Posted: Tue Oct 25, 2005 6:00 pm
look at the weight and/or operating habits of modern bikes.
Modern cuisers tend to be quite heavy and pack sizeable CCs compared to older ones.
Modern sportbikes though much lighter than old ones are much higher strung in the engine room, plus many (possibly even most) sportbike riders like to twist that right wrist a LOT. RPMs also have a lot to do with fuel economy.
Higher RPMs = more injector pulses or more vacum in the carb = more fuel used.
The blast engine is a very low revving design. The engine in the blast in never operating in a very high duty cycle so it has less chance of detonation running a really lean mixture.
Most stock bikes and cars run richer than they need to to reduce NOX (Nitrides of Oxygen) emissions. These emissions are most prevelant on vehicles with very high combustion temps (sportbikes, high performance cars, diesel engines). NOX is one of the primary compenents of visible smog along with ozone and soot. The upside to high combustion temps though is lower emissions of Hydrocarbons, Carbon Monoxide, and Carbon Dioxide, not to mention more power and better MPG.
The better solution is Low sulfur fuel (europe has used this since around the turn of the millenium, the US adopts it in 2007). The lowered sulfur conent lowers NOX emissions far more than lowering combustion temps especially in diesel engines where is also significantly reduces the soot content as well.
Modern cuisers tend to be quite heavy and pack sizeable CCs compared to older ones.
Modern sportbikes though much lighter than old ones are much higher strung in the engine room, plus many (possibly even most) sportbike riders like to twist that right wrist a LOT. RPMs also have a lot to do with fuel economy.
Higher RPMs = more injector pulses or more vacum in the carb = more fuel used.
The blast engine is a very low revving design. The engine in the blast in never operating in a very high duty cycle so it has less chance of detonation running a really lean mixture.
Most stock bikes and cars run richer than they need to to reduce NOX (Nitrides of Oxygen) emissions. These emissions are most prevelant on vehicles with very high combustion temps (sportbikes, high performance cars, diesel engines). NOX is one of the primary compenents of visible smog along with ozone and soot. The upside to high combustion temps though is lower emissions of Hydrocarbons, Carbon Monoxide, and Carbon Dioxide, not to mention more power and better MPG.
The better solution is Low sulfur fuel (europe has used this since around the turn of the millenium, the US adopts it in 2007). The lowered sulfur conent lowers NOX emissions far more than lowering combustion temps especially in diesel engines where is also significantly reduces the soot content as well.