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Old 06-25-2016, 07:27 AM   #91 (permalink)
gregsfc
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Quote:
Originally Posted by sendler View Post
Very nice post but I wonder if you should go ahead and copy this to your own thread about the CTX since this thread is wandering all over the place all the way to such ridiculous machines as motorcycles with V8 auto engines.
Yeah. Probably. I was reading through this thread with a renewed interest in powered two wheeling, since I'm riding the CTX700 again after a long hiatus, knowing that I had a bike with an engine that came out of Honda automotive, but not expecting to read a couple of old comments inquiring about my specific model that barely justifies production in sales.

I thought that (hey) someone has asked about the potential of my bike if anyone who owned one ever cared about mpg and mpg tracking . Never expected to come across such a post anywhere; got excited and posted sort of a report or log of my experience, but really don't know the most appropriate way to spout off or even if I should as a new reader.

Just got carried away. But going back to the OP's inquiry, just so everyone who stumbles upon this thread who might care knows, Honda Power Sports developed an mc engine around 2011 that has its roots from Honda automotive with a rev limit at or about 6500 RPM; basically halving a 1.4-liter that is used in the Fit for North America, and developed it for a group of motorcycles that are very efficient for their displacement. They also borrowed some auto-engineering prowess to bring dual-clutch automatic, with sport and manual modes they call DCT. The models include, but are not all available everywhere: NC700S/SD, NC700X/XD, CTX700N/ND, CTX700/D, INTEGRA, NM4. Europe and maybe some other markets have an updated, bored out version of the engine that have the 750 nomenclature. From my perspective, as a whole, except for the small but growing cult around the NC700X and NC700XDCT, the American riding cultures absolutely reject the concept and prospect of Honda's great low and midrange performance and great mpg at the sacrifice of good higher-end performance.

If this Honda engine has been discussed in other threads, I apologize for the rehash above, but the whole premise of the thread starter brings up something near and dear to my heart. This whole idea that the only or best approach for maximizing mpg of mc's (as has been proclaimed by some elsewhere) is to take as small as possible displacement engine to generate minimum necessary horsepower to maintain highway speeds streamlined, is somewhat flawed or at least somewhat closed minded. Even though I'm not really physics and mechanically minded, I can see what I see and when I see Fred's naturally-aspired, larger, heavier, stock-like diesel bike, running on a less-dense fuel, with 31 hp and 35 peak pound torque, exceed the mpg of 250 cc and below stock bikes that have far less peak numbers, in a lighter package, resulting in comparable overall performance of the two approaches, that shows me that, using auto engine tech and even handicapped diesel technologies can produce at least equal mpg performance as does the minimalist approach.

So my only point is that, even though I don't have the knowledge to explain why it is so, I feel confident that there is some mpg benefit to added midrange power via higher, low-end torque that we get from the auto engine industry, and that, if there were ever an all-out manufacturing effort to produce high mpg mc's that were reliable, durable, and refined, the engine would be auto tech inspired; it would be bigger displacement than 250-350 cc class, it would be heavier than the current streamlined bikes, and if costs made it possible, it would be an all-aluminum, sequential turbo, direct -injection diesel with limited compression ratio on the order of at or about 15:1, because the state of modern diesel tech is way ahead of what many have assumed on this thread by some and there is alot of possibilities of diesel applications these days and that, really, the only things that limits diesels these days are costs and emissions compliance complexities, but that this latter hurdle is somewhat relaxed due to the lower standards for mc's.

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