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#11
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Prop Balance and Murphy
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#12
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Prop Balance and Murphy
The same goes for the engine manufacturers. I put six new Millenium cylinders on about a year and a half ago, all the pistons within 1 gram. On a typical Continental they don't really care how much the pistons weigh. I don't have any love for Continental....But.....It is MUCH more important to balance rotating parts than reciprocating. |
#13
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Prop Balance and Murphy
"It is MUCH more important
to balance rotating parts than reciprocating." I challenge that. Acceleration of a mass (or mass error) creates the same dynamic force whether in a rotating motion or in moving in only a translational motion. The only difference is that the force direction is changing vs just reciprocating. One gram may be overly accurate but it is something that is easily achieved. I recall a Continental paper that said though that they deliberately built up an engine with one pound (!) heavier piston & it ran "satisfactorily". Yeah, I'll bet......! |
#14
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Prop Balance and Murphy
On Mar 18, 1:58 pm, nrp wrote:
"It is MUCH more important to balance rotating parts than reciprocating." I challenge that. Acceleration of a mass (or mass error) creates the same dynamic force whether in a rotating motion or in moving in only a translational motion. The only difference is that the force direction is changing vs just reciprocating. One gram may be overly accurate but it is something that is easily achieved. I recall a Continental paper that said though that they deliberately built up an engine with one pound (!) heavier piston & it ran "satisfactorily". Yeah, I'll bet......! If one cylinder is oversized by .010" , the opposing cylinder gets it, too. The heavier .010" oversize piston will throw everything out of whack otherwise. A one-pound heavier piston would run satisfactorily to someone else, not to most of us. It would shake pretty good. Might get you home, but that's about it. Dan |
#15
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Prop Balance and Murphy
If one cylinder is oversized by .010" , the opposing cylinder
gets it, too. The heavier .010" oversize piston will throw everything out of whack otherwise. A one-pound heavier piston would run satisfactorily to someone else, not to most of us. It would shake pretty good. Might get you home, but that's about it. A .010 inch oversize piston doesn't necessarily have to weigh more. And the piston area is less than 1 percent larger than standard. I don't think that would cause a rough engine, as typical ignition timing and mixture distribution variances will be much greater than that. But, a single 1 pound piston mass imbalance would give a typical engine crankcase vibration of about 3 ips, which would obviously be pretty rough to most of us. |
#16
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Prop Balance and Murphy
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#17
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Prop Balance and Murphy
I'm a serious woodworker
Dang. You can afford to fly AND do wood work? I've got a basement full of serious power equipment that has nary been touched since I learned to fly 14 years ago. With the price of cherry, building a dresser works out to way too many AMUs for me to justify doing both. You must be one of dem "rich playboy pilots"... ;-) -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
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