Quote:
Originally Posted by Grant-53
The Enfield is a fine engine that does run at a much higher rpm than a typical industrial engine. As for economy the Kubota engine is used in the Centurion kit car. One such build featured in other posts broke 200 mpg at the Green Grand Prix a few years ago. As for manufacturing costs there are a number of factors that influence finished selling price. If one is looking for a smooth cruiser then a triple is a good choice, see Triumph bikes. For more throttle response on a canyon carver a lighter, higher revving engine is preferred. Gearing will match the torque band to vehicle weight and drag.
|
I wonder how close an off-road, EPA-certified diesel engine is to meeting the requirements for an on-road motorcycle? I know motorcycles have much relaxed standards, overall, as compared to autos and light pickups, but I wonder specifically as it relates to PM and NOx (the two big diesel pollutants) how hard it would be to certify one of these Kubota's if a manufacturer took the notion of selling a Kubota bike as a production vehicle. I know that off-road equipment are going through tougher standards at this time, i.e. going to particulate filters and ULSD fuel, so I would say whether the current Kubota is at this standard or not at this particular time would have some bearing on it; and then there is the issue of NOx, which requires SCR for most applications. I don't know whether off-road applications will ever require this extensive NOx reduction or not, or even if MC on-road vehicles would ever need to get down to that ridiculous .07 gram level or not, but it doesn't seem economically feasible for either application to me.
I would think in either case, with a strict EPA certification in place and a prospect of a production diesel motorcycle; one cylinder would be far cheaper and more simple than multiple cylinders, since common rail would likely be a pre requisite, and a single cylinder wouldn't need a central fuel management system, because their only managing for one cylinder.