Contra-rotating engine revisited

Recently, Morgans posted:

"Nomen Nescio" wrote

Dammit! I'm calling MIT tomorrow to demand my money back.
Those *******s told me that it was proportional to angular
acceleration.

Naahhh. Just go ahead, and put in for an official change in the laws
of Physics.

Sorry, but that change isn't scheduled before the release of Real World
2.0.

Neil

Morgans wrote:
And stop following that MX, from the sim group, where ever he goes.

huh?

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.

Come to think of it, if an engine had contra-props mounted front & back
(like the old Dornier Do X flying boat from the 30's) the props' torque
would cancel each other's out but would there still be a torque
reaction from the direction of engine rotation? I'm assuming the Do X
props were contra-rotating, not 100% sure on that.

"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.