Contra-rotating engine revisited

Nomen Nescio writes:

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

You'd have to demonstrate that they explained it incorrectly; if you
misunderstood, no refund is likely to be forthcoming.

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

"Jim Macklin" wrote in message
...
MXs Maniac, sounds like a handle for a motocross rider or
wannabe...

Test for torque.

Jump your YZ400 and while in the air, open the throttle, why
does the front wheel move and which direction? Stab the
rear brake just before landing, why is that a bad idea?


Get your MSFS and setup the P51 Mustang with the big HS
prop. In flight at 75 mph and 100 feet, slam the throttle
wide open, report what happens?

For him, it probably causes the infamous "Blue Screen of Death".

"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?

Not speaking to the other items, but electric motors seldom run as well in both
directions. It has to do with the timing, or how far ahead of the rotation that
the magnetic fields, or windings are switched.
--
Jim in NC

"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

With two stroke engines it is easy. I did this once. All I needed to
do was exchange the field wires in the starter to turn it backwards,
and modify the advance mechanism in the distributor so the spark was
advanced in the new direction. It ran fine. This was to enable a
motorcycle engine to be used in a go kart, where the engine was mounted
backwards, behind the rear wheels. It was a twin Yamaha and the go
kart would pop wheelies like crazy.

tom

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
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"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. I'm sure they must need changed, if MX says it is due to something
else. Not.
--
Jim in NC

Sorry, but you are wrong here. As long as there is no load external to
the engine, it's own friction torque will have no external
manifestation. There will be an external torque, momentarily while the
engine is accelerated or de-accelerated.

tom


Mxsmanic wrote:
Steve Foley writes:

No, there is not.

Unless the engine is weightless and frictionless, it will exert torque
on the airframe whenever it is turning, even if there are no props.

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

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

That will have to be brought up before the Grand Canonical Ensemble. I
don't think they are meeting again for another two years.

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
for Email, make the obvious change in the address.

tom writes:

Sorry, but you are wrong here. As long as there is no load external to
the engine, it's own friction torque will have no external
manifestation. There will be an external torque, momentarily while the
engine is accelerated or de-accelerated.

If you run the engine in zero gravity, does the crankshaft spin while
the engine remains still, or does the engine spin while the crankshaft
remains still, and why?

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

"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?

Prop governor and oil pump drive gears if not on camshaft. Floating
crankshaft balance weights may be slightly different if those are used.

D.