Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: meger z on March 21, 2010, 01:38:59 PM
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the Japanese seem to bang on about zen = simplicity , so how do the square with 4 strokes over a 2 stroke which is pure zen ?
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LOL!
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If zen is simplicity, I would expect them to be running steam-powered bikes. Now THAT would have some torque!
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Hey Guys,
How's it going?
I wanted to reply here real quick because steam isn't actually all that simple! Check out how this valve gear works and then picture yourself calculating the levers and pitches to get this timing right!
Geezzzz.....
This illustrates the shift from forward to reverse.
http://en.wikipedia.org/wiki/File:Walschaert_gear_reversing.gif (http://en.wikipedia.org/wiki/File:Walschaert_gear_reversing.gif)
This is just the gear running straight. You could also adjust something called the "Cut Off" to almost-like shift up through the gears as the machine built up momentum. It was not a shift in output ratios like we do with bikes, it was more like if you had somethig on the handlebars that could move your transfer ports closer to the center of your piston's stroke as you built up speed and didn't need the long stroke cylinder charge/torque anymore, AND also moved the exhaust ports to take advantage of the new stroke length. Kind of like coming off the line with a +6 or +8 stroked engine, or a very over square engine, and then switching to square, and then under square as you built up speed, but having it all based on the way the cylinder was being loaded. Those engines only had 1 gear ratio, 2 Strokes of the piston = 1 drivewheel rotation. To have been able to start up a heavy load, and take it up to, or over 100 MPH with 1 drive ratio, relying ONLY on the throttle and the operator adjusted valve stroke and cylinder charge economy, is freaky genius!
http://en.wikipedia.org/wiki/File:Walschaerts_motion.gif (http://en.wikipedia.org/wiki/File:Walschaerts_motion.gif)
I a lot of ways, the 4 stroke motocross engine is a pudgy, Bessy-Cow compared to that. That was ancient mechanical genius, scratched out with equations on paper and then cast and machined by hand... HOLY SHIT!
Thanks,
Jim
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I've studied the Walschaerts valve gear in my spare time before. Yes, it does look quite complex, but you have to remember that what you're showing there is practically the whole engine. It's got no need for a clutch or transmission because of its insane torque delivery and low revs. I submit that even with the valve gear, a steam engine is simpler than even a modern two-stroke, when you take into consideration that the two-stroke does indeed require a transmission, with all its splines and bearings and dogs and shifting forks and shifting cam, etc.
I love steam engines because they don't have the freakiness of internal combustion. With internal combustion, you look at the diagram and think, "Okay, so all that happens 350 times a second. How fast is that? Oh, whatever." You sort-of have to check your common sense at the door when thinking about them, because simple instinct tells you that such fast motion is impossible. With steam, though, even at full speed you could look at it and the whole thing makes sense. Even if the pistons are stroking 11 times a second at 80mph (that's Doyle McCormick's quote on the SP4449), it's still an order of magnitude less than even a relatively low-performance internal combustion engine.
I'm lucky to have this beautiful beast living just fifteen minutes from my home. She's got 78,000lbf of tractive effort, making her one of the best passenger steam locomotives created in the steam era.
SP 4449 Michigan bound 7-3-09 (http://www.youtube.com/watch?v=MK5cYMGSmIs#ws)
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I started a thread about Zen now we have a steam train ?
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Meger z - you got to cut Jetzcorp some slack... he is stuck in the past, even though he is not yet 25!! :D :D
For those interested, ZEN = form of meditation, in the attainment of enlightenment. As such, it de-emphasizes theoretical knowledge in favor of direct, experiential realization through meditation and dharma practice.
I understand where you were going with your opening statement...
Two stroke = simple
Four-stroke = not so simple
Did I get it close?
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yep spot on :D .Iv been watching programs on Japanese factory's like honda Kawasaki and Suzuki ,There is always some nice flute music tranquility and some bloke from the company saying how the factory motto is all about zen and simplicity .What could be closer to zen than a 2 stroke .Simplicity is the last word i would use to describe a 4t >:D. Now i better learn to meditate :D