 The View Askew World Chat Champion

Joined: 29 Nov 2005 Karma :    
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 Posted: 19:43 - 23 Apr 2006 Post subject: Give me V-Twin Give Me Confusion |
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Is it so that ignition is timed for 2 cylinders so that 1 fires while the other is on its 2nd cycle? this would mean instead of 1 cylinder of say 125cc, there would be 2 of 62.5cc, both kicking out half the total possible engine bhp each time they fire, instead of the entire possible bhp every 4 cycles of the engine.
If so, is this to give a continuous supply of power at lower rpm?
If not, What is the point of 2 cylinders?
If I have entirely missed the point and made no sense whatsoever, got everything wrong could someone please explain?
Cheers.
Soul,  ____________________ "Do what you always did, get what you always got" |
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 Robby Dirty Old Man

Joined: 16 May 2002 Karma :   
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 Posted: 21:22 - 23 Apr 2006 Post subject: |
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More cylinders = smoother. You can also use a lighter flywheel, because the engine is providing its own torque for more of the 720 degrees, and doesn't rely on the energy of the flywheel to keep alive until the next bang.
More efficient in general, because of assorted reasons. Less of the energy is being used to spin a heavy flywheel, or a balancer shaft. The exhaust pulses on a twin or multi cylinder bike can be used to scavenge the other cylinders, i think on a single this would be harder to have because of the exhaust pipe length needed.
I presume a smaller cylinder gives a more efficient burn, but then you probably also have more piston ring are in contact with the cylinder wall overall, and thats more friction.
But thats all a bit of a tangent. To answer your question a bit better, remember that suck, squeeze, bang, blow takes 720 degrees. On a parallell twin this means you can either run 360 degrees out of phase, so each piston moves up and down together but one is on its induction cycle as the other is on its ignition cycle, or you can run them 180 degrees out of phase, which should give less primary vibration.
Confused? You should be. Stop smoking the weed and it might get clearer. |
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 The View Askew World Chat Champion

Joined: 29 Nov 2005 Karma :    
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 Posted: 21:39 - 23 Apr 2006 Post subject: |
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Nope I get it perfectly! cheers mate! karma given  ____________________ "Do what you always did, get what you always got" |
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