jeroen
Expert Class
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posted September 28, 2005 11:53 PM
 Edited By: jeroen on 29 Sep 2005 01:00
Katana 6 cilinder?
Can it be true?
I guess it's a concept. Too much 'design' for my liking....
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Jeroen - BMW R850R
   
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OutsiderZX12R
Zone Head
Street Racer
Posts: 841
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posted September 29, 2005 03:28 AM
I'm looking at that FZ1 piece on the upper right corner.
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OutsiderZX12R
2000 ZX12R-A1
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jeroen
Expert Class
Posts: 144
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posted September 29, 2005 03:49 AM
There you go:
http://www.yamaha-motor-europe.com/products/motorcycles/street/fz1.jsp
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beansbaxter
Needs a life
Posts: 5911
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posted September 29, 2005 05:51 AM
Cant be a Katana! Its water-cooled!
I'd say it looks retro, like a CBX, But has the smile of a girl with braces.
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trenace
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posted September 30, 2005 07:56 PM
Edited By: trenace on 30 Sep 2005 21:22
The article describes it as a concept bike only, and -- while having the intent of creating a positive spin on the possible ultimate reality of concept bikes -- the article points out that Suzuki's B-King concept bike was shown in 2001 but won't be coming out in 2006. So if this were to follow the same pattern, it might be due in 2010.
In other words, there's not a lot of reality to the above, as Suzuki's design cycle is well shorter than five years. It's a show bike. The same people that designed this will likely be involved in the design of future bikes, and so it can at least be taken from this that some people at Suzuki like this idea. But there are many ideas that some like, that never make it.
As for "not being a Katana," of course it's opinion as to what is and what is not, but it would also be fair to say that if something is a decent-handling bike, it is not a Katana, and if it is a remotely decent bike to ride day in day out, or for that matter even once for any length of time whatsoever, yet not for any handling advantages to show for it, it is not a Katana. 
I would like to see a 6-cylinder bike again, but even though I do not much like V's for bikes (exhaust routing), it seems to me that a V6 would make more sense than an inline. Though if an inline 6 can be made no wider than the ZX-12R's engine yet have 1100 cc displacement or better AND be a reasonable short-stroke design, that could work. However it seems to me that that is probably physically impossible.
The article does claim that the engine in the show bike is the exact same width as a 1000cc Fireblade motor. That could be one of three things:
1) It might be a very narrow bore, long stroke motor. If so, then BFD. The biggest advantage of more cylinders for a given displacement is allowing higher rpm from shorter stroke. If instead you're getting the same displacement despite half again more cylinders just by reducing the bore, little to nothing can be expected from that.
Or, as a more precise (though not necessarily dead-on) estimation, if you reduce the bore by 18.33 percent so as to get the same displacement out of half-again as many cylinders, then on assuming power to be proportional to the 1.65 power of bore if equal efficiency then power per cylinder should drop to about 71%. With half again the cylinders, you wind up with a grand total of seven percent more power. Yippee yahoo. Could have done that staying with 4 cylinders but just increasing the displacement to 1200 cc.
2) The show bike may not have a real motor so the figure means not a damn thing.
3) Maybe they do a trace better than example 1 and actually do reduce the stroke a little compared to a Four of comparable displacement, in which case the performance improvement could be a little better than in that above case.
Though it doesn't seem believable that they could have maintained typical bore/stroke ratios and still kept that width, suppose that they had... in that event power could be improved by 12% for the same displacement by virtue of the extra cylinders, assuming equal efficiency.
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beansbaxter
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posted October 01, 2005 02:43 PM
quote:
It might be a very narrow bore, long stroke motor. If so, then BFD.
Gnot Gnessescarily Grasshoppah - consider the effect of rod-to-stroke ratio, square or undersquare engines can can be made to rev to the moon, or at least into orbit, by manipulation of rod length compared to stroke travel.
It's not generally considered the elegant solution, and certaintly wouldn't be in this case (being used) for aesthetics, but it is possible to build a modern high reving engine within less than optimum layout dimensions when space restrictions require it.
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Zammy
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posted October 01, 2005 05:25 PM
I will buy the PISS outta' this bike !!! I'm getting REALLY tired of the status quo inline four.
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lizard
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posted October 01, 2005 07:54 PM
That Yammi is funkadelic
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trenace
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posted October 01, 2005 09:13 PM
Edited By: trenace on 1 Oct 2005 23:04
Beans, I'll try to find for you a spreadsheet I either saved somewhere or can find again that computes piston speeds and accelerations at each degree of travel for whatever rod ratios you select... and also hopefully a similar sort of thing on side loading.
