Quote:
Originally Posted by DragBean
The majority of the energy from gas is lost as heat in a piston driven engine. A piston driven engine has to convert the chemical energy of the gas into thermal energy before it can extract that energy in the form of mechanical energy via expansion of gas. Once again if all the energy in the gas were to be released at TDC that would allow the piston to extract the most amount of thermal energy possible. A faster flame front directly correlates to the speed the chemical energy is released.
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While this is true, the gases remain in the cylinder the same amount of time in contact with the cylinder walls, regardless of their flame speed. Improving on this, as I understand it, would require both a change in fuel, and a physical redesign of the engine block.
Honda has been working on this for decades. Back in the 80's they were designing cylinder heads that had multiple spark plugs for each cylinder, and valves that opened asymmetrically (in a very specific way) so as to encourage atomized fuel to only occupy a specific region inside the head. More modern engines also use index plugs, offset crankshafts, and some other things I'm sure I'm forgetting.
Again, I'm pretty certain that advantages of a different flame front could be had, but in a
highly tuned engine, such as the Honda engines that members on this forum regularly already get 75-100mpg out of, it's going to require mechanical redesign as well.