Tach, or the drive (I assume)

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Chris W wrote:
The previous post on this topic got me wondering. Just how different
would the two engines need to be?

If propeller direction is all that you need to change, could you just
add a reverser gear?

"Bucky" wrote in message
ups.com...
Chris W wrote:
The previous post on this topic got me wondering. Just how different
would the two engines need to be?

If propeller direction is all that you need to change, could you just
add a reverser gear?


How about one engine in the middle, with chain driven gears turning the
props on the wings.

Oh, wait. I think that's already been done.

"Bucky" wrote

If propeller direction is all that you need to change, could you just
add a reverser gear?

Before you come in here and play with big boys, you better put on your galoshes,
bucky.

And stop following that MX, from the sim group, where ever he goes. He and you
are going to get your fingers stepped on.

Maybe get a clue, too.

Oooh, that was mean. I take it back.
--
Jim in NC