You are correct of course that with higher rod ratio somewhat higher nominal piston speeds (that obtained as an average simply from stroke and rpm) can be the case for the same accelerations, or in other words the bottom end can stand a little more rpm. However the difference in rpm's allowed for same accelerations is not as much as one might hope, particularly if considering only modest differences in rod ratio. Surprisingly subtle actually.
Exactly how a manufacturer could both make an engine unusually long stroke (to compensate for unusually narrow bore) AND have unusually high rod ratio without getting an unacceptably tall engine for a motorcycle, I don't know. So it seems hard for me to assume that this bike would have a rod ratio much higher than current bikes.
It's a pity how much height is needed for a large improvement in this parameter... I'm going to the trouble of 3 mm longer rods myself but I expect this to be only a quite small effect. To go to a F1 sort of rod ratio would require about 2 inches greater deck height... and there's no way that would fit well.
Actually I expect this has considerable relevance to the 14 as well... to handle its greater stroke, I will bet you its rods are at least 9 mm longer, in which case the deck height must be about a half-inch higher or even more. For the 15F Jet Ski motor the difference is even bigger: Kawasaki chose to "correct" the 12R's quite low rod ratio and apparently went to about 1.79 for that motor, with the result being a deck height nearly 2 inches greater. Not "too tall" for a bike by say the standards of that new Yamaha V-Twin-with-R1-wheels-and-suspension cruiser, but so tall (and probably so much crank inertia) as to start getting kind of unrealistic for a supersport bike I would think.
Suzuki would be facing the same thing here... the longer the stroke and the longer the rods, the taller the engine gets, this being particularly relevant with a pure downdraft design, and there gets to be a limit to this, as well as a point of no real returns well before that.
And certainly there's nothing in that pic that seems to suggest unusually high rod ratio combined with a long stroke.
Personally, on that general subject, I'd be interested to know the width of the ZX-10R's block, and if I knew that I'd figure how much wider it would be as a 1250 Five.
If no wider than the 12R block, that would be pretty awesome... if you figure the 10R as say 148 rwhp (just to have a figure, some dynos could give that) then a Five based on it might deliver around 185 hp at the rear wheel. And yes inline Fives are smoother than Fours, or can be. (And also, incidentally, I think could be more amenable to "big bang" concepts.)
The Six I think really is too wide for a supersport motor... there's a reason neither Kawasaki nor Honda repeated their efforts from the 70s. The Five, however, might be reasonable... or possibly might also be too wide or alternately too narrow-bored for any given width. Dunno. The width of the 10R's block would help give an insight into that.
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beansbaxter
Needs a life
Posts: 5911
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posted October 03, 2005 02:54 PM
Edited By: beansbaxter on 3 Oct 2005 15:55
Correct on all counts. Sometimes I just have to drag that out to see if it will get a response. It's absolutely amazing how many gearheads are not aware of the effects of changes in engine geometry. Thanks for not being one of them!
quote:
or in other words the bottom end can stand a little more rpm. However the difference in rpm's allowed for same accelerations is not as much as one might hope, particularly if considering only modest differences in rod ratio. Surprisingly subtle actually.
Total reciprocating mass becomes a limiting factor in the extreme ranges of long rod motors also.
The Cycle World tech article I was refering to started with a mention of piston design, and how the latest designs will sit on the pin bosses when placed on a flat surface, whereas in the past the thrust edges of the skirts have traditionally been the lowest point.
Seeing that kind of design change represents a complete departure in mass distribution and heat path conduction from what has been considered the conventional norm for a long long time.
Obviously no good can come of this, such parts are completly useless outside of a pure race engine...
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OutsiderZX12R
Zone Head
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Posts: 841
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posted October 03, 2005 06:41 PM
Edited By: OutsiderZX12R on 3 Oct 2005 19:42
quote:
There you go:
http://www.yamaha-motor-europe.com/products/motorcycles/street/fz1.jsp
Thanks Jeroen. 
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OutsiderZX12R
2000 ZX12R-A1
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lizard
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posted October 04, 2005 03:47 PM
Edited By: lizard on 4 Oct 2005 16:51
She is trapped by that thing .
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OutsiderZX12R
Zone Head
Street Racer
Posts: 841
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posted October 05, 2005 04:16 PM
It must scare her!! It is kinda sinister looking
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OutsiderZX12R
2000 ZX12R-A1
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DB
Pro
Posts: 1932
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posted October 14, 2005 06:24 AM
They're putting a full fairing on it and labeling it with the Hayabusa name.
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Dan
04 ZX10r (Track only)
08 Concours14
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